Effects of exercise intensity and duration on the excess post-exercise oxygen consumption

The contribution of energy systems during 30-second lower body Wingate anaerobic test in combat sports athletes: Intermittent versus single forms and gender comparison

Combat sports, encompassing a range of activities from striking and grappling to mixed and weapon-based disciplines, have witnessed a surge in popularity worldwide. These sports are demanding, requiring athletes to harness energy from different metabolic pathways to perform short, high-intensity activities interspersed with periods of lower intensity. While it is established that the anaerobic alactic (ATP-PC) and anaerobic lactic systems are pivotal for high-intensity training sessions typical in combat sports, the precise contribution of these systems, particularly in varied training modalities such as single (SMT) and intermittent (IST) forms of the 30-second Wingate test, remains inadequately explored. This study aims at comparing performance outputs, physiological responses and gender differences during the SMT and IST forms of the 30-second Wingate test. Thirty-three highly trained combat sports athletes (17 women, 16 men; 10 boxing, 8 wrestling, 8 taekwondo and 7 karate) randomly performed SMT and IST. The IST consisted of three 10-second all-out attempts separated by 30 seconds of passive recovery, whereas the SMT was a single 30-second maximal effort. Resting, exercise and post-exercise oxygen uptake and peak blood lactate value were used to determine the metabolic energy demands via the PCr-LA-O2 method. The findings showed that total metabolic energy expenditure (TEE), ATP-PCr system contribution and the output of mechanical variables were higher in the IST than in the SMT form (all p<0.001). In contrast, the contribution of glycolytic and oxidative systems was higher in the SMT form (all p<0.001). However, exercise form and gender interaction were not significant (p>0.05). In combat sports, performance is not only determined by physiological and technical skills but also by metabolic energy input and efficiency. Therefore, our results can provide a comparison regarding the effects of exercise type and gender on metabolic energy metabolism to design the training of combat sports athletes.

24-h energy expenditure in people with type 1 diabetes: impact on equations for clinical estimation of energy expenditure

BACKGROUND/OBJECTIVES

Type 1 diabetes (T1D) is associated with an increase in resting metabolic rate (RMR), but the impact of T1D on other components of 24-h energy expenditure (24-h EE) is not known. Also, there is a lack of equations to estimate 24-h EE in patients with T1D. The aims of this analysis were to compare 24-h EE and its components in young adults with T1D and healthy controls across the spectrum of body mass index (BMI) and derive T1D-specific equations from clinical variables.

SUBJECTS/METHODS

Thirty-three young adults with T1D diagnosed ≥1 year prior and 33 healthy controls matched for sex, age and BMI were included in this analysis. We measured 24-h EE inside a whole room indirect calorimeter (WRIC) and body composition with dual x-ray absorptiometry.

RESULTS

Participants with T1D had significantly higher 24-h EE than healthy controls (T1D = 2047 ± 23 kcal/day vs control= 1908 ± 23 kcal/day; P < 0.01). We derived equations to estimate 24-h EE with both body composition (fat free mass + fat mass) and anthropometric (weight + height) models, which provided high coefficients of determination (R2 = 0.912 for both). A clinical model that did not incorporate spontaneous physical activity yielded high coefficients of determination as well (R2 = 0.897 and R2 = 0.880 for body composition and anthropometric models, respectively).

CONCLUSION

These results confirm that young adults with established T1D have increased 24-h EE relative to controls without T1D. The derived equations from clinically available variables can assist clinicians with energy prescriptions for weight management in patients with T1D.

Metabolic Effects of Reduced Volume Sprint Interval Training During and Postexercise

McCarthy, SF, McKie, GL, Howe, GJ, Vanderheyden, LW, and Hazell, TJ. Metabolic effects of reduced volume sprint interval training during and postexercise. J Strength Cond Res 38(5): 891–897, 2024—It is unclear what dose of sprint-interval training exercise (exercise volume) is required to derive beneficial metabolic effects during and postexercise. Therefore, we examined how reducing the volume of sprint interval training (SIT) from 2 minutes of “all-out” efforts (8 bouts) to 1.5 minutes (6 bouts) and 1 minute (4 bouts) affected during and postexercise metabolism. Fourteen recreationally active males (age: 25 ± 3 years; body mass index: 25.1 ± 3.1 kg·m−2) had gas exchange measured during and following (3 h) 4 experimental sessions: (a) no-exercise control (CTRL), (b) 8 × 15 SIT (2 minutes exercise), (c) 6 × 15 minutes SIT (1.5 minutes exercise), and (d) 4 × 15 SIT (1 minute exercise). All SIT protocols were 15 seconds “all-out” running efforts with 2 minutes recovery (4, 6, or 8 bouts). Changes were considered important if p < 0.100 and the effect size was ≥medium. During exercise, oxygen consumption (V̇o 2; L) was different between protocols (p < 0.001, d > 2.98) and greater than CTRL (p < 0.001, d > 2.12); however, the rate of O2 consumption (L·min−1) was similar between protocols (p = 0.479, = 0.055). Total V̇o 2 (L) postexercise was elevated following all conditions compared with CTRL (p < 0.003, d > 1.25). Overall session V̇o 2 was different in each condition (p < 0.001, d > 1.89). Fat oxidation was elevated postexercise following all SIT protocols compared with CTRL (p < 0.017, d > 0.98) with no differences between protocols (p > 0.566, d < 0.48). Our results suggest reducing the number of all-out 15 seconds bouts during a SIT session from 8 to 6 or 4 had no differential effects on postexercise metabolism and differences during exercise were due to the longer duration of exercise.

Acute interval running induces greater excess post-exercise oxygen consumption and lipid oxidation than isocaloric continuous running in men with obesity

Studies seem to show that high-intensity interval training (HIIT) is a more time-efficient protocol for weight loss, compared with moderate-intensity continuous training (MICT). Our aim was to compare the acute effects of energy expenditure (EE) matched HIIT vs. MICT on excess post-exercise oxygen consumption (EPOC) and substrate metabolism in male college students with obesity. Twenty-one untrained male college students (age, 22 ± 3 years; body fat, 28.4 ± 4.5%) completed two acute interventions (~ 300 kcal) on a treadmill in a randomized order: (1) HIIT: 3 min bouts at 90% of maximal oxygen uptake (VO2max) with 2 min of recovery at 25% of VO2max; (2) MICT: 60% of VO2max continuous training. EPOC and substrate metabolism were measured by indirect calorimetry during and 30 min after exercise. Results showed that EPOC was higher after HIIT (66.20 ± 14.36 kcal) compared to MICT (53.91 ± 12.63 kcal, p = 0.045), especially in the first 10 min after exercise (HIIT: 45.91 ± 9.64 kcal and MICT: 34.39 ± 7.22 kcal, p = 0.041). Lipid oxidation rate was higher after HIIT (1.01 ± 0.43 mg/kg/min) compared to MICT (0.76 ± 0.46 mg/kg/min, p = 0.003). Moreover, the percentage of energy from lipid was higher after HIIT (37.94 ± 14.21%) compared to MICT (30.09 ± 13.54%, p = 0.020). We conclude that HIIT results in greater total EE and EPOC, as well as higher percentage of energy from lipid during EPOC than EE matched MICT in male college students with obesity.

Intense interval exercise induces greater changes in post-exercise metabolism compared to submaximal exercise in middle-aged adults

INTRODUCTION

High-intensity interval training (HIIT) and sprint interval training (SIT) consistently elevate post-exercise metabolism compared to moderate-intensity continuous training (MICT) in young adults (18-25 years), however few studies have investigated this in middle-aged adults.

PURPOSE

To assess the effect of exercise intensity on post-exercise metabolism following submaximal, near-maximal, and supramaximal exercise protocols in middle-aged adults.

METHODS

12 participants (8 females; age: 44 ± 10 years; V ˙ O2max: 35.73 ± 9.97 mL·kg-1 min-1) had their oxygen consumption ( V ˙ O2) measured during and for 2 h following 4 experimental sessions: (1) no-exercise control (CTRL); (2) MICT exercise (30 min at 65% V ˙ O2max); (3) HIIT exercise (10 × 1 min at 90% maximum heart rate with 1 min rest); and (4) modified-SIT exercise (8 × 15 s "all-out" efforts with 2 min rest). Between session differences for V ˙ O2 and fat oxidation were compared.

RESULTS

O2 consumed post-exercise was elevated during the 1st h and 2nd h following HIIT (15.9 ± 2.6, 14.7 ± 2.3 L; P < 0.036, d > 0.98) and modified-SIT exercise (16.9 ± 3.3, 15.30 ± 3.4 L; P < 0.041, d > 0.96) compared to CTRL (13.3 ± 1.9, 12.0 ± 2.5 L) while modified-SIT was also elevated vs HIIT in the 1st h (P < 0.041, d > 0.96). Total post-exercise O2 consumption was elevated following all exercise sessions (MICT: 27.7 ± 4.1, HIIT: 30.6 ± 4.8, SIT: 32.2 ± 6.6 L; P < 0.027, d > 1.03) compared to CTRL (24.9 ± 4.1 L). Modified-SIT exercise increased fat oxidation (0.103 ± 0.019 g min-1) compared to all sessions post-exercise (CTRL: 0.059 ± 0.025, MICT: 0.075 ± 0.022, HIIT: 0.081 ± 0.021 g·min-1; P < 0.007, d > 1.30) and HIIT exercise increased compared to CTRL (P = 0.046, d = 0.87).

CONCLUSION

Exercise intensity has an important effect on post-exercise metabolism in middle-aged adults.

