High-Intensity Warm-Up Increases Anaerobic Energy Contribution during 100-m Sprint

Effects of sex differences on energy providing capacities during short duration high-intensity exercise: focusing on changes in exercise duration

BACKGROUND

This study aimed to examine the effects of sex differences on each energy supply (phosphagen, glycolytic, and oxidative systems) when athletes performing short-duration high-intensity exercises for different durations.

METHODS

Eight male and seven female college students specializing in tracks and fields participated in this experiment. They performed full-strength pedaling for the experimental exercise. The participants were asked to pedal at a load of 6.5% of their body weight (kp) for three conditions: 10, 30, and 50 s. The phosphagen system was calculated by considering the fast component of the excess post-exercise oxygen consumption after all tests. The glycolytic system was expressed as the delta value of the difference between the peak and baseline blood lactate concentrations measured during the test. The oxidative system was estimated by subtracting the baseline oxygen uptake from the area of sprint oxygen uptake.

RESULTS

At 10 s, a significant correlation was found between the relative mean power and the phosphagen and glycolytic systems in males. At 30 s, a significant correlation was found between relative mean power and phosphagen and oxidative systems in males, and between glycolytic and oxidative systems in females. At 50 s, a significant correlation was found between relative mean power and oxidative systems in males.

CONCLUSIONS

The results of this study indicate that the energy delivery systems supporting high performance in short-duration high-intensity exercise differ between males and females, a finding that is valuable for developing training plans.

Third-Man-Passing Small-Sided Games Induce Higher Anaerobic Energy Contributions Than Regular-Passing Small-Sided Games in Football Players

PURPOSE

This study compared the physiological profiles and energy-system contributions of trained football players engaged in regular-passing and third-man-passing small-sided games (SSGs) that included 4 versus 4 and a goalkeeper.

METHODS

Ten male trained football players participated in this crossover study. All participants were randomly assigned to either regular-passing SSG or third-man-passing SSG (4 vs 4 with a goalkeeper, 35-m × 17-m pitch size, and 6-min match duration). During these SSGs, physiological parameters including peak and mean heart rate, oxygen uptake (V˙O2peak and V˙O2mean), metabolic equivalents in V˙O2peak and V˙O2mean, and blood lactate concentrations (peak La- and delta La- [Δ La-]), were measured. Energy contributions (oxidative [WOxi], glycolytic [WGly], and phosphagen [WPCr] systems) and Global Positioning System (GPS) variables (total distance, total acceleration counts, mean speed, and maximum speed) were also analyzed.

RESULTS

No significant differences in physiological parameters and GPS variables were found between regular- and third-man-passing SSGs. WOxi in kilojoules and percentages was significantly higher during both SSGs than WPCr and WGly (P < .0001, respectively). WPCr and WPCr + WGly values during third-man-passing SSGs were significantly higher than those during regular-passing SSGs (P < .05). Additionally, low to moderate positive correlations were observed between WOxi, WGly in kilojoules, V˙O2peak, V˙O2mean, peak La-, Δ La-, total acceleration counts, and mean speed (r = .39-.64).

CONCLUSIONS

Third-man-passing SSGs may be useful for increasing anaerobic capacity. More third-man-passing SSG sessions in preparation for football games may support high metabolic power and repeated powerful anaerobic performances in trained football players.

The contribution of energy systems during 15-second sprint exercise in athletes of different sports specializations

Background

Long-term adaptations and ongoing training seem to modify the energy system contribution in highly trained individuals. We aimed to compare the energy metabolism profile during sprint exercise in athletes of different specialties.

Methods

Endurance (n = 17, 20.3 ± 6.0 yrs), speed-power (n = 14, 20.3 ± 2.5 yrs), and mixed (n = 19, 23.4 ± 4.8 yrs) athletes performed adapted 15-second all-out test before and after a general preparation training period. The contribution of phosphagen, glycolytic, and aerobic systems was calculated using the three-component PCr-LA-O2 method.

Results

Between-group differences were observed in the contribution of energy systems in the first and second examinations. The proportions were 47:41:12 in endurance, 35:57:8 in team sports, and 45:48:7 in speed-power athletes. Endurance athletes differed in the phosphagen (p < 0.001) and glycolytic systems (p = 0.006) from team sports and in the aerobic system from speed-power athletes (p = 0.003). No substantial shifts were observed after the general preparatory phase, except a decrease in aerobic energy contribution in team sports athletes (p = 0.048).

Conclusion

Sports specialization and metabolic profile influence energy system contribution during sprint exercise. Highly trained athletes show a stable energy profile during the general preparation phase, indicative of long-term adaptation, rather than immediate training effects.

