Effects of concurrent training sequence on VO2max and lower limb strength performance: A systematic review and meta-analysis

Concurrent training effects on H reflex, V wave and contractile properties of the plantar flexors: insights into different resistance training types

PURPOSE

This study explored neuromuscular adaptations following 11 weeks of concurrent training (CT) compared to resistance-only (R) and endurance-only (E) in trained men.

METHODS

Thirty participants were randomized into three groups (E, R, CT), training three times per week. Neuromuscular assessments involved plantar-flexion maximal voluntary isometric contraction (MVIC), rate of torque development (RTD), evoked potentials (H reflex and V wave) and contractile properties at baseline, mid-training (week 5), and post-training. Resistance training for R and CT groups involved two phases: weeks 1-5 (maximal strength development) and weeks 6-11 (explosive/reactive strength and muscle power development). Endurance training for the E and CT groups involved 30-min of running on the heavy-intensity domain.

RESULTS

MVIC increased similarly in the R and CT groups. The R group significantly improved peak and sequential RTD, soleus electromyographic (EMG) activity, V wave and contractile properties. Conversely, the CT group exhibited an interference effect during the first phase with no improvements in RTD or neuromuscular parameters. During the second phase, the CT group exhibited significant enhancements in sequential RTD, soleus EMG activity, H- and V-wave amplitude. The improvements in the E group were limited to H-reflex excitability.

CONCLUSION

These findings suggest that the magnitude of CT interference is modulated by the focus of resistance training (maximal vs explosive strength) being performed. However, it is relevant to note that contractile impairments seem to persist, likely due to endurance training in the heavy-intensity domain.

Sequencing Effects of Concurrent Resistance and Short Sprint Interval Training on Physical Fitness, and Aerobic and Anaerobic Performance of Karate Athletes

This study aimed to evaluate the effects of an 8-week concurrent training (CT) program that combined short sprint interval training (sSIT) and resistance training (RT) in alternating sequences (i.e., sSIT + RT or RT + sSIT) on the physical fitness, aerobic capacity, and anaerobic performance of male karate athletes, in comparison to each training intervention conducted independently. Forty national-level young male athletes volunteered to participate in this study and were divided into sSIT, RT, sSIT + RT, RT + sSIT, and active control (CG) groups, each group consisted of eight athletes and performed 3 days of weekly training intervention including 4 sets of 5 repetitions of 5 seconds of all-out running for sSIT program and also back squats, leg presses, seated knee flexions, and calf raises for 3 sets of 6-12 repetition maximum for the RT intervention. After the intervention, the sSIT, RT, sSIT + RT and RT + sSIT groups demonstrated improvements in the countermovement vertical jump (CMVJ) (effect size [ES] = 0.64, 0.88, 1.58, 1.55), 20-m sprint (ES = -0.82, -0.62, -1.10, -1.16), 4 × 9-m shuttle run (ES = -0.62, -0.35, -1.15, -0.89), strength (ES = 0.19, 0.44, 0.34, 0.43), peak (ES = 1.27, 0.73, 1.80, 1.53), and mean power output (ES = 0.87, 0.54, 1.37, 1.11), as well as in comparison to the CG (p < 0.05), respectively. Additionally, improvements in aerobic performance were observed in the sSIT, sSIT + RT, and RT + sSIT groups (ES = 0.75, 0.92, 0.62) after the training intervention, and in comparison to CG (p < 0.05), while the RT group did not show significant changes post-training. By comparing the CT groups, no sequencing effects were observed in the adaptations of variables between the sSIT + RT vs. RT + sSIT groups. In conclusion, this study's findings demonstrate that sSIT, RT, and CT with different orders have a positive impact on inducing adaptations in physical fitness, aerobic and anaerobic performance. Additionally, combining sSIT and RT resulted in further adaptations in karate athletes without any differences between CT groups.