Effects of Isocaloric Resistance, Aerobic, and Concurrent Exercise on Excess Postexercise Oxygen Consumption in Older Adults

ABSTRACT

Pilon, R, Matos-Santos, L, Matlez, MP, Rodrigues, G, Amorim, F, Lattari, E, Farinatti, P, and Monteiro, W. Effects of isocaloric resistance, aerobic, and concurrent exercise on excess postexercise oxygen consumption in older adults. J Strength Cond Res 38(4): 755-761, 2024-Excess postexercise oxygen consumption (EPOC) is a major determinant of exercise-related caloric expenditure and metabolic adaptations. Exercise modality may influence the EPOC, but this issue has not been investigated in older adults. This study compared the EPOC after isocaloric bouts of continuous aerobic exercise (AE), resistance exercise (RE), and concurrent exercise (CE) in older individuals. Ten subjects (5 men; 73 ± 6 years) had their cardiorespiratory data assessed during AE, RE, and CE and along 30-minute postexercise recovery. Total energy expenditure (EE) during exercise was similar (p > 0.05) in AE (126.0 ± 30.7 kcal), RE (123.9 ± 30.6 kcal), and CE (130.8 ± 32.6 kcal), with different times to achieve the targeted EE (RE: 61.4 ± 1.9 minutes > CE: 43.3 ± 5.6 minutes > AE: 26.6 ± 5.7 minutes; p < 0.001). Consistently, the relative intensity during exercise was superior (p < 0.05) in AE (74 ± 15% oxygen uptake reserve [VO2R]) vs. CE (43 ± 13% VO2R) vs. RE (24 ± 9% VO2R). Despite the isocaloric conditions, average EPOC and EE were approximately 45% greater (p < 0.001) in AE (8.0 ± 2.3 L; 40.1 ± 11.7 kcal) vs. RE (5.6 ± 1.2 L; 28.1 ± 5.8 kcal) and CE (5.4 ± 2.3 L; 26.9 ± 11.5 kcal). In conclusion, the EPOC was greater after isocaloric AE vs. RE and CE performed by older adults. Exercise intensity seemed to be a more important determinant of EPOC than volume reflected by EE during exercise bouts. Moderate-intensity continuous AE was more time-efficient than RE and CE to achieve a target EE. In older individuals, AE should be preferred over RE or CE when the purpose is to increase the daily caloric expenditure.

Postprandial energy metabolism is modulated in response to a low-intensity walking exercise in fasted healthy individuals

Postprandial metabolism is a relevant indicator of overall metabolic health, which can be influenced by a single bout of exercise before food consumption. The present study examined the effects of an acute, fasted, low-intensity exercise on postprandial metabolism and appetite sensations. We hypothesized that exercise would induce an increase in postprandial fat oxidation, associated with better satiety responses. Twenty-two healthy adults (16 females) attended the laboratory twice separated by a minimum of 3 days to perform 2 conditions: (1) a control condition and (2) an exercise condition (EX) with a 30-minute low-intensity walking exercise performed before the breakfast (500-kcal fixed meal). Subjective appetite sensations were assessed before and up to 60 minutes after the meal in regular intervals. Energy expenditure and substrate oxidation were measured until 2 hours after the meal. Energy expenditure and carbohydrate oxidation were higher in the EX condition (condition effect: P < .01). There was no effect of exercise on appetite sensations and overall fat oxidation, but a higher increase in relative and absolute fat oxidation was observed from 15- to 45-minutes postmeal in EX compared with control (time × condition interaction effect: P < .05). In the EX condition only, postprandial satiety was associated positively with postprandial fat oxidation and negatively with carbohydrate oxidation. To conclude, a fasted low-intensity exercise induced an enhancement of postprandial metabolic flexibility through the modulation of fat oxidation. Substrate oxidation appeared to be related to satiety only after exercise, suggesting a specific regulation of appetite induced by exercise.

Excess Postexercise Oxygen Consumption Following Isocaloric Bouts of Resistance and Aerobic Exercise in Older Adults

Purpose: Albeit being a major determinant of exercise-related energy expenditure (EE), there is a lack of research on the excess post-exercise oxygen consumption (EPOC) after different exercise modalities in older adults. This study compared the EPOC after isocaloric bouts of resistance (RE) and aerobic (AE) exercise. Methods: The EE during exercise was determined through telemetric indirect calorimetry in ten physically active participants aged 63 to 82 years (5 women, 73 ± 6 years, 70.5 ± 9.9 kg, 161 ± 8 cm). The target EE in AE corresponded to values achieved during RE, and the EPOC was assessed for 30 min in the supine position. Results: The EE during AE and RE were 126.0 ± 30.7 kcal and 123.9 ± 30.6 kcal, respectively. The time to achieve the target EE was 2.3 times shorter in AE vs. RE. The EPOC magnitude was greater after AE (7.9 ± 2.4 L, 40.1 ± 11.1 kcal) than RE (5.9 ± 1.8 L, 26.9 ± 11.5 kcal). Conclusion: Older adults showed greater EPOC after isocaloric sessions of AE vs. RE. Additionally, AE had better temporal efficiency than RE to elicit a given EE.

Energy conservation by collective movement in schooling fish

Many animals moving through fluids exhibit highly coordinated group movement that is thought to reduce the cost of locomotion. However, direct energetic measurements demonstrating the energy-saving benefits of fluid-mediated collective movements remain elusive. By characterizing both aerobic and anaerobic metabolic energy contributions in schools of giant danio (Devario aequipinnatus), we discovered that fish schools have a concave upward shaped metabolism-speed curve, with a minimum metabolic cost at ~1 body length s-1. We demonstrate that fish schools reduce total energy expenditure (TEE) per tail beat by up to 56% compared to solitary fish. When reaching their maximum sustained swimming speed, fish swimming in schools had a 44% higher maximum aerobic performance and used 65% less non-aerobic energy compared to solitary individuals, which lowered the TEE and total cost of transport by up to 53%, near the lowest recorded for any aquatic organism. Fish in schools also recovered from exercise 43% faster than solitary fish. The non-aerobic energetic savings that occur when fish in schools actively swim at high speed can considerably improve both peak and repeated performance which is likely to be beneficial for evading predators. These energetic savings may underlie the prevalence of coordinated group locomotion in fishes.

Intravoxel incoherent motion imaging to assess the acute effects of moderate-intensity continuous training and high-intensity interval training on thigh muscles

This study investigated the use of intravoxel incoherent motion imaging (IVIM) to compare skeletal muscle perfusion during and after high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) to determine the impact on fat oxidation outcomes. Twenty overweight volunteers were recruited for the study. Each participant received one HIIT intervention and one MICT intervention using a cycling ergometer. Participants underwent a magnetic resonance imaging scan before, immediately after, and 1 and 2 h after each intervention. The IVIM parameters (D, fD*) of the rectus femoris, vastus lateralis, and biceps femoris long head were obtained. Changes in IVIM parameters of these muscles after both exercise interventions were compared using a two-factor repeated measures analysis of variance. In the rectus femoris, the fD* increased immediately after exercise intervention (d = 0.69 × 10-3  mm2 /s, p < 0.0083) and 2 h after exercise intervention (d = 0.64 × 10-3  mm2 /s, p < 0.0083) compared with before exercise. The increase in the fD* in the HIIT group was greater than that in the MICT group (d = 0.32, p = 0.023). In the vastus lateralis, the fD* increased immediately after the exercise intervention (d = 0.53 × 10-3  mm2 /s, p < 0.001) and returned to the pre-exercise level 1 h after exercising. The increase in the fD* in the HIIT group was lower than that in the MICT group (d = -0.21, p = 0.015). For the biceps femoris long head, the fD* was not significantly different between the two exercise interventions before and after exercise. Furthermore, the fD* 60 min after the HIIT intervention correlated with maximal oxygen consumption (VO2max), whereas fD* immediately after the MICT intervention correlated with VO2max. In summary, IVIM parameters can be used to evaluate differences in muscle perfusion between HIIT and MICT, and show a correlation with VO2max.

Can mixed circuit training elicit the recommended exercise intensity and energy expenditure in people after stroke?

PURPOSE

To investigate whether mixed circuit training (MCT) elicits the recommended exercise intensity and energy expenditure in people after stroke, and to establish the between-day reproducibility for the percentages of heart rate reserve (%HRR), oxygen uptake reserve (%VO2R), and energy expenditure elicited during two bouts of MCT.

METHODS

Seven people aged 58 (12) yr, who previously had a stroke, performed a cardiopulmonary exercise test, a non-exercise control session, and two bouts of MCT. The MCT included 3 circuits of 10 resistance exercises at 15-repetition maximum intensity, with each set of resistance exercise interspersed with 45-s of walking. Expired gases were collected during the MCT and control session and for 40 min afterward. Control session was necessary to calculate the net energy expenditure associated with each bout of MCT.

RESULTS

Mean %VO2R (1st MCT: 51.1%, P = .037; 2nd MCT: 54.0%, P = .009) and %HRR (1st MCT: 66.4%, P = .007; 2nd MCT: 67.9%, P = .010) exceeded the recommended minimum intensity of 40%. Both %VO2R (P = .586 and 0.987, respectively) and %HRR (P = .681 and 0.237, respectively) during the 1st and 2nd bouts of MCT were not significantly different to their corresponding gas exchange threshold values derived from cardiopulmonary exercise testing. Mean net total energy expenditure significantly exceeded the minimum recommend energy expenditure in the 1st (P = .048) and 2nd (P = .023) bouts of MCT. Between-day reproducibility for %HRR, %VO2R, and energy expenditure was excellent (ICC: 0.92-0.97).

CONCLUSIONS

MCT elicited physiological strain recommended for improving health-related fitness in people after stroke and these responses demonstrated excellent between-day reproducibility.

Energetics of collective movement in vertebrates

The collective directional movement of animals occurs over both short distances and longer migrations, and is a critical aspect of feeding, reproduction and the ecology of many species. Despite the implications of collective motion for lifetime fitness, we know remarkably little about its energetics. It is commonly thought that collective animal motion saves energy: moving alone against fluid flow is expected to be more energetically expensive than moving in a group. Energetic conservation resulting from collective movement is most often inferred from kinematic metrics or from computational models. However, the direct measurement of total metabolic energy savings during collective motion compared with solitary movement over a range of speeds has yet to be documented. In particular, longer duration and higher speed collective motion must involve both aerobic and non-aerobic (high-energy phosphate stores and substrate-level phosphorylation) metabolic energy contributions, and yet no study to date has quantified both types of metabolic contribution in comparison to locomotion by solitary individuals. There are multiple challenging questions regarding the energetics of collective motion in aquatic, aerial and terrestrial environments that remain to be answered. We focus on aquatic locomotion as a model system to demonstrate that understanding the energetics and total cost of collective movement requires the integration of biomechanics, fluid dynamics and bioenergetics to unveil the hydrodynamic and physiological phenomena involved and their underlying mechanisms.