Sex Differences in the Energy System Contribution during Sprint Exercise in Speed-Power and Endurance Athletes

Background/Objectives: A high level of specific metabolic capacity is essential for maximal sprinting in both male and female athletes. Various factors dictate sex differences in maximal power production and energy utilization. This study aims to compare the contribution of energy systems between male and female athletes with similar sport-specific physiological adaptations during a 15-s sprint exercise. Methods: The endurance group consisted of 17 males (23 ± 7 y) and 17 females (20 ± 2 y). The speed-power group included 14 males (21.1 ± 2.6 y) and 14 females (20 ± 3 y). The contribution of phosphagen, glycolytic, and aerobic systems was determined using the three-component PCr-LA-O2 method. Results: Significant differences were observed in the energy expenditure for all systems and total energy expenditure between males and females in both groups (p = 0.001-0.013). The energy expenditure in kJ for individual systems (phosphagen-glycolytic-aerobic) was 35:25:7 vs. 20:16:5 in endurance males vs. female athletes, respectively. In the speed-power group, male athletes expended 33:37:6 kJ and female athletes expended 21:25:4 kJ, respectively. The percentage proportions did not differ between males and females in any system. The contribution of the phosphagen-glycolytic-aerobic systems was 52:37:11 vs. 48:39:13 in endurance male and female athletes, respectively. For speed-power males vs. female athletes, the proportions were 42:50:8 vs. 41:50:9, respectively. Conclusions: Despite the differences in body composition, mechanical output, and absolute energy expenditure, the energy system contribution appears to have a similar metabolic effect between male and female athletes engaged in sprint exercises with similar sport-related adaptations. The magnitude and profile of sex differences are related to sports discipline.

V ˙ Lamax: determining the optimal test duration for maximal lactate formation rate during all-out sprint cycle ergometry

PURPOSE

This study aimed to ascertain the optimal test duration to elicit the highest maximal lactate formation rate ( V ˙ Lamax), whilst exploring the underpinning energetics, and identifying the optimal blood lactate sampling period.

METHODS

Fifteen trained to well-trained males (age 27 ± 6 years; peak power: 1134 ± 174 W) participated in a randomised cross-over design completing three all-out sprint cycling tests of differing test durations (10, 15, and 30 s). Peak and mean power output (W and W.kg-1), oxygen uptake, and blood lactate concentrations were measured. V ˙ Lamax and energetic contributions (phosphagen, glycolytic, and oxidative) were determined using these parameters.

RESULTS

The shortest test duration of 10 s elicited a significantly (p = 0.003; p < 0.001) higher V ˙ Lamax (0.86 ± 0.17 mmol.L-1.s-1; 95% CI 0.802-0.974) compared with both 15 s (0.68 ± 0.18 mmol.L-1.s-1; 95% CI 0.596-0.794) and 30 s (0.45 ± 0.07 mmol.L-1.s-1; 95% CI 0.410-0.487). Differences in V ˙ Lamax were associated with large effect sizes (d = 1.07, d = 3.15). We observed 81% of the PCr and 53% of the glycolytic work completed over the 30 s sprint duration was attained after 10 s. BLamaxpost were achieved at 5 ± 2 min (ttest 10 s), 6 ± 2 min (ttest 15 s), and 7 ± 2 min (ttest 30 s), respectively.

CONCLUSION

Our findings demonstrated a 10 s test duration elicited the highest V ˙ Lamax. Furthermore, the 10 s test duration mitigated the influence of the oxidative metabolism during all-out cycling. The optimal sample time to determine peak blood lactate concentration following 10 s was 5 ± 2 min.

Increased resting lactate levels and reduced carbohydrate intake cause νLa.max underestimation by reducing net lactate accumulation-A pilot study in young adults

Modulation of testing conditions such as resting lactate (Larest) levels or carbohydrate intake may affect the calculation of the maximal glycolytic rate (νLa.max). To evaluate the impact of elevated Larest as well as reduced and increased carbohydrate availability on νLa.max in running sprints (RST), twenty-one participants completed five 15-s RST tests on a running track under five different conditions: (I). baseline: Larest ≤1.5 mmol·L-1; (II). Lactate+: Larest ≥2.5 mmol·L-1; (III). CHO-: carbohydrate intake: ≤ 1 g·kg-1 BW d-1 for 3 days; (IV). CHO+: carbohydrate intake: ≥ 9 g·kg-1 BW d-1 for one day; and (V). acuteCHO: 500 mL glucose containing beverage consumed before RST. νLa.max was significantly reduced in lactate+ and CHO- conditions compared to the baseline RST, due to a reduction in the arithmetic mean delta (∆) between Lapeak and Larest lactate concentration (Lapeak, mmol · L-1). AcuteCHO led to an increase in Larest compared to baseline, CHO- and CHO+ with a high interindividual variability but did not significantly reduce νLa.max. Therefore, avoiding low carbohydrate nutrition before νLa.max testing, along with carefully adjusting Larest to below ≤1.5 mmol·L-1, is crucial to prevent the unintentional underestimation of νLa.max.

