Twelve Weeks Rest–Pause and Traditional Resistance Training: Effects on Myokines and Performance Adaptations among Recreationally Trained Men

A rest–pause (RP) technique involves performing one or more repetitions at high resistance to failure, followed by a short rest before performing one or more repetitions. These techniques can affect neuromuscular conditions and fatigue by changing the rest time between repetitions. This study compared the effect of 12 weeks of RP and traditional resistance training (TRT) on myokines (myostatin (MSTN), follistatin (FLST) and insulin-like growth factor-1 (IGF-1)) and functional adaptations. The study recruited 29 men between the ages of 20 and 30 who had performed resistance training for at least 6 to 12 months. Participants were randomly divided into three groups: RP, TRT, and control; resistance training was performed 3 days per week for 12 weeks. The training methods of the two groups were largely similar. The results showed that RP increased IGF-1 and FLST/MSTN more than the TRT group (% change = 19.04, % change = 37.71), and only the RP and TRT groups had significant changes in the FLST/MSTN ratio compared to the control group (p < 0.001 and p = 0.02, respectively). In addition, FLST levels increased and MSTN decreased in the RP and TRT groups, but the rate of change in FLST was significant in the RP and TRT groups compared to the control group (p = 0.002 and p = 0.001, respectively). Leg press and bench press strength, and arm and thigh muscular cross-sectional area (MCSA) increased more in the RP group than in the others, and the percentage of body fat (PBF) decreased significantly. The change between strength and MCSA was significant (p ≤ 0.05), and the PBF change in RP and TRT compared to the control (ES RP group = 0.43; ES TRT group = 0.55; control group ES = 0.09) was significant (p = 0.005, p = 0.01; respectively). Based on the results, the RP training technique significantly affects strength and muscle hypertrophy more than the TRT method, which can be included in the training system to increase strength and hypertrophy.

Rapid Weight Loss of Up to Five Percent of the Body Mass in Less Than 7 Days Does Not Affect Physical Performance in Official Olympic Combat Athletes With Weight Classes: A Systematic Review With Meta-Analysis

Given the relevance of the effects that weight loss can generate on the physical performance in athletes, this study performed a systematic review with meta-analysis of the published literature on rapid weight loss (RWL) and examined its impact on the physical performance in Official Olympic combat sports athletes. The “Preferred Reporting Items for Systematic Reviews and Meta-Analysis” (PRISMA) guidelines were followed to ensure an ethical and complete reporting of the findings. PubMed, SPORT Discus, and EBSCO were the electronic databases explored for article retrieval and selection. The following string was applied: “RWL” OR “weight loss” OR “weight reduction” AND “judo” OR “wrestling” or “taekwondo” or “boxing” AND “performance.” Based on the quality analysis, conducted according to the “Tool for the assessment of study quality and reporting in exercise training studies” (TESTEX), ten articles achieved a score >6 points. The meta-analysis showed a significant difference in pre- vs. post-weight loss (p = 0.003) and no effects in pre- vs. post-power and strength performance analysis (p > 0.05 for both results). Based on our systematic review and meta-analysis of the literature, RWL up to ≤5% of the body mass in less than 7 days does not influence performance outcomes in Official Olympic combat athletes with weight classes, considering the strength and power measures.

Effects of Soy Milk in Conjunction With Resistance Training on Physical Performance and Skeletal Muscle Regulatory Markers in Older Men