Impacto de los diferentes tipos de entrenamiento físico sobre la composición corporal en mujeres adultas con obesidad: una revisión bibliográfica

Introducción: La obesidad sigue siendo uno de los problemas más grandes de salud pública en todo el mundo. Se conoce que está asociada con una gran variedad de enfermedades; en mujeres obesas, aún se desconoce la forma idónea para realizar una adecuada prescripción física. Objetivo: revisar los tipos de entrenamientos físicos de ensayos controlados aleatorizados publicados en la base de datos PubMed entre los años 2015 a 2022 sobre los cambios en la composición corporal en mujeres adultas de 18 a 65 años con obesidad. Metodología: se utilizó a modo de filtro la “Herramienta de Evaluación de Calidad Validada para Estudios Cuantitativos”. Resultados: la búsqueda arrojó 586 artículos, de los cuales el 93.85% fueron eliminados; 6.14% pasaron por un filtro que dejó un total de 1.7%. Conclusión: en mujeres adultas con obesidad, se ha demostrado que todos los tipos de entrenamiento físico sirven para generar cambios en la composición corporal. Introduction: Obesity continues to be one of the biggest public health problems worldwide. It is known to be associated with a wide variety of diseases; in obese women, the ideal way to carry out an adequate physical prescription is still unknown. Objective: to review the types of physical training in randomized controlled trials published in the PubMed database between 2015 and 2022 on changes in body composition in adult women aged 18 to 65 with obesity. Methodology: the "Validated Quality Assessment Tool for Quantitative Studies" was used as a filter. Outcomes: the search yielded 586 articles, of which 93.85% were eliminated; 6.14% went through a filter that left a total of 1.7%. Conclusion: in adult women with obesity, it has been shown that all types of physical training serve to generate changes in body composition.

The effect of Tabata-style functional high-intensity interval training on cardiometabolic health and physical activity in female university students

Introduction: The increasing prevalence of metabolic syndrome and physical inactivity enhances exposure to cardiometabolic risk factors in university students. High-intensity interval training (HIIT) improved cardiometabolic health in clinical adults but the evidence in the university setting is limited. Furthermore, few studies examined the effect of low-volume HIIT on habitual physical activity (PA). Therefore, the primary aim of this study was to evaluate the efficacy of 12-week Tabata-style functional HIIT for improving multiple cardiometabolic health outcomes and habitual PA. We also investigated whether changes in habitual PA over the intervention period had an impact on exercise-induced health outcomes. Methods: 122 female freshmen were randomized into the Tabata group (n = 60) and the control (n = 62). The Tabata training protocol involved 8 × 20 s maximal repeated functional exercises followed by 10 s rest with a frequency of 3 times per week for 12 weeks. Body composition, maximal oxygen uptake (VO_2max), blood pressure (BP), blood lipids, fasting glucose and insulin, C-reactive protein and PA were objectively measured using standardized methods. Dietary intake was measured using a valid food frequency questionnaire. All variables were measured pre- and post-intervention. Results: Mixed linear modelling results showed that there were large intervention effects on VO_2max (p < 0.001, d = 2.53, 95% CI: 2.03 to 3.00 for relative VO_2max; p < 0.001, d = 2.24, 95% CI: 1.76 to 2.68 for absolute VO_2max), resting heart rate (p < 0.001, d = -1.82, 95% CI: -2.23 to -1.37), systolic BP (p < 0.001, d = -1.24, 95% CI: -1.63 to -0.84), moderate-to-vigorous intensity physical activity (MVPA) (p < 0.001, d = 2.31, 95% CI: 1.83 to 2.77), total PA (p < 0.001, d = 1.98, 95% CI: 1.53 to 2.41); moderate effects on %BF (p < 0.001, d = -1.15, 95% CI: -1.53 to -0.75), FM (p < 0.001, d = -1.08, 95% CI: -1.46 to -0.69), high-density lipoprotein (HDL) (p < 0.001, d = 1.04, 95% CI: 0.65 to 1.42), total cholesterol (p = 0.001, d = -0.64, 95% CI: -1.00 to -0.26); small effects on BMI (p = 0.011, d = -0.48, 95% CI: -0.84 to 0.11), WC (p = 0.043, d = -0.37, 95% CI: -0.74 to -0.01), low-density lipoprotein (p = 0.003, d = -0.57, 95% CI: -0.93 to -0.19), HOMA-IR (p = 0.026, d = -0.42, 95% CI: -0.78 to -0.05) and fasting insulin (p = 0.035, d = -0.40, 95% CI: -0.76 to -0.03). Regression analysis showed that only the percentage change of HDL was associated with the change of MVPA (b = 0.326, p = 0.015) and TPA (b = 0.480, p = 0.001). Conclusion: From the findings of the study we can conclude that 12-week low-volume Tabata-style functional HIIT was highly effective for university female students to improve cardiorespiratory fitness, body fat, some cardiometabolic health outcomes and habitual PA.

Sex-Related Differences in Oxygen Consumption Recovery After High-Intensity Rowing Exercise During Childhood and Adolescence

PURPOSE

To determine sex-related differences in oxygen consumption (V˙O2) recovery after high-intensity exercise during childhood and adolescence.

METHODS

Forty-two boys and 35 girls (10-17 y) performed a 60-second all-out test on a rowing ergometer. Postexercise V˙O2 recovery was analyzed from (1) the V˙O2 recovery time constant obtained from a biexponential model (τ1V˙O2) and (2) excess postexercise oxygen consumption calculated over a period of 8 minutes (EPOC8) and until τ1V˙O2 was reached (EPOCτ1). Multiplicative allometric modeling was used to assess the concurrent effects of body mass or lean body mass, and age on EPOC8 and EPOCτ1.

RESULTS

EPOC8 increased significantly more in boys from the age of 14 years. However, the sex difference was no longer significant when EPOC8 was analyzed using an allometric model including body mass + age or lean body mass + age. In addition, despite a greater increase in EPOCτ1 in boys from the age of 14 years, τ1V˙O2 was not significantly different between sexes whatever age.

CONCLUSION

While age and lean body mass accounted for the sex-related differences of EPOC during childhood and adolescence, no significant effect of age and sex was observed on the V˙O2 recovery time constant after high-intensity exercise.

The effects of high-intensity interval training and moderate-intensity continuous training on visceral fat and carotid hemodynamics parameters in obese adults

Objectives

The present study aimed to examine the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on visceral fat and hemodynamic parameters in obese adults.

Methods

Fifty-two males were included in this study and divided into three groups: HIIT group (n = 21, age = 20.86 ± 1.62 years, BF (%) = 30.10 ± 5.02), MICT group (n = 22, age = 20.76 ± 1.14 years, BF (%) = 30.19 ± 5.76), and control group (CON) (n = 9, age = 21.38 ± 1.77 years, BF (%) = 30.40 ± 5.10). The HIIT and MICT groups received the exercise intervention three to four times per week for eight weeks (HIIT: exercise intensity 80–95% HRmax, circuit; MICT: exercise intensity 60–70% HRmax, running), and the control (CON) group received health education and guidance without exercise intervention. The body compositions and serum lipid indexes were tested to calculated LAP and VAI. The color doppler ultrasound diagnostic technology was used to test the artery diameter and blood velocity before and after the intervention. Based on the test data, MATLAB software and Womersley theory were used to calculate the hemodynamic parameters of the common carotid artery, including wall shear stress, flow rate, blood pressure, oscillatory shear index, elasticity modulus, dynamic resistance, artery diameter, arterial stiffness, circumferential strain and pulsatility index.

Results

We found that lipid accumulation product (LAP) was significantly decreased in both the HIIT group (p < 0.01) and MICT (p < 0.05) group but not in the CON group (p > 0.05). In contrast, visceral adiposity index (VAI) decreased in both the HIIT and MICT groups and increased in the CON group, although the difference among groups was not significant (p > 0.05). After 8 weeks of intervention, the blood velocity and wall shear stress were greater after HIIT and MICT intervention (p < 0.01). Artery diameter, oscillatory shear index, arterial stiffness, and pulsatility index decreased significantly, and circumferential strain increased significantly in the HIIT group (all, p < 0.01, p < 0.05) but not in the MICT group (p > 0.05). Dynamic resistance was significantly decreased in the MICT group. There was no difference in the CON group after the period of intervention (all, p > 0.05). LAP was positively related to artery diameter (r = 0.48, p = 0.011), blood pressure (r = 0.46, p = 0.002), flow rate (r = 0.31, p = 0.04), oscillatory shear index (r = 0.44, p = 0.03), and elasticity modulus (r = 0.33, p = 0.029) but inversely related to circumferential strain (r = −0.36, p = 0.028). The VAI was also positively associated with artery diameter (r = 0.33, p = 0.03), elasticity modulus (r = 0.38, p = 0.009), and arterial stiffness (r = 0.39, p = 0.012). In addition, the VAI was negatively correlated with the circumferential strain (r = −0.33, p = 0.04).

Conclusion

The present study demonstrated that both HIIT and MICT exercises for 8 weeks could effectively enhance visceral fat indices and partial hemodynamic parameters. Therefore, HIIT and MICT exert important effects on reducing fat content and improving hemodynamic environment. But HIIT on oscillatory shear index, arterial stiffness, circumferential strain, and pulsatility index was superior to MICT. In addition, there are close correlations between visceral fat and partial hemodynamic parameters of the common carotid artery.

