Evaluating the Effects of Increased Protein Intake on Muscle Strength, Hypertrophy and Power Adaptations with Concurrent Training: A Narrative Review

A comparison of the effects of two protocols of concurrent resistance and aerobic training on physical fitness in middle school students

Objective

This study aimed to compare the effects of two concurrent training (CT) protocols on the physical fitness of middle school students.

Method

A 12-week quasi-experimental pre-test/post-test study was conducted with 157 middle school students (age = 12.48 ± 0.34, n = 90 females) divided into three groups: CT group A (CT-0h) received combined resistance training (RT) and aerobic training (AT) in each physical education session, CT group B (CT-48h) received RT and AT across two separate physical education classes 48 h apart, and a control group (Con) received no training. Training occurred twice a week. Test indicators included cardiorespiratory fitness (CRF) measured by estimated VO2max and 20 m shuttle run (laps), as well as muscle strength assessed through long jump, vertical jump, and handgrip strength.

Results

The intervention groups exhibited significant increases in estimated VO2max and muscle strength compared to their baseline values (p < 0.05). Both CT-0h and CT-48h groups demonstrated significant improvements in 20 m shuttle run (laps) (mean difference: 8.88 laps, p < 0.01; mean difference: 4.81 laps, p < 0.01, respectively), standing long jump (mean difference: 6.20 cm, p < 0.01; mean difference: 3.68 cm, p < 0.01, respectively), vertical jump (mean difference: 4.95 cm, p < 0.01; mean difference: 4.04 cm, p < 0.01, respectively), and handgrip strength (mean difference: 11.17 kg, p < 0.01; mean difference: 6.99 kg, p < 0.01, respectively). CT-0h group exhibited significantly increased estimated VO2max (mean difference: 1.47 ml/kg/min, p < 0.01) compared to the CT-48h group.

Conclusion

Both CT programs effectively improved adolescents' physical fitness indicators. However, the program that integrated RT and AT within the same physical education class demonstrated superior enhancement in adolescents' CRF.

Resistance-only and concurrent exercise induce similar myofibrillar protein synthesis rates and associated molecular responses in moderately active men before and after training

Aerobic and resistance exercise (RE) induce distinct molecular responses. One hypothesis is that these responses are antagonistic and unfavorable for the anabolic response to RE when concurrent exercise is performed. This thesis may also depend on the participants' training status and concurrent exercise order. We measured free-living myofibrillar protein synthesis (MyoPS) rates and associated molecular responses to resistance-only and concurrent exercise (with different exercise orders), before and after training. Moderately active men completed one of three exercise interventions (matched for age, baseline strength, body composition, and aerobic capacity): resistance-only exercise (RE, n = 8), RE plus high-intensity interval exercise (RE+HIIE, n = 8), or HIIE+RE (n = 9). Participants trained 3 days/week for 10 weeks; concurrent sessions were separated by 3 h. On the first day of Weeks 1 and 10, muscle was sampled immediately before and after, and 3 h after each exercise mode and analyzed for molecular markers of MyoPS and muscle glycogen. Additional muscle, sampled pre- and post-training, was used to determine MyoPS using orally administered deuterium oxide (D2 O). In both weeks, MyoPS rates were comparable between groups. Post-exercise changes in proteins reflective of protein synthesis were also similar between groups, though MuRF1 and MAFbx mRNA exhibited some exercise order-dependent responses. In Week 10, exercise-induced changes in MyoPS and some genes (PGC-1ɑ and MuRF1) were dampened from Week 1. Concurrent exercise (in either order) did not compromise the anabolic response to resistance-only exercise, before or after training. MyoPS rates and some molecular responses to exercise are diminished after training.

Combined Aerobic Training and Mediterranean Diet Is Not Associated with a Lower Prevalence of Sarcopenia in Italian Older Adults

Previous studies found a lower prevalence of sarcopenia in older adults engaged in regular aerobic training (AT) or with greater adherence to a Mediterranean (MED) diet. However, the effect of their combination on sarcopenia indices is unknown. The present study tested the association between AT plus a MED diet and the presence of sarcopenia and its defining elements in a sample of Italian older adults enrolled in the Longevity Check-up 7+ (Lookup 7+) project. Analyses were conducted in participants 65+ years, with a body mass index of at least 18.5 kg/m2, engaged in regular AT, and without missing information for the variables of interest. MED diet adherence was evaluated via a modified version of the MEDI-LITE score and categorized as low, moderate, or high. The presence of sarcopenia was established by handgrip strength and appendicular skeletal muscle mass (ASM) values below sex-specific cut-points recommended by the European Working Group on Sarcopenia in Older People 2. Data from 491 older adults were analyzed for the present study. The mean age was 72.7 ± 5.7 years, and 185 (37.7%) were women. MED diet adherence was low in 59 (12.0%) participants, moderate in 283 (57.6%), and high in 149 (30.3%). Sarcopenia was identified in 26 participants (5.3%), with no differences across MED diet adherence groups. The results of binary logistic regression showed no significant associations between AT plus adherence to a MED diet and dynapenia, low ASM, or sarcopenia. The findings of the present study indicate that the combination of AT with a MED diet is not associated with a lower probability of sarcopenia or its defining elements in Italian older adults enrolled in Lookup 7+. Further research is warranted to establish whether exercise frequency, volume, intensity, and length of engagement in AT impact the association between MED diet and sarcopenia.