A modified formula using energy system contributions to calculate pure maximal rate of lactate accumulation during a maximal sprint cycling test

Purpose: This study aimed at comparing previous calculating formulas of maximal lactate accumulation rate ( ν La.max) and a modified formula of pure ν La.max (P ν La.max) during a 15-s all-out sprint cycling test (ASCT) to analyze their relationships. Methods: Thirty male national-level track cyclists participated in this study (n = 30) and performed a 15-s ASCT. The anaerobic power output (Wpeak and Wmean), oxygen uptake, and blood lactate concentrations (La-) were measured. These parameters were used for different calculations of ν La.max and three energy contributions (phosphagen, W PCr; glycolytic, W Gly; and oxidative, W Oxi). The P ν La.max calculation considered delta La-, time until Wpeak (tPCr-peak), and the time contributed by the oxidative system (tOxi). Other ν La.max levels without tOxi were calculated using decreasing time by 3.5% from Wpeak (tPCr -3.5%) and tPCr-peak. Results: The absolute and relative W PCr were higher than W Gly and W Oxi (p < 0.0001, respectively), and the absolute and relative W Gly were significantly higher than W Oxi (p < 0.0001, respectively); ν La.max (tPCr -3.5%) was significantly higher than P ν La.max and ν La.max (tPCr-peak), while ν La.max (tPCr-peak) was lower than P ν La.max (p < 0.0001, respectively). P ν La.max and ν La.max (tPCr-peak) were highly correlated (r = 0.99; R 2 = 0.98). This correlation was higher than the relationship between P ν La.max and ν La.max (tPCr -3.5%) (r = 0.87; R 2 = 0.77). ν La.max (tPCr-peak), P ν La.max, and ν La.max (tPCr -3.5%) were found to correlate with absolute Wmean and W Gly. Conclusion: P ν La.max as a modified calculation of ν La.max provides more detailed insights into the inter-individual differences in energy and glycolytic metabolism than ν La.max (tPCr-peak) and ν La.max (tPCr -3.5%). Because W Oxi and W PCr can differ remarkably between athletes, implementing their values in P ν La.max can establish more optimized individual profiling for elite track cyclists.

Effects of individualized low-intensity mat Pilates on aerobic capacity and recovery ability in adults

PURPOSE

Although Pilates is one of the most widely performed physical activities in Korea, no physiological evidence is available regarding its energy recovery ability. Therefore, the purpose of this study was to investigate the effects of individualized low-intensity mat Pilates on aerobic capacity and recovery ability in adults.

METHODS

Ten physically active women participated in this study. Pre- and post-lactate threshold (LT) tests were performed to compare jogging/running speeds (S; km·h-1) and heart rates (HR; beats·min-1) at 1.5, 2.0, 3.0, 4.0 mmol·L-1 lactate concentrations (La-). Subjects performed 1 h of low-intensity mat Pilates twice a week for four weeks. During these sessions, exercise intensity was determined based on the heart rate corresponding to individualized low-inten- sity recovery zone 1, which was estimated using a mathematical model of log-log LT1 (from pre-test; &lt; 2 mmol·L-1). All physiological variables were measured before and after exercise intervention.

RESULTS

Significant differences were found in body mass increase and body mass index increase between the pre- and post-tests (p = 0.016 and p = 0.014, respectively, effect size (ES) = 0.13; ES = -0.11). Levels of La- between 1.0 and 1.4 m·s-1 in the post-LT test tended to decrease, although such decrease was not significantly different. Moderate to high positive correlations between differences (Δ) of S and ΔHR at 1.5, 3.0, and 4.0 mmol·L-1La- were observed.

CONCLUSION

Positive correlations between ΔS and ΔHR at certain La- levels indicate that low-intensity mat Pilates based on heart rate corresponding to individualized recovery zone 1 might be recommended for physically active adults.

Physiological Profiling and Energy System Contributions During Simulated Epée Matches in Elite Fencers

PURPOSE

The aim of this study was to investigate physiological responses and energetic contributions during simulated epée matches in elite fencers.