Different Exercise Types Produce the Same Acute Inhibitory Control Improvements When the Subjective Intensity Is Equal

Twenty-eight active older people (67.19 ± 4.91 years) who engaged in physical exercise activity twice a week were recruited to participate in a counterbalanced experimental protocol. The participants performed three different exercise sessions on three different days, one based on aerobic activities, one based on strength exercises with elastic bands, and one based on stationary balance games. During all three sessions, they were encouraged to maintain a moderate subjective intensity (5-6 on the RPE10 scale), and their heart rate was recorded. In addition, all of the participants took a digital version of the Stroop test before and after each session. The study aimed to compare the acute cognitive impacts of different types of exercise sessions in older adults. The participants' heart rate differed between the exercise sessions, but they maintained the RPE intensity. There was a significant improvement in inhibitory control (Stroop test) after all sessions, with no differences between exercise sessions. Moreover, some participants agreed to be genotyped to record the single nucleotide polymorphism of BDNF rs6265. There were no differences between Val/Val and Met carriers at the beginning or end of the exercise sessions. The present study showed similar cognitive improvements with different exercise type sessions when the subjective intensity was maintained.

Exercise Dose Equalization in High-Intensity Interval Training: A Scoping Review

Based on comparisons to moderate continuous exercise (MICT), high-intensity interval training (HIIT) is becoming a worldwide trend in physical exercise. This raises methodological questions related to equalization of exercise dose when comparing protocols. The present scoping review aims to identify in the literature the evidence for protocol equalization and the soundness of methods used for it. PubMed and Scopus databases were searched for original investigations comparing the effects of HIIT to MICT. A total of 2041 articles were identified, and 169 were included. Of these, 98 articles equalized protocols by utilizing energy-based methods or exercise volume (58 and 31 articles, respectively). No clear consensus for protocol equalization appears to have evolved over recent years. Prominent equalization methods consider the exercise dose (i.e., energy expenditure/production or total volume) in absolute values without considering the nonlinear nature of its relationship with duration. Exercises resulting from these methods induced maximal exertion in HIIT but low exertion in MICT. A key question is, therefore, whether exercise doses are best considered in absolute terms or relative to individual exercise maximums. If protocol equalization is accepted as an essential methodological prerequisite, it is hypothesized that comparison of program effects would be more accurate if exercise was quantified relative to intensity-related maximums.

Effects of Resistance Training on Skin Temperature and Its Relationship with Central Nervous System (CNS) Activation

The aim of this work was to relate the activation of the sympathetic and parasympathetic nervous systems with the skin temperature (Tsk) of the lower limbs after a resistance training exercise. Under controlled conditions, the average Tsk in the areas of the anterior and posterior thighs, knees and legs was obtained with a thermal imager and the parasympathetic and sympathetic activation was registered with an Omegawave^® device on 20 healthy and trained male volunteers (25.39 ± 8.21 years) before exercise, immediately after standard resistance training (3 exercises (2 quadriceps + 1 hamstrings) × 4 sets × 10 repetitions (70% 1RM), 90-sec recovery) and after 20 min of recovery. The results showed a significant effect of exercise and recovery on Tsk in all regions of interest (ROIs) considered (p < 0.05) and strong inverse relationships between sympathetic and parasympathetic activation values. Significant results were found for the total variation of Tsk (p < 0.05) with highly positive values for subjects with lower sympathetic activation and almost null or even negative values for those with higher sympathetic activation. Sympathetic activity was a significant predictor of total Tsk variation in the anterior thigh, posterior thigh and anterior knee but not in the posterior knee, anterior leg, and posterior leg. Baseline Tsk was a significant predictor of total Tsk variation the all ROIs except in the posterior knee. Tsk measured by thermography could be used to estimate the level of participation of muscle areas in exercise and registering the level of sympathetic activation before exercise could be interesting in predicting the athlete’s physiological response to strength training.

Effects of High-Intensity Interval Training and Moderate-Intensity Continuous Training on Cardiometabolic Risk Factors in Overweight and Obesity Children and Adolescents: A Meta-Analysis of Randomized Controlled Trials

Background: The purpose of this review was to compare the effectiveness of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on cardiometabolic risk factors of obese children and adolescents. Methods: Relevant studies published in PubMed, MEDLINE and Web of Science databases were searched. Only randomized controlled trials (RCTs) that examined the effect of HIIT and MICT on children and adolescents with obesity were included. Meta-analyses were conducted to determine the effect of HIIT on cardiometabolic risk factors using STATA software and potential moderators were explored (i.e., study duration, training modalities, work/rest ratio and work duration time). Results: Twelve RCTs involving 325 participants were included in the meta-analysis. HIIT showed more positive effects on maximal oxygen uptake (VO_2max; SMD = 0.87, 95% CI: 0.39 to 1.35, p = 0.000) and systolic blood pressure (SBP; SMD = −0.64, 95% CI: −1.05 to −0.22, p = 0.003) than MICT. However, when compared with MICT, HIIT caused no significant differences in body weight, body mass index, body fat percentage, diastolic blood pressure and glycolipid metabolism markers. Furthermore, subgroup analysis showed that the effects of HIIT on VO_2max and SBP were significantly different regarding protocol factors, such as modality, duration, training time, training settings, work/rest ratio and work duration. Conclusions: HIIT has a positive role in promoting cardiometabolic risk factors in obese children and adolescents. Moreover, when compared with MICT, HIIT had a more significant effect on improving cardiorespiratory fitness and systolic blood pressure. The factors of HIIT protocol had an important influence on the intervention effects of childhood obesity.

The Effect of Resistance Training in Healthy Adults on Body Fat Percentage, Fat Mass and Visceral Fat: A Systematic Review and Meta-Analysis

BACKGROUND

Resistance training is the gold standard exercise mode for accrual of lean muscle mass, but the isolated effect of resistance training on body fat is unknown.

OBJECTIVES

This systematic review and meta-analysis evaluated resistance training for body composition outcomes in healthy adults. Our primary outcome was body fat percentage; secondary outcomes were body fat mass and visceral fat.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

We searched five electronic databases up to January 2021.

ELIGIBILITY CRITERIA

We included randomised trials that compared full-body resistance training for at least 4 weeks to no-exercise control in healthy adults.

ANALYSIS

We assessed study quality with the TESTEX tool and conducted a random-effects meta-analysis, with a subgroup analysis based on measurement type (scan or non-scan) and sex (male or female), and a meta-regression for volume of resistance training and training components.

RESULTS

From 11,981 records, we included 58 studies in the review, with 54 providing data for a meta-analysis. Mean study quality was 9/15 (range 6-15). Compared to the control, resistance training reduced body fat percentage by - 1.46% (95% confidence interval - 1.78 to - 1.14, p < 0.0001), body fat mass by - 0.55 kg (95% confidence interval - 0.75 to - 0.34, p < 0.0001) and visceral fat by a standardised mean difference of - 0.49 (95% confidence interval - 0.87 to - 0.11, p = 0.0114). Measurement type was a significant moderator in body fat percentage and body fat mass, but sex was not. Training volume and training components were not associated with effect size. Resistance training reduces body fat percentage, body fat mass and visceral fat in healthy adults.

STUDY REGISTRATION

osf.io/hsk32.

The Mystery of Energy Compensation

AbstractThe received wisdom on how activity affects energy expenditure is that the more activity is undertaken, the more calories will have been burned by the end of the day. Yet traditional hunter-gatherers, who lead physically hard lives, burn no more calories each day than Western populations living in labor-saving environments. Indeed, there is now a wealth of data, both for humans and other animals, demonstrating that long-term lifestyle changes involving increases in exercise or other physical activities do not result in commensurate increases in daily energy expenditure (DEE). This is because humans and other animals exhibit a degree of energy compensation at the organismal level, ameliorating some of the increases in DEE that would occur from the increased activity by decreasing the energy expended on other biological processes. And energy compensation can be sizable, reaching many hundreds of calories in humans. But the processes that are downregulated in the long-term to achieve energy compensation are far from clear, particularly in humans-we do not know how energy compensation is achieved. My review here of the literature on relevant exercise intervention studies, for both humans and other species, indicates conflict regarding the role, if any, of basal metabolic rate (BMR) or low-level activity such as fidgeting play, particularly once changes in body composition are factored out. In situations where BMR and low-level activity are not major components of energy compensation, what then drives it? I discuss how changes in mitochondrial efficiency and changes in circadian fluctuations in BMR may contribute to our understanding of energy management. Currently unexplored, these mechanisms and others may provide important insights into the mystery of how energy compensation is achieved.

Are all MVPA minutes equal? Associations between MVPA characteristics, independent of duration, and childhood adiposity

BACKGROUND

The inverse relationship between moderate-to-vigorous physical activity (MVPA) duration and childhood adiposity is well established. Less is known about how characteristics of MVPA accumulation may be associated with adiposity, independent of MVPA duration. This study aimed to investigate how the MVPA characteristics of children, other than duration (bout length, time of day, day-to-day consistency, intensity), were associated with adiposity.

METHODS

Cross-sectional study of the Australian arm of the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) (participants: n = 424, age range 9-11, 44% male). Adiposity was determined by percent body fat via bioelectrical impedance. MVPA duration and characteristics (bout length, time of day, consistency, intensity) were derived from 7-day, 24-h accelerometry. Generalised estimating equations were used to examine the individual and multivariate associations between MVPA characteristics and adiposity.

RESULTS

Univariate analyses showed that higher MVPA duration (β range = - 0.26,-0.15), longer bouts of MVPA (β range = 0.15,0.22) and higher MVPA intensity (β range = - 0.20,-0.13) were all inversely associated with adiposity (all p < 0.05). When models were adjusted for MVPA duration, only MVPA intensity (β range = - 0.16,-0.04) showed consistent significant associations with adiposity.

CONCLUSIONS

Characteristics of MVPA other than duration and intensity appear to be unrelated to adiposity.

The effects of breaking sedentary time with different intensity exercise bouts on energy metabolism: A randomized cross-over controlled trial

BACKGROUND AND AIMS

Breaking up sedentary periods, particularly with light activity, increases total energy expenditure (EE), and helps provide better glycemic control. However, the effects of activities of various intensities to interrupt prolonged sedentary time are unclear. The purpose of the present study was to examine potential differences in glycemic control and EE from breaking up sedentary time with short exercise bouts of different intensities.