Effects of the hospital-community-family trinity cardiac rehabilitation on patients with acute myocardial infarction after percutaneous coronary intervention: A randomized trial

Objectives

This study aimed to develop a hospital-community-family trinity cardiac rehabilitation (CR) intervention program and assess its' effects on patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI).

Methods

Between April 2022 and April 2023, patients who had experienced AMI after PCI were enrolled. These patients were randomly assigned to an intervention group (IG) or a control group (CG) in equal numbers. The CG received standard CR, while the IG participated in the advanced trinity CR program in addition to the standard CR. Key parameters measured included the anaerobic threshold (AT), maximum oxygen uptake (V̇O2max), maximum exercise load (MEL), metabolic equivalent (MET), left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), and quality of life (measured by the SF-36). These were assessed pre-intervention and at 3, 6, 9, and 12 months post-intervention. SPSS.26 was employed for data analysis, with statistical methods such as repeated measures analysis of variance (ANOVA), Chi-square tests, and independent sample t-tests.

Results

A total of 110 patients completed the intervention, 55 in each group. There was no significant difference in the scores of all indicators between the two groups before intervention (P > 0.05). However, at 3, 6, 9 and 12 months after intervention, the scores of AT, VO2max, MEL, MET, LVEDV, LVESV, LVEF, and quality of life in the intervention group were higher than those in the control group, there was statistical significance at four-time points, group, time, and interaction effect (P < 0.05).

Conclusions

The hospital-community-family trinity CR intervention program developted in this study significantly improved exercise endurance, cardiac function, and quality of life in patients with AMI after PCI.

Impact of Different Low-Volume Concurrent Training Regimens on Cardiometabolic Health, Inflammation, and Fitness in Obese Metabolic Syndrome Patients

BACKGROUND/OBJECTIVES

Evidence supports the benefits of concurrent training (CT), which combines endurance and resistance exercises, for enhancing health and physical fitness. Recently, low-volume, time-efficient exercise approaches such as low-volume high-intensity interval training (LOW-HIIT), whole-body electromyostimulation (WB-EMS), and single-set resistance training (1-RT) have gained popularity for their feasibility and efficacy in improving various health outcomes. This study investigated the effects of low-volume CT, focusing on (1) whether exercise order affects cardiometabolic health, inflammation, and fitness adaptations and (2) which combination, LOW-HIIT plus WB-EMS or LOW-HIIT plus 1-RT, yields better results.

METHODS

Ninety-three obese metabolic syndrome (MetS) patients undergoing caloric restriction were randomly assigned to four groups performing the different low-volume CT protocols over 12 weeks. Outcomes included cardiometabolic, inflammatory, and fitness parameters.

RESULTS

In both combinations, no significant differences were found regarding exercise order. However, the pooled LOW-HIIT and 1-RT group achieved superior improvements in blood pressure, blood lipids, inflammation markers (CRP, hsCRP), the MetS severity score, and overall fitness compared to the LOW-HIIT and WB-EMS combination. Compared to previous studies using these modalities individually, LOW-HIIT plus 1-RT appeared to further reduce inflammation, whereas LOW-HIIT combined with WB-EMS was less effective for cardiometabolic health, potentially due to interference effects between modalities.

CONCLUSIONS

While LOW-HIIT plus WB-EMS appears to be a viable option for individuals unable to perform traditional resistance training, the findings suggest prioritizing LOW-HIIT plus 1-RT to maximize health outcomes. These findings highlight the importance of tailored exercise prescriptions and the need for further research into optimizing CT protocols for diverse populations.