RESISTANCE TRAINING EFFECTS ON FATIGUE IN RUNNERS

ABSTRACT Introduction Start-up belongs to the group of fast combination exercises involving power and speed dominated by the short-term exhaustion of the whole body’s power aiming at its displacement at high speed to obtain good results in competition. It is very important to master the technique correctly and to distribute the power reasonably for the acceleration of the start. Objective Explore the effect of aerobic endurance training on speed strength in starts. Methods Taking 16 high-level runners from a university sports team as research objects, 16 athletes were tested according to their test indicators; they were randomly assigned to the experimental group and the control group (8 people each in the experimental group and the control group). Results According to the post-test results of the experiment, the athletic performance of both groups of runners after training was improved, but the improvement in the experimental group was more evident and significant (p<0.05). Conclusion: Start-up aerobic endurance training is very useful for improving endurance and speed in runners. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Effects of Concurrent Strength and HIIT-Based Endurance Training on Physical Fitness in Trained Team Sports Players: A Systematic Review and Meta-Analysis

BACKGROUND

Concurrent strength and HIIT-based endurance training (CT) has merit in time-saving in team sports. However, the effect of CT on physical fitness remained equivocal. This meta-analysis aimed to determine whether CT would produce an interference effect on the development of physical fitness when compared to strength training (ST) or HIIT-based endurance training (HET) alone in trained team sports players.

METHODS

A total of 2478 studies from three databases were screened. 52 full texts were reviewed. Seven studies were finally included and then subgroups were used for quantitative analysis.

RESULTS

Compared to ST alone, CT had a significant effect on the development of maximal lower-body strength in trained team sports players (MD 4.20 kg, 95% CI 0.71-7.68, p = 0.02, I² = 20%), but there was no significant difference between the groups on training adaptation in lower-body power (SMD 0.08, 95% CI -0.23-0.39, p = 0.62, I² = 26%). Furthermore, a sub-group analysis based on the internal organization order of CT revealed that there was no statistically significant subgroup effect between CT and ST alone in all parameters.

CONCLUSIONS

Well-designed CT regimens did not interfere with the development of physical fitness of trained team sports players.

A Novel Plant-Based Protein Has Similar Effects Compared to Whey Protein on Body Composition, Strength, Power, and Aerobic Performance in Professional and Semi-Professional Futsal Players

Introduction

The effects of dietary protein on body composition and physical performance seemingly depend on the essential amino acid profile of the given protein source, although controversy exists about whether animal protein sources may possess additional anabolic properties to plant-based protein sources.

Purpose

To compare the effects of a novel plant-based protein matrix and whey protein supplementation on body composition, strength, power, and endurance performance of trained futsal players.

Methods

Fifty male futsal players were followed during 8 weeks of supplementation, with 40 completing the study either with plant-based protein (N = 20) or whey protein (N = 20). The following measures were assessed: bone mineral content, lean body mass, and fat mass; muscle thickness of the rectus femoris; total body water; blood glucose, hematocrit, C-reactive protein, aspartate aminotransferase, alanine aminotransferase, creatine kinase, creatinine, and estimated glomerular filtration rate; salivary cortisol; maximal strength and 1-RM testing of the back squat and bench press exercises; muscle power and countermovement jump; VO2max and maximal aerobic speed. Subjects were asked to maintain regular dietary habits and record dietary intake every 4 weeks through 3-day food records.

Results

No differences in any variable were observed between groups at baseline or pre- to post-intervention. Moreover, no time*group interaction was observed in any of the studied variables, and a time effect was only observed regarding fat mass reduction.

Conclusions

Supplementing with either a novel plant-based protein matrix or whey protein did not affect any of the variables assessed in high-level futsal players over 8 wks. These results suggest that whey protein does not possess any unique anabolic properties over and above those of plant-based proteins when equated to an essential amino acid profile in the population studied. Furthermore, when consuming a daily protein intake &gt;1.6 g/kg BW.day−1, additional protein supplementation does not affect body composition or performance in trained futsal players, regardless of protein type/source.