METHODS AND RESULTS

Nine overweight/obesity young men underwent whole body indirect calorimetry at 19:00 on day 1 and stayed overnight. After awakening on day 2, they performed short duration jogging every 30 min over 8 h (16-time bouts in total) under 3 different conditions with the same running distance: (1) lactate threshold (LT) for 2 min, (2) 60% LT for 200 s, and (3) onset of blood lactate accumulation (OBLA) for 75 s. The 24-h EE and interstitial glucose concentration (from 8:00 to 19:00 on day 2) was continuously measured throughout the trials. The standard deviation during intervention and indexes of postprandial of the interstitial glucose concentration was significantly lower at LT and OBLA than at 60% LT (p < 0.05). The 24-h EE was not significantly different among conditions, but EE at OBLA during intervention was slightly but significantly higher than at 60% LT and LT.

CONCLUSION

Breaking up sedentary time with short-duration jogging at LT and with OBLA intensities may have better glycemic control and increased use of carbohydrate as a fuel, while short-duration a jogging at OBLA intensity may increase EE.

TRIAL REGISTRATION

UMIN000041361.

The Impact of Low Energy Availability on Nonexercise Activity Thermogenesis and Physical Activity Behavior in Recreationally Trained Adults

Energy availability describes the amount of dietary energy remaining for physiological functionality after the energy cost of exercise is deducted. The physiological and hormonal consequences of low energy availability (LEA) are well established, but the impact of LEA on physical activity behavior outside of exercise and, specifically, nonexercise activity thermogenesis (NEAT) has not been systematically examined. The authors conducted a secondary analysis of a repeated-measures crossover study in which recreationally trained young men (n = 6, 25 ± 1.0 years) underwent two 4-day conditions of LEA (15 kcal·kg fat-free mass-1 ·day-1) with and without endurance exercise (LEA + EX and LEA EX) and two energy-balanced control conditions (CON + EX and CON EX). The duration and intensity of physical activity outside of prescribed exercise were assessed using the SenseWear Pro3 armband. LEA did not alter NEAT (p = .41), nor time spent in moderate to vigorous (p = .20) and low-intensity physical activity (p = .17). However, time spent in low-intensity physical activity was lower in LEA + EX than LEA - EX (13.7 ± 0.3 vs. 15.2 ± 0.3 hr/day; p = .002). Short-term LEA does not seem to impact NEAT per se, but the way it is attained may impact physical activity behavior outside of exercise. As the participants expended similar amounts of energy during NEAT (900-1,300 kcal/day = 12.5-18.0 kcal·kg fat-free mass-1·day-1) and prescribed exercise bouts (15.0 kcal·kg fat-free mass-1·day-1), excluding it as a component of energy expenditure may skew the true energy available for physiological functionality in active populations.

Estimating excess post-exercise oxygen consumption using multiple linear regression in healthy Korean adults: a pilot study

Purpose

This pilot study aimed to develop a regression model to estimate the excess post-exercise oxygen consumption (EPOC) of Korean adults using various easy-to-measure dependent variables.

Methods

The EPOC and dependent variables for its estimation (e.g., sex, age, height, weight, body mass index, fat-free mass [FFM], fat mass, % body fat, and heart rate_sum [HR_sum]) were measured in 75 healthy adults ( 31 males, 44 females). Statistical analysis was performed to develop an EPOC estimation regression model using the stepwise regression method.

Results

We confirmed that FFM and HR_sum were important variables in the EPOC regression models of various exercise types. The explanatory power and standard errors of estimates (SEE) for EPOC of each exercise type were as follows: the continuous exercise (CEx) regression model was 86.3% (R2) and 85.9% (adjusted R2), and the mean SEE was 11.73 kcal, interval exercise (IEx) regression model was 83.1% (R2) and 82.6% (adjusted R2), while the mean SEE was 13.68 kcal, and the accumulation of short-duration exercise (AEx) regression models was 91.3% (R2) and 91.0% (adjusted R2), while the mean SEE was 27.71 kcal. There was no significant difference between the measured EPOC using a metabolic gas analyzer and the predicted EPOC for each exercise type.

Conclusion

This pilot study developed a regression model to estimate EPOC in healthy Korean adults. The regression model was as follows: CEx = -37.128 + 1.003 × (FFM) + 0.016 × (HR_sum), IEx = -49.265 + 1.442 × (FFM) + 0.013 × (HR_sum), and AEx = -100.942 + 2.209 × (FFM) + 0.020 × (HR_sum).

Effects of Two Workload-Matched High-Intensity Interval Training Protocols on Regional Body Composition and Fat Oxidation in Obese Men

The effects of two high-intensity interval training (HIIT) protocols on regional body composition and fat oxidation in men with obesity were compared using a parallel randomized design. Sixteen inactive males (age, 38.9 ± 7.3 years; body fat, 31.8 ± 3.9%; peak oxygen uptake, VO_2peak, 30.9 ± 4.1 mL/kg/min; all mean ± SD) were randomly assigned to either HIIT10 (48 × 10 s bouts at 100% of peak power [W_peak] with 15 s of recovery) or HIIT60 group (8 × 60 s bouts at 100% W_peak with 90 s of recovery), and subsequently completed eight weeks of training, while maintaining the same diet. Analyses of variance (ANOVA) showed only a main effect of time (p < 0.01) and no group or interaction effects (p > 0.05) in the examined parameters. Total and trunk fat mass decreased by 1.81 kg (90%CI: −2.63 to −0.99 kg; p = 0.002) and 1.45 kg (90%CI: −1.95 to −0.94 kg; p < 0.001), respectively, while leg lean mass increased by 0.86 kg (90%CI: 0.63 to 1.08 kg; p < 0.001), following both HIIT protocols. HIIT increased peak fat oxidation (PFO) (from 0.20 ± 0.05 to 0.33 ± 0.08 g/min, p = 0.001), as well as fat oxidation over a wide range of submaximal exercise intensities, and shifted PFO to higher intensity (from 33.6 ± 4.6 to 37.6 ± 6.7% VO_2peak, p = 0.039). HIIT, irrespective of protocol, improved VO_2peak by 20.0 ± 7.2% (p < 0.001), while blood lactate at various submaximal intensities decreased by 20.6% (p = 0.001). In conclusion, both HIIT protocols were equally effective in improving regional body composition and fat oxidation during exercise in obese men.

Rapid component of excess post-exercise oxygen consumption of children of different weight status after playing active video games

BACKGROUND

Excess post-exercise oxygen consumption (EPOC) of children could indicate the potential of an exercise therapy to treat or prevent obesity. However, EPOC as a result of playing active video games (AVG) has been poorly investigated. Therefore, we aimed to investigate the rapid component of EPOC of children with healthy weight and overweight/obesity (according to their BMI percentile) after playing AVGs that feature predominately upper body (UB) and whole-body (WB) movement.

METHODS

Twenty-one children with healthy weight (BMI percentile < 85%) and with overweight/obesity (BMI percentile ≥ 85%) randomly underwent two 10-min AVG sessions (UB and WB). The heart rate (HR), minute ventilation (VE), oxygen consumption (VO2) and carbon dioxide production (VCO2) were recorded during exercise and post-exercise recovery period. For the rapid component of EPOC in each AVG session, measurements were recorded every 15 s for 5-min of post-exercise recovery. The rate of perceived exertion (RPE) was also measured immediately before and after each AVG play.

RESULTS

Children with overweight/obesity had a higher average of absolute VE, VO2, and VCO2 than their healthy-weight counterparts (BMI percentile < 85%; n = 21) during post-exercise recovery. RPE, HR, and HR% were not different between the game sessions and weight groups. Children with overweight/obesity showed a higher absolute VO2 during EPOC than healthy-weight children in both game sessions, but relative VO2 was higher in healthy-weight children during EPOC. No differences were observed for EPOC between UB and WB sessions.

CONCLUSIONS

Children with overweight/obesity had a greater EPOC than healthy-weight children after AVG sessions in terms of absolute oxygen values, whereas healthy-weight children have higher EPOC considering relative VO2 when controlling for body mass. UB and WB AVGs induced a similar EPOC among children with healthy weight and overweight/obesity. As UB and WB AVGs induce the rapid component of EPOC in children regardless their weight status, AVGs could be used as an exercise method to treat and prevent child obesity.

Can HRV Biofeedback Improve Short-Term Effort Recovery? Implications for Intermittent Load Sports

As intensity and physical demands continue to rise in sport competition, faster and better recovery becomes essential. The aim of this study was to assess the effects of HRV biofeedback (HRVB) while recovering from a submaximal aerobic exercise. Ten physically-active graduate students participated in the study, which was conducted in four sessions: exercise with free-breathing recovery, first resonance frequency (RF) detection, second RF detection, and exercise applying HRVB during recovery. Measurements included time spent running and recovering, HRV parameters, and recovery/exertion perceptions. The results indicate that using HRVB during recovery improves cardiac variability (RRmean, SDNN, RMSSD and LF; p < 0.01). HRVB also lowers recovery time (p < 0.05) and seems to be improving the perception of recovery (p = 0.087). Moreover, time spent exercising (p < 0.01) and perceived physical exertion (p < 0.05) were higher when applying HRVB. The improvement in the psychophysiological adaptation after intensive aerobic exercise provided by the HRVB is a valuable benefit, not only for competition-driven athletes, but also for the general population.

High intensity interval training exercise-induced physiological changes and their potential influence on metabolic syndrome clinical biomarkers: a meta-analysis

BACKGROUND

Despite the current debate about the effects of high intensity interval training (HIIT), HIIT elicits big morpho-physiological benefit on Metabolic Syndrome (MetS) treatment. However, no review or meta-analysis has compared the effects of HIIT to non-exercising controls in MetS variables. The aim of this study was to determine through a systematic review, the effectiveness of HIIT on MetS clinical variables in adults.