METHODS

Ten elite male fencers participated in simulated epée (direct elimination) matches. Simulated epée matches included 3 bouts of 3 minutes each with 1-minute rests between bouts. During these sessions, physiological variables such as mean and peak heart rate, peak and mean oxygen uptake (VO2peak and VO2mean), metabolic equivalents of task in VO2peak and VO2mean, and blood lactate concentrations (peak lactate concentration and delta blood lactate concentration) were measured. Furthermore, energetic contributions (oxidative [WOxi], glycolytic, and phosphagen) and time-motion variables were estimated.

RESULTS

Values of peak heart rate, mean heart rate, and WOxi (in percentages) were significantly higher in the second and third bouts compared with the first. VO2peak and metabolic equivalents of task in VO2peak were significantly higher in the first bout compared with the third bout. Values of delta blood lactate concentration and glycolytic contribution (in kilojoules and percentages) were significantly lower in the second and third bouts compared with the first. VO2mean and metabolic equivalents of task in VO2mean were significantly higher in the second bout compared with the third bout. Furthermore, WOxi (in kilojoules and percentage) was significantly higher in all bouts compared with phosphagen and glycolytic contributions. Low positive and negative correlations were seen between WOxi, VO2mean, sum of attacks and defense times, and the sum of time without attacks and defenses.

CONCLUSIONS

Direct-elimination epée matches consist of high-intensity intermittent exercise, and the oxidative contribution is 80% to 90%. Improving aerobic conditioning may support high-intensity intermittent actions during entire epée matches in elite fencers.

Recent Progress in Applicability of Exercise Immunology and Inflammation Research to Sports Nutrition

This article focuses on how nutrition may help prevent and/or assist with recovery from the harmful effects of strenuous acute exercise and physical training (decreased immunity, organ injury, inflammation, oxidative stress, and fatigue), with a focus on nutritional supplements. First, the effects of ketogenic diets on metabolism and inflammation are considered. Second, the effects of various supplements on immune function are discussed, including antioxidant defense modulators (vitamin C, sulforaphane, taheebo), and inflammation reducers (colostrum and hyperimmunized milk). Third, how 3-hydroxy-3-methyl butyrate monohydrate (HMB) may offset muscle damage is reviewed. Fourth and finally, the relationship between exercise, nutrition and COVID-19 infection is briefly mentioned. While additional verification of the safety and efficacy of these supplements is still necessary, current evidence suggests that these supplements have potential applications for health promotion and disease prevention among athletes and more diverse populations.

Metabolic Energy Contributions During High-Intensity Hatha Yoga and Physiological Comparisons Between Active and Passive (Savasana) Recovery

Purpose: The objective of this study was to investigate metabolic energy contributions during high-intensity hatha yoga (HIHY) and to compare changes in physiological variables between active and passive recovery methods.

Methods: The study involved 20 women yoga instructors (n = 20) who performed 10 min of HIHY (vigorous sun salutation). Upon completion, they were randomly assigned to either active (walking; n = 10) or passive (savasana; n = 10) recovery groups for a period of 10 min. During HIHY, physiological variables such as heart rate (HR_peak and HR_mean), oxygen uptake (VO_2peak and VO_2mean), and blood lactate concentrations (peak La⁻) were measured. Energetic contributions (phosphagen; W_PCR, glycolytic; W_Gly, and oxidative; W_Oxi) in kJ and % were estimated using VO₂ and La⁻ data. Furthermore, the metabolic equivalents (METs) of VO_2peak and VO_2mean were calculated. To compare different recovery modes, HR_post, ΔHR, VO_2post, ΔVO₂, recovery La⁻, and recovery ΔLa⁻ were analyzed.

Results: The results revealed that HR_peak, VO_2peak, and peak La⁻ during HIHY showed no differences between the two groups (p > 0.05). Values of HR_peak, HR_mean, METs of VO_2peak and VO_2mean, and La⁻ during HIHY were 95.6% of HR_max, 88.7% of HR_max, 10.54 ± 1.18, 8.67 ±.98 METs, and 8.31 ± 2.18 mmol·L⁻¹, respectively. Furthermore, W_Oxi was significantly higher compared with W_PCR, W_Gly, and anaerobic contribution (W_PCR + W_Gly), in kJ and % (p < 0.0001). VO_2post and recovery ΔLa⁻ were significantly higher in the active recovery group (p < 0.0001, p = 0.0369, respectively). Values of ΔVO₂ and recovery La⁻ were significantly lower in the active group compared with the passive group (p = 0.0115, p = 0.0291, respectively).

Conclusions: The study concluded that high-intensity hatha yoga which was performed for 10 min is a suitable option for relatively healthy people in the modern workplace who may have hatha yoga experience but do not have time to perform a prolonged exercise. Following active recovery, they can participate in further HIHY sessions during short breaks. Furthermore, a faster return to work can be supported by physiological recovery.