Purpose: We aimed to determine the effects of 12 weeks of soy milk consumption combined with resistance training (RT) on body composition, physical performance, and skeletal muscle regulatory markers in older men. Methods: In this randomized clinical trial study, 60 healthy elderly men (age = 65.63 ± 3.16 years) were randomly assigned to four groups: resistance training (RT; n =  15), soy milk consumption (SMC; n  =  15), resistance training + soy milk (RSM; n = 15), and control (CON; n  =  15) groups. The study was double-blind for the soy milk/placebo. Participants in RT and RSM groups performed resistance training (3 times/week) for 12 weeks. Participants in the SMC and RSM groups consumed 240 mL of soy milk daily. Body composition [body mass (BM), body fat percent (BFP), waist-hip ratio (WHR), and fat mass (FM)], physical performance [upper body strength (UBS), lower body strength (LBS), VO2max, upper anaerobic power, lower anaerobic power, and handgrip strength], and serum markers [follistatin, myostatin, myostatin-follistatin ratio (MFR), and growth and differentiation factor 11 (GDF11)] were evaluated before and after interventions. Results: All 3 interventions significantly (p < 0.05) increased serum follistatin concentrations (RT = 1.7%, SMC = 2.9%, RSM = 7.8%) and decreased serum myostatin (RT = -1.3% SMC = -5.4%, RSM = -0.5%) and GDF11 concentrations (RT = -1.4%, SMC = -1.4%, RSM = -9.0%), and MFR (RT = -2.6%, SMC = -3.2%, RSM = -12%). In addition, we observed significant reduction in all 3 intervention groups in BFP (RT = -3.6%, SMC = -1.4%, RSM = -6.0%), WHR (RT = -2.2%, SMC = -2.1%, RSM = -4.3%), and FM (RT = -9.6%, SMC = -3.8%, RSM = -11.0%). Moreover, results found significant increase only in RT and RSM groups for muscle mass (RT = 3.8% and RSM = 11.8%), UBS (RT = 10.9% and RSM = 21.8%), LBS (RT = 4.3% and RSM = 7.8%), upper anaerobic power (RT = 7.8% and RSM = 10.3%), and lower anaerobic power (RT = 4.6% and RSM = 8.9%). Handgrip strength were significantly increased in all 3 intervention groups (RT = 7.0%, SMC = 6.9%, RSM = 43.0%). VO_2max significantly increased only in RSM (1.7%) after 12 weeks of intervention. Additionally, significant differences were observed between the changes for all variables in the RSM group compared to RT, SMC, and CON groups (p < 0.05). Conclusions: There were synergistic effects of soy milk and RT for skeletal muscle regulatory markers, body composition, and physical performance. Results of the present study support the importance of soy milk in conjunction with RT for older men.

Intensity Dependent Effects of Interval Resistance Training on Myokines and Cardiovascular Risk Factors in Males With Obesity

OBJECTIVE

To determine the effects of different intensities of interval resistance training (IRT) protocols on the levels of select myokines (decorin, follistatin, myostatin, activin A, transforming growth factor beta-1 [TGF-β1]), and cardiometabolic and anthropometric measures in males with obesity.

METHODS

Forty-four obese males (age: 27.5 ± 9.4 yr.; height: 165.4 ± 2.8 cm; weight: 97.9 ± 2.6 kg and BMI: 35.7 ± 4.3 kg/m²) were randomly assigned to one of four groups (n=11 per group): low-intensity interval resistance training (LIIRT), moderate-intensity interval resistance training (MIIRT), high-intensity interval resistance training (HIIRT) or control (C). The LIIRT group performed 10 exercises in 3 sets of 40% (20 repetitions), the MIIRT group performed 10 exercises in three sets of 60% (13 repetitions), and the HIIRT group performed 10 exercises in three sets of 80% (10 repetitions) of one maximum repetition (1RM), which were followed with active rest of 20% of 1RM and 15 repetitions. The resistance training groups exercised ~70 min per session, 3 days per week, for 12 weeks. Measurements were taken at baseline and after 12 weeks of exercise training.

RESULTS

Baseline levels of myokines, cardiovascular risk factors, anthropometry, body composition, and cardio-respiratory fitness were not different between the four groups (p>0.05). The group x time interactions for decorin, activin A, follistatin, myostatin, and TGF-β1, total cholesterol (TC), triglyceride (TG), high-density cholesterol (HDL), low-density cholesterol (LDL), anthropometry, body composition, and cardio-respiratory fitness were statistically significant (p<0.05). There were increases in post-test values for decorin, follistatin, HDL (p<0.05) and decreases in TC, TG, TGF-β1, LDL, and myostatin levels in the LIIRT, MIIRT, and HIIRT groups compared to pretest values (p<0.05). Changes in fat mass, VO_2peak, HDL, TG, glucose, activin A, decorin were not significant in LIIRT compared to the control group, while changes in activin A, follistatin, and TFG-β1 levels were greater in HIIRT and MIIRT groups compared to the LIIRT group (p<0.05).