METHODS

Studies had to be randomised controlled trials, lasting at least 3 weeks, and compare the effects of HIIT on at least one of the MetS clinical variables [fasting blood glucose (BG), high-density lipoprotein (HDL-C) triglyceride (TG), systolic (SBP) or diastolic blood pressure (DBP) and waist circumference (WC)] compared to a control group. The methodological quality of the studies selected was evaluated using the PEDro scale.

RESULTS

Ten articles fulfilled the selection criteria, with a mean quality score on the PEDro scale of 6.7. Compared with controls, HIIT groups showed significant and relevant reductions in BG (- 0.11 mmol/L), SBP (- 4.44 mmHg), DBP (- 3.60 mmHg), and WC (- 2.26 cm). Otherwise, a slight increase was observed in HDL-C (+ 0.02 mmol/L). HIIT did not produce any significant changes in TG (- 1.29 mmol/L).

CONCLUSIONS

HIIT improves certain clinical aspects in people with MetS (BG, SBP, DBP and WC) compared to people with MetS who do not perform physical exercise. Plausible physiological changes of HIIT interventions might be related with large skeletal muscle mass implication, improvements in the vasomotor control, better baroreflex control, reduction of the total peripheral resistance, increases in excess post-exercise oxygen consumption, and changes in appetite and satiety mechanisms.

Underlying mechanisms of oxygen uptake kinetics in chronic post-stroke individuals: A correlational, cross-sectional pilot study

Post-stroke individuals presented deleterious changes in skeletal muscle and in the cardiovascular system, which are related to reduced oxygen uptake ([Formula: see text]) and take longer to produce energy from oxygen-dependent sources at the onset of exercise (mean response time, MTRON) and during post-exercise recovery (MRTOFF). However, to the best of our knowledge, no previous study has investigated the potential mechanisms related to [Formula: see text] kinetics response (MRTON and MRTOFF) in post-stroke populations. The main objective of this study was to determine whether the MTRON and MRTOFF are related to: 1) body composition; 2) arterial compliance; 3) endothelial function; and 4) hematological and inflammatory profiles in chronic post-stroke individuals. Data on oxygen uptake ([Formula: see text]) were collected using a portable metabolic system (Oxycon Mobile®) during the six-minute walk test (6MWT). The time to achieve 63% of [Formula: see text] during a steady state (MTRON) and recovery (MRTOFF) were analyzed by the monoexponential model and corrected by a work rate (wMRTON and wMRTOFF) during 6MWT. Correlation analyses were made using Spearman's rank correlation coefficient (rs) and the bias-corrected and accelerated bootstrap method was used to estimate the 95% confidence intervals. Twenty-four post-stroke participants who were physically inactive took part in the study. The wMRTOFF was correlated with the following: skeletal muscle mass (rs = -0.46), skeletal muscle mass index (rs = -0.45), augmentation index (rs = 0.44), augmentation index normalized to a heart rate of 75 bpm (rs = 0.64), reflection magnitude (rs = 0.43), erythrocyte (rs = -0.61), hemoglobin (rs = -0.54), hematocrit (rs = -0.52) and high-sensitivity C-reactive protein (rs = 0.58), all p < 0.05. A greater amount of oxygen uptake during post-walking recovery is partially related to lower skeletal muscle mass, greater arterial stiffness, reduced number of erythrocytes and higher systemic inflammation in post-stroke individuals.

Exercise training-induced visceral fat loss in obese women: The role of training intensity and modality

Visceral fat loss in response to four-cycle ergometer training regimens with explicit differences in exercise intensity and modality was compared. Fifty-nine obese young women (body fat percentage ≥ 30%) were randomized to a 12-week intervention consisting of either all-out sprint interval training (SIT_all-out , n = 11); supramaximal SIT (SIT₁₂₀ , 120% V ˙ O_2peak , n = 12); high-intensity interval training (HIIT₉₀ , 90% V ˙ O_2peak , n = 12), moderate-intensity continuous training (MICT, 60% V ˙ O_2peak , n = 11), or no training (CON, n = 13). The total work done per training session in SIT₁₂₀ , HIIT₉₀ , and MICT was confined to 200 kJ, while it was deliberately lower in SIT_all-out . The abdominal visceral fat area (AVFA) was measured through computed tomography scans. The whole-body and regional fat mass were assessed through dual-energy X-ray absorptiometry. Pre-, post-, and 3-hour post-exercise serum growth hormone (GH), and epinephrine (EPI) were measured during selected training sessions. Following the intervention, similar reductions in whole-body and regional fat mass were found in all intervention groups, while the reductions in AVFA resulting from SIT_all-out , SIT₁₂₀ , and HIIT₉₀ (>15 cm² ) were greater in comparison with MICT (<3.5 cm² , P < .05). The AVFA reductions among the SITs and HIIT groups were similar, and it was concomitant with the similar exercise-induced releases of serum GH and EPI. CON variables were unchanged. These findings suggest that visceral fat loss induced by interval training at or above 90% V ˙ O_2peak appeared unresponsive to the change in training intensity. Nonetheless, SIT_all-out is still the most time-efficient strategy among the four exercise-training regimes for controlling visceral obesity.

Similar Energy Expenditure During BodyPump and Heavy Load Resistance Exercise in Overweight Women

Purpose

High-repetition, low-load resistance exercise in group class settings has gained popularity in recent years, with BodyPump as a prime example. For individuals using exercise for body-weight management, the energy expenditure during exercise is of interest. Therefore, we herein aimed to estimate the energy expenditure during a session of BodyPump and a time-matched session of heavy load resistance training in overweight women (BMI ≥ 25.0).

Methods

Eighteen women participated in the study (mean age 35.4 years ± 10.2, BMI 30.4 kg/m² ± 4.8), 10 exercising BodyPump (50–100 repetitions each muscle group) and eight performed a heavy load session (eight repetition maximum × three sets). The energy expenditure was assessed with indirect calorimetry during the sessions and for two intervals at rest during the recovery phase: 0–20 and 120–140 min after the sessions.

Results

The BodyPump group lifted significantly more loads than the heavy load group (19,485 kg ± 2258 vs 15,616 kg ± 2976, p = 0.006), while energy expenditure was similar with 302 kcal ± 67 and 289 kcal ± 69 in BodyPump and heavy load group, respectively (p = 0.69). With no group differences, the resting metabolic rate (RMR) was elevated with 15–22% 2 h after exercise.

Conclusion

Overweight women achieved an energy expenditure of approximately 300 kcal (4.7 kcal per min) during a single session of BodyPump, which was similar with the women performing a single session of heavy load resistance exercise.

Long-Term Effects in the EXERDIET-HTA Study: Supervised Exercise Training vs. Physical Activity Advice

Purpose: To determine whether improvements in cardiorespiratory fitness (CRF), blood pressure (BP) and body composition previously seen after a 16-week exercise intervention (POST) with hypocaloric diet are maintained following six months (6M) of unsupervised exercise time. Methods: Overweight/obese, physically inactive participants with primary hypertension (HTN) (n = 190) were randomly assigned into an attention control group (physical activity recommendations) or one of three supervised exercise groups. After POST, all participants received diet and physical activity advice for the following 6M but no supervision. All anthropometric and physiological measurements were taken pre and post the 16-week supervised intervention period, as well as after 6M of no supervision. Results: After 6M: 1) body mass (BM) (Δ = 2.5%) and waist circumference (Δ = 1.8%) were higher (P < .005) than POST, but lower (P < .005) than pre-intervention (BM, Δ = -5.1%; waist circumference, Δ = -4.7%), with high-volume and high-intensity interval training group revealing a higher BM reduction (Δ = -6.4 kg) compared to control group (Δ = -3.5 kg); 2) BP variables were higher (P < .001) compared to POST with no change from pre-intervention; and 3) CRF was higher compared to pre-intervention (Δ = 17.1%, P < .001) but lower than POST (Δ = -5.7%, P < .001). Conclusions: When an overweight/obese population with HTN attains significant improvements in cardiometabolic health POST intervention with diet restriction, there is a significant reduction following 6M when exercise and diet supervision is removed, and only recommendations were applied. These results suggest the need for a regular, systematic and supervised diet and exercise programs to avoid subsequent declines in cardiometabolic health.

Mechanistic and methodological perspectives on the impact of intense interval training on post-exercise metabolism

The post-exercise recovery period is associated with an elevated metabolism known as excess post-exercise oxygen consumption (EPOC). The relationship between exercise duration and EPOC magnitude is thought to be linear whereas the relationship between EPOC magnitude and exercise intensity is thought to be exponential. Accordingly, near-maximal and supramaximal protocols such as high-intensity interval training (HIIT) and sprint interval training (SIT) protocols have been hypothesized to produce greater EPOC magnitudes than submaximal moderate-intensity continuous training (MICT). This review updates previous reviews by focusing on the impact of HIIT and SIT on EPOC. Research to date suggests small differences in EPOC post-HIIT compared to MICT in the immediate (<1 hour) recovery period, but greater EPOC values post-HIIT when examined over 24 hours. Conversely, differences in EPOC post-SIT are more pronounced, as SIT tends to produce a larger EPOC vs MICT at all time points. We discuss potential mechanisms that may drive the EPOC response to interval training (eg, glycogen resynthesis, mitochondrial uncoupling, and protein turnover among others) and also consider the role of EPOC as one of the potential contributors to fat loss following HIIT/SIT interventions. Lastly, we highlight a number of methodological shortcomings related to the measurement of EPOC following HIIT and SIT.

Energy Compensation Following a Supervised Exercise Intervention in Women Living With Overweight/Obesity Is Accompanied by an Early and Sustained Decrease in Non-structured Physical Activity

Background/Objectives

Body composition (BC) does not always vary as a function of exercise induced energy expenditure (exercise EE – resting EE). Energy balance variables were measured to understand energy compensation (EC) in response to an exercise intervention performed at low (LOW) or moderate (MOD) intensity.