Synergistic Effects of Concurrent Aerobic and Strength Training on Fitness in Children and Adolescents: A Multivariate and Network Meta-Analysis

The decline in fitness levels among children and adolescents underscores the urgent need for effective exercise interventions. Aerobic endurance training (ET) and resistance training (RT) are vital for physical development in this demographic. This study employs multivariate and network meta-analysis (NMA) to assess the impact of concurrent training (CT), which integrates both ET and RT, on youth physical fitness. The objective is to identify the distinct advantages of CT over either ET or RT alone, emphasizing demographic and training-specific variables. A systematic literature review of publications from 1980 onward was conducted through ISI Web of Science, PubMed/MEDLINE, and SPORTDiscus databases, adhering to the PICOS criteria for study selection. Data were analyzed using univariate, multivariate, and network meta-analyses in Stata 17.0, focusing on cardiorespiratory fitness and muscular strength. The methodological quality and risk of bias were evaluated using the PEDro scale and Egger's test, along with sensitivity analyses and meta-regression to explore heterogeneity and publication bias. This analysis included 36 studies with 2658 participants (mean age: 14.32 ± 2.29 years) from an initial 11 074 publications, indicating low bias risk (PEDro scores ≥ 6). Univariate meta-analysis showed no significant differences in maximal oxygen uptake (VO2max) between CT and ET (standardized mean difference [SMD] = 0.01; 95% confidence interval [CI]: -0.23 to 0.25; p = 0.93). In contrast, CT significantly improved countermovement jump (CMJ) compared to RT alone (SMD = 0.19; 95% CI: 0.01-0.36; p = 0.04). Multivariate analysis confirmed notable enhancements in endurance and explosiveness for CT compared to ET or RT. NMA indicated significant improvements in lower limb strength, CMJ, and VO2max across interventions compared to controls, with the consecutive resistance training followed by ET (CRE) group yielding the most significant CMJ improvement (SMD = 0.27; 95% CI: 0.07-0.47). Isolated RT showed the highest lower limb strength improvement (SUCRA score 80.1%), while CRE excelled in CMJ advancements (SUCRA score 93.4%), and the CRED group (alternating ET and RT) led in VO2max improvements (SUCRA score 81.6%). Furthermore, high-intensity interval training (HIIT) significantly enhanced VO2max compared to team sports. This meta-analysis emphasizes the effectiveness of CT in improving muscle power and VO2max in children and adolescents, surpassing isolated ET or RT, and advocates for integrating ET and RT to optimize physical performance. Future research should explore the mechanisms underlying these enhancements. Trial Registration: PROSPERO registration number CRD42022368452.

Short- and long-term effects of concurrent aerobic and resistance training on circulating irisin levels in overweight or obese individuals: a systematic review and meta-analysis of randomized controlled trials

Background

Concurrent training (CT) is emerging as a practical and effective approach to enhance body composition, cardiovascular function, and muscle mass, thereby elevating overall individual health. This study aims to systematically investigate the effects of short- and long-term concurrent aerobic and resistance training on circulating irisin levels in overweight or obese individuals.

Methodology

The electronic databases, including China National Knowledge Infrastructure, PubMed, Embase, Wan Fang Database, and Web of Science, were systematically searched for articles on "concurrent training" and "irisin" published from their inception to 30 November 2023. The pooled effect size was determined using standardized mean difference (SMD) and corresponding 95% confidence intervals (CIs). The study protocol received registration with the International Prospective Register of Systematic Reviews (CRD42023494163).