CONCLUSION

The LIIRT, MIIRT, and HIIRT protocols all produced beneficial changes in decorin, activin A, follistatin, myostatin, and TGF-β1 levels, and cardiometabolic risk factors, with greater effects from the MIIRT and HIIRT protocols compared to LIIRT.

The Effects of TRX Suspension Training Combined with Taurine Supplementation on Body Composition, Glycemic and Lipid Markers in Women with Type 2 Diabetes

Background: We aimed to investigate the effects of an 8-week total-body resistance exercise (TRX) suspension training intervention combined with taurine supplementation on body composition, blood glucose, and lipid markers in T2D females. Methods: Forty T2D middle-aged females (age: 53 ± 5 years, body mass = 84.3 ± 5.1 kg) were randomly assigned to four groups, TRX suspension training + placebo (TP; n = 10), TRX suspension training + taurine supplementation (TT; n = 10), taurine supplementation (T; n = 10), or control (C; n = 10). Body composition (body mass, body mass index (BMI), body fat percentage (BFP)), blood glucose (fasting blood sugar (FBS)), hemoglobin A1c (HbA1c), Insulin, and Insulin resistance (HOMA-IR), and lipid markers (low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), and total cholesterol (TC)) were evaluated prior to and after interventions. Results: All three interventions significantly decreased body mass, BMI, and BFP with no changes between them for body mass and BMI; however, BFP changes in the TT group were significantly greater than all other groups. FBS was significantly reduced in TP and TT. Insulin concentrations’ decrement were significantly greater in all experimental groups compared to C; however, no between group differences were observed between TT, TP, and T. In regards to HOMA-IR, decreases in TT were significantly greater than all other groups TG, HbA1c, and LDL were reduced following all interventions. HDL values significantly increased only in the TT group, while TC significantly decreased in TP and TT groups. Changes in HbA1c, TG, HDL, and TC were significantly greater in the TT compared to all other groups. Conclusions: TRX training improved glycemic and lipid profiles, while taurine supplementation alone failed to show hypoglycemic and hypolipidemic properties. Notably, the synergic effects of TRX training and taurine supplementation were shown in HbA1c, HOMA-IR, TG, TC, HDL, and BFP changes. Our outcomes suggest that TRX training + taurine supplementation may be an effective adjuvant therapy in individuals with T2D.

Spirulina supplementation during gradual weight loss in competitive wrestlers

We aimed to assess the effects of spirulina supplementation during gradual weight loss on serum concentrations of follistatin (FST), myostatin (MST), insulin-like growth factor 1 (IGF-1), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and body composition in competitive wrestlers. Forty competitive wrestlers (age: 22 (sem 2) years) were randomly assigned to one of two groups: gradual weight loss + spirulina (SP; n 20) or gradual weight loss + placebo (PL; n 20). Subjects in both groups lost weight according to a designed diet over 12 d and were required to reduce baseline body mass (BM) by 4%. Subjects in the SP group received two tablets of spirulina, while subjects in the PL received two tablets of placebo before each meal. Concentrations of mentioned serum markers and body composition were measured before and after the interventions. BM (SP = -3·1 kg and PL = -2·9 kg), body fat percentage (BFP) (SP = -2·1 % and PL = -0·6 %), fat mass (FM) (SP = -2·2 kg and PL = -0·9 kg) and skeletal muscle mass (SP = -1·4 kg and PL = -1·5 kg) significantly decreased in both groups (P < 0·05). The changes in BFP and FM were significantly greater in SP compared with the PL group (P < 0·001). Additionally, MST (SP = -0·1 ng/ml), AST (SP = -2·1 u/l) and ALT (SP = -2·7 u/l) concentrations significantly diminished in SP group (P = 0·005), while FST (PL = -0·1 ng/ml) and IGF-1 (PL = -2·6 ng/ml) concentrations significantly decreased in PL group (P < 0·05). Spirulina supplementation during gradual weight loss is beneficial in reducing BFP, FM, MST and liver enzymes while maintaining IGF-1 and FST concentrations in competitive wrestlers.