Subjects/Methods

Twenty-one women with overweight/obesity (33 ± 5 kg/m²; 29 ± 10 yrs; 31 ± 4 ml O₂/kg/min) were randomized to a 3-month LOW or MOD (40 or 60% of VȮ_2reserve, respectively) matched to expend 1500 kcal/week (compliance = 97 ± 5%). Body energy stores (DXA), energy intake (EI) (food menu and food diaries), resting EE (indirect calorimetry), total EE (doubly-labeled water), time spent in different activities (accelerometers), appetite (visual analog scale), eating behavior traits and food reward (liking and wanting) were assessed at baseline, after weeks 1 and 2 and at the end of the 3-month exercise intervention.

Results

EC based on BC changes (fat mass and fat-free mass) was 49 ± 79% and 161 ± 88% in LOW and MOD groups, respectively (p = 0.010). EI did not change significantly during the intervention. However, eating behavior traits and food reward had changed by the end of the 3-month supervised exercise. Non-structured physical activity (NSPA) decreased across the intervention (p < 0.002), independent of the intensity of the exercise training.

Conclusion

Women with overweight/obesity training at LOW presented lower EC for a given energy cost of exercise. Our results strongly suggest that NSPA plays a major role in mediating the effects of exercise on energy balance and ultimately on changes in BC.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier ISRCTN31641049.

Training-induced changes in daily energy expenditure: Methodological evaluation using wrist-worn accelerometer, heart rate monitor, and doubly labeled water technique

INTRODUCTION

Wrist-mounted motion sensors can quantify the volume and intensity of physical activities, but little is known about their long-term validity. Our aim was to validate a wrist motion sensor in estimating daily energy expenditure, including any change induced by long-term participation in endurance and strength training. Supplemental heart rate monitoring during weekly exercise was also investigated.

METHODS

A 13-day doubly labeled water (DLW) measurement of total energy expenditure (TEE) was performed twice in healthy male subjects: during two last weeks of a 12-week Control period (n = 15) and during two last weeks of a 12-week combined strength and aerobic Training period (n = 13). Resting energy expenditure was estimated using two equations: one with body weight and age, and another one with fat-free mass. TEE and activity induced energy expenditure (AEE) were determined from motion sensor alone, and from motions sensor combined with heart rate monitor, the latter being worn during exercise only.

RESULTS

When body weight and age were used in the calculation of resting energy expenditure, the motion sensor data alone explained 78% and 62% of the variation in TEE assessed by DLW at the end of Control and Training periods, respectively, with a bias of +1.75 (p <.001) and +1.19 MJ/day (p = .002). When exercise heart rate data was added to the model, the combined wearable device approach explained 85% and 70% of the variation in TEE assessed by DLW with a bias of +1.89 and +1.75 MJ/day (p <.001 for both). While significant increases in TEE and AEE were detected by all methods as a result of participation in regular training, motion sensor approach underestimated the change measured by DLW: +1.13±0.66 by DLW, +0.59±0.69 (p = .004) by motion sensor, and +0.98±0.70 MJ/day by combination of motion sensor and heart rate. Use of fat-free mass in the estimation of resting energy expenditure removed the biases between the wearable device estimations and the golden standard reference method of TEE and demonstrated a training-induced increase in resting energy expenditure by +0.18±0.13 MJ/day (p <.001).

CONCLUSIONS

Wrist motion sensor combined with a heart rate monitor during exercise sessions, showed high agreement with the golden standard measurement of daily TEE and its change induced by participation in a long-term training protocol. The positive findings concerning the validity, especially the ability to follow-up the change associated with a lifestyle modification, can be considered significant because they partially determine the feasibility of wearable devices as quantifiers of health-related behavior.

Effect of interval exercise versus continuous exercise on excess post-exercise oxygen consumption during energy-homogenized exercise on a cycle ergometer

PURPOSE

The purpose of this study was to confirm that the difference in excess post-exercise oxygen consumption (EPOC) during exercise of the spending the same calories between the continuous and interval exercise.

METHODS

Thirty-four healthy college students who did not regularly exercise volunteered to participate in our study. Continuous exercise was performed on an ergometer for 30 min at 60% of maximal oxygen consumption (VO2 max). Interval exercise was performed on a cycle ergometer at 80% VO2 max for 2 min initially, followed by 40% VO2 max for 1 min, and 80% VO2 max for 3 min. This was repeated six times for a total of 26 min.

RESULTS

The major findings were as follows: (1) energy consumption during exercise was not significantly different between continuous exercise and interval exercise groups; (2) EPOC was higher in interval exercise than in continuous exercise for all dependent variables (i.e., total oxygen consumption, total calories, summation of heart rate); and (3) there were no significant differences in the lipid profile between continuous and interval groups.

CONCLUSION

Our study confirmed that after equalizing energy expenditure for continuous and interval exercise on a cycle ergometer in subjects in their twenties, interval exercise results in higher EPOC than continuous exercise. These data suggest that interval exercise may be more effective than continuous exercise in reducing body fat, for a given amount of energy expenditure.

High-intensity interval exercise induces greater acute changes in sleep, appetite-related hormones, and free-living energy intake than does moderate-intensity continuous exercise

The aim of this study was to compare the effect of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on sleep characteristics, appetite-related hormones, and eating behaviour. Eleven overweight, inactive men completed 2 consecutive nights of sleep assessments to determine baseline (BASE) sleep stages and arousals recorded by polysomnography (PSG). On separate afternoons (1400–1600 h), participants completed a 30-min exercise bout: either (i) MICE (60% peak oxygen consumption) or (ii) HIIE (60 s of work at 100% peak oxygen consumption: 240 s of rest at 50% peak oxygen consumption), in a randomised order. Measures included appetite-related hormones (acylated ghrelin, leptin, and peptide tyrosine tyrosine) and glucose before exercise, 30 min after exercise, and the next morning after exercise; PSG sleep stages; and actigraphy (sleep quantity and quality); in addition, self-reported sleep and food diaries were recorded until 48 h after exercise. There were no between-trial differences for time in bed (p = 0.19) or total sleep time (p = 0.99). After HIIE, stage N3 sleep was greater (21% ± 7%) compared with BASE (18% ± 7%; p = 0.02). In addition, the number of arousals during rapid eye movement sleep were lower after HIIE (7 ± 5) compared with BASE (11 ± 7; p = 0.05). Wake after sleep onset was lower following MICE (41 min) compared with BASE (56 min; p = 0.02). Acylated ghrelin was lower and glucose was higher at 30 min after HIIE when compared with MICE (p ≤ 0.05). There were no significant differences between conditions in terms of total energy intake (p ≥ 0.05). HIIE appears to be more beneficial than MICE for improving sleep quality and inducing favourable transient changes in appetite-related hormones in overweight, inactive men. However, energy intake was not altered regardless of exercise intensity.

Association of Increased Serum S100B Levels With High School Football Subconcussive Head Impacts

Astrocyte-enriched marker, S100B, shows promise for gauging the severity of acute brain trauma, and understanding subconcussive effects will advance its utility in tracking real-time acute brain damage. The aim of the study was to investigate whether serum S100B elevations were associated with frequency and magnitude of subconcussive head impacts in adolescents. This prospective cohort study of 17 high-school football players consisted of the following 12 time points: pre-season baseline, 5 in-season pre-post games, and post-season. A sensor-installed mouthguard recorded the number of head impacts, peak linear (PLA) and peak rotational (PRA) head accelerations from every practice and game. During the 5 games, players wore chest-strap heart-rate monitors to estimate players' excess post-exercise oxygen consumption (EPOC), accounting for physical exertion effects. At each time point, blood samples were obtained and assessed for S100B and creatine kinase levels to account for astrocyte damage/activation and muscle damage, respectively. Using k-means clustering on the impact data, players were categorized into high- or low-impact group. Two players withdrew during the first month of the study. A total of 156 blood samples from 15 players were assessed for S100B and creatine kinase levels and included in the analysis. A median value of 596 head impacts from 15 players were recorded during all practices and games in a season. S100B levels were significantly elevated in all post-game measures compared with the respective pre-game values (median-increase, 0.022 μg/L; interquartile-range, 0.011–0.043 μg/L, p < 0.05 for all games). Greater acute S100B increases were significantly associated with greater impact frequency, sum of PLA and PRA, with negligible contributions from physical exertion and muscle damage effects. The high-impact group exhibited greater increases in serum S100B levels at post-games than the low-impact group (high vs. low, 0.043 ± 0.035 μg/L vs. 0.019 ± 0.017 μg/L, p = 0.002). The degree of acute S100B increases was correlated with subconcussive head impact exposure, suggesting that acute astrocyte damage may be induced in an impact-dependent manner. Acute changes in serum S100B levels may become a useful tool in monitoring real-time brain damage in sports.

Comparison of Long and Short High-Intensity Interval Exercise Bouts on Running Performance, Physiological and Perceptual Responses

This study compared the effects of long (4×4 min) and short intervals (4×8×20 s) of high-intensity interval exercise bouts (HIIT) on running performance, physiological and perceptual responses, and excess postexercise oxygen consumption (EPOC). Twelve healthy college students (8 men, 4 women; mean age=22±2 years) performed long (90-95% of peak heart rate) and short intervals (maximal intensity) of high-intensity training (running on a non-motorized treadmill) with the same total duration on separate days. The total volume of consumed oxygen during recovery was the same in both cases ( P =0.21), whereas the short intervals of high-intensity training were performed at a faster mean running velocity (3.5±0.18 vs. 2.95±0.07 m/s) and at a lower RPE _breath compared with the long intervals of high-intensity training. The blood lactate concentration also tended to be lower during the short intervals of high-intensity training, indicating that short-interval training was perceived to be easier than long-interval training, even though the cardiovascular and metabolic responses are similar. Furthermore, EPOC lasted significantly longer (83.4±3.2 vs. 61.3±27.9 min, P =0.016) and tended to be higher (8.02±4.22=vs. 5.70±3.75 L O ₂ , P =0.053) after short intervals than after long intervals of training.