Results

All nine studies, encompassing a total of 264 participants, were randomized controlled trials and met the eligibility criteria. Results indicate that short- and long-term concurrent training moderately increased circulating irisin levels compared to the control group (SMD = 0.56, 95% CI [0.33-0.80], p = 0.00; I 2 = 36.6%, heterogeneity p = 0.106). Subgroup analyses revealed that both equal to or less than 10 weeks (SMD = 0.78, 95% CI [0.18-1.37], p = 0.01; I 2 = 62.3%, heterogeneity p = 0.03) and more than 10 weeks (SMD = 0.45, 95% CI [0.14-0.76], p = 0.00; I 2 = 0%, heterogeneity p = 0.54) of concurrent training significantly increased circulating irisin levels in overweight or obese individuals. There were no significant between-group differences (I 2 = 0%, p = 0.34). Additionally, concurrent training significantly increased irisin levels in overweight or obese participants (SMD = 1.06, 95% CI [0.34-1.78], p = 0.00; I 2 = 50.6%, heterogeneity p = 0.13) and in type 2 diabetes patients (SMD = 0.70, 95% CI [0.30-1.10], p = 0.00; I 2 = 0%, heterogeneity p = 0.99). However, no significant effect was observed in patients with metabolic syndrome (SMD = 0.21, 95% CI [-0.25-0.68], p = 0.37; I 2 = 38.7%, heterogeneity p = 0.18). There were significant between-group differences (I 2 = 53.9%, p = 0.11). Lastly, concurrent training significantly increased circulating irisin levels in overweight or obese individuals aged 45-60 years (SMD = 0.56, 95% CI [0.25-0.86], p = 0.00; I 2 = 6.5%, heterogeneity p = 0.38), and a significant increase in irisin levels was observed 12 h post-intervention (SMD = 0.70, 95% CI [0.35-1.05], p = 0.00; I 2 = 0%, heterogeneity p = 0.74). However, none of the above categorical variables showed significant between-group differences.

Conclusions

Short- and long-term concurrent training can effectively improve circulating irisin levels in overweight or obese individuals. However, the effects of short- and long-term concurrent training should consider the participants' health status, age, and the timing of post-exercise measurements to maximize health benefits.

Effect of Strength and Endurance Training Sequence on Endurance Performance

This review investigates the effect of two different concurrent training sequences on endurance performance. The sequences investigated are Endurance-Resistance (ER) and Resistance-Endurance (RE). A literature search is conducted of the SPORTDiscus and Medline databases. The included studies are randomized control trials, which compare the effect of ER and RE on at least one endurance performance variable. A PEDro scale is used to assess the methodological quality of the articles in this review. Of a total of 152 articles identified during the initial screening, 15 studies meet the inclusion criteria. These studies include 426 participants (298 males and 128 females), with 212 of the participants training with ER and 214 with RE. The results are presented as the percentage change of the mean from pre- to post-test. All the studies show an improvement in endurance from pre to post for both interventions, except for the RE group in one study. This review finds small and non-conclusive sequence effects between ER and RE, suggesting that the sequence of concurrent training is not of great importance in relation to endurance performance.

Effects of high-intensity interval training on strength, speed, and endurance performance among racket sports players: A systematic review

This study aims to present a critical review of the existing literature on the effects of High-Intensity Interval Training (HIIT) on strength, speed, and endurance performance among racket sports athletes. This study conducted a systematic literature review by PRISMA guidelines. Various well-known academic and scientific databases were used for research collection, including PubMed, EBSCOhost, Scopus, Web of Science, and Google Scholar. Out of 27 relevant studies, 10 were selected for inclusion in this systematic review, all meeting the required inclusion criteria. The quality of each study was assessed using the PEDro scale, with scores ranging from 3 to 5 for the selected studies. HIIT was found to improve racket players' VO2 max (maximum oxygen uptake), running and repetitive sprint performance, jumping performance, and hitting speed during play. Current findings indicate that HIIT can significantly benefit athletic performance. Long-term HIIT allows athletes to enhance their power while improving crucial variables related to both aerobic and anaerobic endurance. This anaerobic endurance and explosive power type is particularly vital for racket sports players. For example, athletes in table tennis and badminton must exert maximum effort during high-intensity middle and back-court play. Racket athletes also need to maintain a stable state while preserving ball speed and positioning, and must quickly recover to prepare for the next rally. This training mechanism can assist athletes in honing their skills and achieving more efficient hitting quality. Therefore, this paper recommends that racket sports athletes incorporate HIIT into their regular training routines. The suggested frequency is three times per week, with each training session lasting 30-40 minutes, and a total duration of six to eight weeks. Trial registration. Systematic Review Registration: [https://inplasy.com/], identififier[INPLASY20230080].