The effects of gradual vs. rapid weight loss on serum concentrations of myokines and body composition in overweight and obese females

Context: Research has shown the modulations of Follistatin (FST) and Myostatin (MST) following weight loss.Objective: We evaluated the effects of gradual weight loss (GWL) and rapid weight loss (RWL) on serum MST, FST, and body composition in overweight and obese females.Materials and methods: Thirty-six overweight and obese females successfully completed the study interventions: GWL (n = 18) or RWL (n = 18). Serum MST and FST concentrations, as well as anthropometric measurements, were collected at baseline and at the conclusion of each weight loss intervention.Results: MST concentration significantly (p < .05) decreased in the GWL; while FST concentration, body fat percentage and skeletal muscle mass significantly declined in both conditions. The loss in skeletal muscle mass was significantly greater in RWL relative to GWL.Discussion and conclusion: GWL was more effective than RWL in preserving skeletal muscle mass in overweight and obese females. Moreover, GWL leads to declines in MST concentrations.

Effects of branched-chain amino acid supplementation and resistance training in postmenopausal women

BACKGROUND

The age-related loss in muscular function is typically accelerated after menopause. Resistance training (RT) has been shown to increase muscle mass and strength in postmenopausal women. Branched-chain amino acid (BCAA) supplementation acutely increases myofibrillar protein synthesis (MPS) and decreases muscle soreness following RT. However, the combined effects of BCAA supplementation and RT on muscle mass, strength, and regulatory factors on postmenopausal cohorts are currently unknown. The purpose of this study was to explore the combined effects of BCAA supplementation and RT on muscle mass, strength, and regulatory factors in postmenopausal women.

METHODS

Thirty postmenopausal women were randomly assigned to one of three conditions: RT and placebo (PLA; n = 10), RT and BCAA (BCAA; 9 g/day; n = 10), or control (CON; n = 10). Muscle mass, strength, and serum concentrations of muscle regulatory factors (myostatin, follistatin, and insulin-like growth factor-1 [IGF-1]) were assessed before and following 8 weeks of whole-body supervised RT (3×/week, 3-4 sets using 60-75% 1-repetition maximum [1-RM]).

RESULTS

There were significant increases (P < 0.05) in muscle mass and strength in both the PLA and BCAA conditions. Additionally, myostatin significantly (P < 0.05) decreased, while IGF-1 (P < 0.05) increased following PLA and BCAA. However, follistatin significantly increased in the BCAA condition. There were no differences between RT conditions over time. Furthermore, there were no changes in any variable after CON.

CONCLUSIONS

Short-term (8 weeks) RT is an effective intervention for improving muscle mass, strength, and muscle regulatory factors in postmenopausal women. The addition of BCAA supplementation to RT failed to augment these physiological changes.

Comparison of whole egg v. egg white ingestion during 12 weeks of resistance training on skeletal muscle regulatory markers in resistance-trained men