Excess Postexercise Oxygen Consumption and Fat Utilization Following Submaximal Continuous and Supramaximal Interval Running

PURPOSE

Few studies have directly compared excess postexercise oxygen consumption (EPOC) and fat utilization following different exercise intensities, and the effect of continuous exercise exceeding 75% of maximal oxygen uptake (VO₂max) on these parameters remains unexplored. The current study examined EPOC and fat utilization following acute moderate- and vigorous-intensity continuous training (MICT and VICT) and sprint interval training (SIT).

METHODS

Eight active young men performed 4 experimental sessions: (a) MICT (30 min of running at 65% VO₂max); (b) VICT (30 min of running at 85% VO₂max); (c) SIT (4 30-s "all-out" sprints with 4 min of rest); and (d) no exercise (REST). Excess postexercise oxygen consumption and fat oxidation were estimated from gas measurements (VO₂ and carbon dioxide production [VCO₂]) obtained during a 2-hr postexercise period.

RESULTS

Total EPOC was similar (p = .097; effect size [ES] = 0.3) after VICT (8.6 ± 4.7 L) and SIT (10.0 ± 4.2 L) and greater after both (VICT, p = .025, ES = 0.3, and SIT, p < .001, ES = 0.6) versus MICT (6.0 ± 4.3 L). Fat utilization increased after MICT (0.047 ± 0.018 g· min^-1, p = .018, ES = 1.3), VICT (0.066 ± 0.020 g•min^-1, p = .034, ES = 2.2), and SIT (0.115 ± 0.026 g•min^-1, p < .001, ES = 4.0) versus REST (0.025 ± 0.018 g•min^-1) and was greatest after SIT (p < .001, ES = 3.0 vs. MICT; p = .031, ES = 2.1 vs. VICT).

CONCLUSION

Acute exercise increases EPOC and fat utilization in an intensity-dependent manner.

Prolonged Sitting Interrupted by 6-Min of High-Intensity Exercise: Circulatory, Metabolic, Hormonal, Thermal, Cognitive, and Perceptual Responses

The aim was to examine certain aspects of circulatory, metabolic, hormonal, thermoregulatory, cognitive, and perceptual responses while sitting following a brief session of high-intensity interval exercise. Twelve students (five men; age, 22 ± 2 years) performed two trials involving either simply sitting for 180 min (SIT) or sitting for this same period with a 6-min session of high-intensity exercise after 60 min (SIT+HIIT). At T₀ (after 30 min of resting), T₁ (after a 20-min breakfast), T₂ (after sitting for 1 h), T₃ (immediately after the HIIT), T₄, T₅, T₆, and T₇ (30, 60, 90, and 120 min after the HIIT), circulatory, metabolic, hormonal, thermoregulatory, cognitive, and perceptual responses were assessed. The blood lactate concentration (at T₃-T₅), heart rate (at T₃-T₆), oxygen uptake (at T₃-T₇), respiratory exchange ratio, and sensations of heat (T₃-T₅), sweating (T₃, T₄) and odor (T₃), as well as perception of vigor (T₃-T₆), were higher and the respiratory exchange ratio (T₄-T₇) and mean body and skin temperatures (T₃) lower in the SIT+HIIT than the SIT trial. Levels of blood glucose and salivary cortisol, cerebral oxygenation, and feelings of anxiety/depression, fatigue or hostility, as well as the variables of cognitive function assessed by the Stroop test did not differ between SIT and SIT+HIIT. In conclusion, interruption of prolonged sitting with a 6-min session of HIIT induced more pronounced circulatory and metabolic responses and improved certain aspects of perception, without affecting selected hormonal, thermoregulatory or cognitive functions.

Effectiveness of a 16-Week High-Intensity Cardioresistance Training Program in Adults

Greenlee, TA, Greene, DR, Ward, NJ, Reeser, GE, Allen, CM, Baumgartner, NW, Cohen, NJ, Kramer, AF, Hillman, CH, and Barbey, AK. Effectiveness of a 16-week high-intensity cardioresistance training program in adults. J Strength Cond Res 31(9): 2528–2541, 2017—The purpose of this study was to determine the efficacy of a novel, 16-week high-intensity cardioresistance training (HICRT) program on measures of aerobic fitness, agility, aerobic power, muscular endurance, lower-body explosive power, and self-reported activity level. The intervention group (N = 129; 63 f, 24.65 ± 5.55 years) had a baseline V̇o₂max of 39.83 ± 9.13. These individuals participated in 26, 70-minute exercise sessions, and 4 fitness testing sessions. Participants were matched with a nonexercise control group, paired by sex, age, and baseline V̇o₂max. Matched controls (N = 129, 63 f, 24.26 ± 5.59 years) had a baseline V̇o₂max of 39.86 ± 8.59 and completed preintervention and postintervention V̇o₂max testing only. The results demonstrate that participants in the fitness intervention group significantly increased their V̇o₂max (2.72 ± 0.31, M_diff ± SE; p < 0.001) and reported being more physically active (0.42 ± 0.11, M_diff ± SE; p < 0.001) after the intervention. The matched control group showed no significant pre–post intervention changes. Participants in the fitness intervention showed a significant improvement in 3 of 5 components of the fitness field tests. Specifically, significant improvements were observed for the 1-minute rower (5.32 ± 0.505, M_diff ± SE; p < 0.001), 1-minute push-up (8.168 ± 0.709, M_diff ± SE; p < 0.001), and 1.5-mile run tests (1.79 ± 0.169, M_diff ± SE; p < 0.001). No significant improvements were observed for the shuttle run (p = 0.173) or standing long jump (p = 0.137). These findings demonstrate the efficacy of a novel, HICRT intervention across multiple dimensions of fitness for young- and middle-aged adults. High-intensity cardioresistance training affords flexibility for tailoring to meet desired health and fitness outcomes and makes perceivably daunting high-intensity functional training and multimodal sports training more accessible to general, traditionally nonathletic, populations.

Effects of walking with hand-held weights on energy expenditure and excess postexercise oxygen consumption

Walking is not only important to assist in performing daily tasks, but also to gain cardiovascular benefits. Further research on walking is needed to examine the physiological responses to improve health and reduce the risks of cardiovascular disease. The purpose of this study was to compare the energy expenditure (EE) during and after walking exercise with versus without hand-held weights (HHW). Nineteen sedentary women (mean±standard deviation; age, 21±2.7 years, height, 163.1±6.3 cm; body mass, 66.6± 15.1 kg; body fat %, 30.6%± 7.43%; body mass index, 25.5± 5.7 kg/m²) volunteered walking with versus without 1.36 kg of HHW in two randomized sessions. The study consisted of 30 min of exercise followed b silent sitting for 30 min. The range of motion was set at elbow flexion at 90° while arms were alternated 30.48 cm forward and backward. 1% incline was set for the treadmill grade and speed was controlled to a moderate level of 40%–59% of heart rate reserve. During the 30-min exercise no significant differences were found between the conditions (P> 0.05). The physiological responses were significantly greater directly after exercise compared with baseline as determined from pairwise comparisons collapsed across conditions (P≤ 0.05). Walking with HHW was not substantial enough to raise EE beyond normal walking and led to an increased effort level. Additionally, the moderate intensity of walking was not enough to sustain EE at a surpassing level directly after the exercise.

Skin temperature response to unilateral training measured with infrared thermography

This study aimed to identify the skin temperature (Tsk) behavior to understand the acute cross-effect after unilateral training of lower-limbs. Seventeen healthy young men (weight, 75.2±5.5 kg; height, 1.8±0.1 m; age, 22.5±1.6 years) were divided into two groups: high-trained (n=8) and low-trained (n=9). All participants performed: (a) one-repetition maximum (1RM) testing protocol on the leg press, (b) a unilateral training protocol (4×10 repetitions at 70% of 1RM for leg press and 4×10 repetitions at 50% of 1RM for knee extension). Pre- and posttraining thermal images were recorded. The main results showed that independent of the limb (exercised vs. nonexercised), differences between low- and high-trained were observed for all regions of interest (ROI) except for the anterior knee: posttraining, 30-min and 60-min posttraining in nonexercised limb. The increase of contralateral Tsk was more than 50% on the ROIs corresponding to the exercises muscles 30-min post-training in low-trained but was not so high in high-trained (P<0.05). Low-trained subjects incremented more the Tsk than high-trained in both legs after exercise. In conclusion, we observed an acute contralateral Tsk effect to unilateral training on the Tsk of the nonexercised limb, reliant on the training level of the subject.

Excess postexercise oxygen consumption and fat oxidation in recreationally trained men following exercise of equal energy expenditure: comparisons of spinning and constant endurance exercise

BACKGROUND

Spinning exercise is one of the most popular types of exercise in fitness industry. Its effects on the post exercise metabolism compared to the isocaloric cyclic endurance exercise are not fully understood. The aim of the present study was to compare the effects of isocaloric (299.1±10.8 kcal) spinning vs. endurance exercise on fat and carbohydrate utilization, glucose, lactate, glycerol and NEFA blood concentration during exercise and recovery.

METHODS

Six recreationally active males (age: 23.5±0.71) were tested in two conditions: 1) 30-min spinning; 2) isocaloric continuous exercise. Each trial was followed by a 3-h recovery. Rates of carbohydrate and fat oxidation, the blood glucose, lactate, glycerol and NEFA concentration were assessed at rest, during exercise and recovery.

RESULTS

Spinning induced significantly higher fat and lower carbohydrate oxidation rate during a recovery period in comparison to isocaloric endurance exercise trial. Spinning induced almost six-fold higher increase in lipid to carbohydrate oxidation rate ratio at the beginning of second hour of postexercise period in comparison to constant intensity trial and reached similar values at 3 hours after exercise. Blood lactate was higher (P<0.01) at the end of exercise in spinning than continuous exercise (8.57±0.9 vs. 0.72±0.1 mmol·L-1), but became similar at the 60 min of recovery.

CONCLUSIONS

These data indicate that spinning induces higher metabolic responses during recovery period, and most effectively shifts the pattern of substrate use toward lipids vs. isocaloric endurance exercise.