Eggs are considered a high-quality protein source for their complete amino acid profile and digestibility. Therefore, this study aimed to compare the effects of whole egg (WE) v. egg white (EW) ingestion during 12 weeks of resistance training (RT) on the skeletal muscle regulatory markers and body composition in resistance-trained men. Thirty resistance-trained men (mean age 24·6 (sd 2·7) years) were randomly assigned into the WE + RT (WER, n 15) or EW + RT (EWR, n 15) group. The WER group ingested three WE, while the EWR group ingested an isonitrogenous quantity of six EW per d immediately after the RT session. Serum concentrations of regulatory markers and body composition were measured at baseline and after 12 weeks. Significant main effects of time were observed for body weight (WER 1·7, EWR 1·8 kg), skeletal muscle mass (WER 2·9, EWR 2·7 kg), fibroblast growth factor-2 (WER 116·1, EWR 83·2 pg/ml) and follistatin (WER 0·05, EWR 0·04 ng/ml), which significantly increased (P < 0·05), and for fat mass (WER -1·9, EWR -1·1 kg), transforming growth factor-β1 (WER -0·5, EWR -0·1 ng/ml), activin A (WER -6·2, EWR -4·5 pg/ml) and myostatin (WER -0·1, EWR -0·06 ng/ml), which significantly decreased (P < 0·05) in both WER and EWR groups. The consumption of eggs absent of yolk during chronic RT resulted in similar body composition and functional outcomes as WE of equal protein value. EW or WE may be used interchangeably for the dietary support of RT-induced muscular hypertrophy when protein intake is maintained.

Role of serum myostatin in the association between hyperinsulinemia and muscle atrophy in Japanese obese patients

AIMS

The protein myostatin is a member of the transforming growth factor β superfamily. This is mainly expressed in skeletal muscle and negatively regulates skeletal muscle growth. The present study aimed to elucidate the associations among circulating myostatin level, skeletal muscle mass, and metabolic profiles in Japanese obese patients.

METHODS

Japanese obese outpatients (n = 74) were enrolled. We measured clinical parameters, quantified serum myostatin levels, and examined their associations in a cross-sectional manner.

RESULTS

Both total skeletal muscle mass and serum myostatin level were higher in males than in females. Among 74 patients, serum myostatin level was positively correlated with skeletal muscle mass and serum immunoreactive insulin (IRI) level [correlation coefficient (r) = 0.294, P = 0.011; r = 0.262, P = 0.024, respectively]. Furthermore, multivariate linear regression analysis revealed that serum myostatin level was positively correlated with IRI after adjusting for gender and skeletal muscle mass (β-coefficient = 0.230, P = 0.029, R² = 0.236).

CONCLUSIONS

In obese patients, serum myostatin level was elevated in conjunction with an increase in IRI level independent of skeletal muscle mass. This may imply possible novel pathological implications of serum myostatin in muscle mass and metabolism in obese patients with hyperinsulinemia.

Rapid Weight Loss vs. Slow Weight Loss: Which is More Effective on Body Composition and Metabolic Risk Factors?

BACKGROUND

Achieving weight loss (WL) in a short time regardless of its consequences has always been the focus of many obese and overweight people. In this study, anthropometric and metabolic effects of two diets for rapid and slow WL and their consequences were examined.

METHODS

Forty-two obese and overweight individuals were randomly divided to 2 groups; rapid WL (weight loss of at least 5% in 5 weeks) and slow WL (weight loss of at least 5% in 15 weeks). To compare the effects of the rate of WL in 2 groups, the same amount of was achieved with different durations. Anthropometric indices, lipid, and glycemic profiles, and systolic and diastolic blood pressures were evaluated before and after the intervention.

RESULTS

Both protocols of rapid WL and slow WL caused reduction in waist circumference, hip circumference, total body water, body fat mass, lean body mass, and resting metabolic rate (RMR). Further reduction in waist circumference, hip circumference, fat mass, and percentage of body fat was observed in slow WL and decreased total body water, lean body mass, fat free mass, and RMR was observed in rapid WL. Improvement in lipid and glycemic profiles was observed in both groups. Reduction of low-density lipoprotein and fasting blood sugar, improvement of insulin resistance, and sensitivity were more significant in rapid WL in comparison to slow WL.

CONCLUSIONS

Weight Loss regardless of its severity could improve anthropometric indicators, although body composition is more favorable following a slow WL. Both diets improved lipid and glycemic profiles. In this context, rapid WL was more effective. (IRCT2016010424699N2).