The Effects of Short-Term Detraining and Subsequent Retraining on Body Composition and Muscle Performance in Males Consuming a Whey Protein or Carbohydrate Supplement

An acute bout of resistance exercise (RE) can up-regulate processes that stimulate muscle protein synthesis (MPS). Additionally, nutritional strategies involving carbohydrate (CHO) and whey protein (WP) supplementation can augment MPS. However, resistance training (RT) induced muscle anabolism during the early phases of training can attenuate over time. The use of a short-term cessation of training (detraining; DT) can potentially restore the attenuated muscular anabolic adaptive responses. Therefore, the purpose of this study was to explore the effects of a successive cycle of detraining and retraining (ReT) in humans on body composition and muscle performance. Resistance-trained males (age 20.95 ± 1.23 y; n=20) were recruited and randomized into one of two groups (WP or CHO; 25 grams) in a double-blind fashion. Both groups followed a standardized 4 days per week resistance-training program for 4 weeks, carried out 2 weeks of DT and continued the resistance-training program for another 4 weeks of ReT. Participants were instructed to consume their respective supplement only on workout days during RT, but every day during DT. Research visits were conducted at baseline, 4 weeks (post-RT), 6 weeks (post-2-week-DT), and after 10 weeks (post-ReT). Each visit consisted of body composition assessments and muscular strength and endurance testing using the bench press and angled leg press exercises. Four-day diet records, workout logs, and supplement compliance forms were utilized. Factorial 2x4 (group by time) ANOVAs with repeated measures were conducted using SPSS (version 20.0) with a probability level of ≤ .05. There were no significant group by time interactions for lean or fat mass changes throughout the study (p \u3e .05). However, both groups were able to retain lean mass following 2 weeks of DT. The WP group appeared to have an elevation in lean mass (+1.58kg on average) by the end of ReT in comparison to baseline, even though it was not statistically significant (p \u3e .05). Leg press strength (LPS) increased throughout the study (p=.003), and neither group showed a decrease in LPS following DT. There were no group-by-time interactions or group differences between WP and CHO for bench press strength (BPS), bench press endurance (BPE), leg press endurance (LPE), or any dietary variables (p \u3e .05). Interestingly, the WP group presented a non-significant overall increase in lean mass compared to the CHO group by the end of 10 weeks. LPS and BPS were also elevated and retained respectfully following DT. In summary, a short-term 2 week cycle of DT in resistance trained males maintained both muscle mass and muscular strength, which potentially reinforces the importance of recovery

The effectiveness of fish oil supplementation in attenuating eccentric exercise-induced muscle damage in females during mid-follicular and mid-luteal menstrual phases

Due to the supposed cyto-protective effects of estrogen, females are thought to be less predisposed to EIMD than males, but may be more prone to muscle damage during the low estrogen point in their 28-day cycle (follicular phase) compared to their high estrogen point (luteal phase). Fish oil supplementation has been suggested to be important for cyto-protection due to its anti-oxidant potential for significantly decreasing markers of muscle damage. In a double-blind fashion 22 physically-active females were randomly assigned to ingest either 6 grams of fish oil (n = 11) or a placebo (n = 11) daily for 21 days. Participants underwent an eccentric exercise bout of the knee extensors on two occasions, during the mid-luteal phase (day 21) and mid-follicular phase (day 6) of the 28-day menstrual cycle. Prior to, at 6, and 24 hours post-exercise for each session, participants underwent assessment of DOMS, muscle strength, and had venous blood samples and muscle biopsies obtained. Criterion variables included serum markers of muscle damage, inflammation, and oxidative stress (SOD, myoglobin, TNF-α), skeletal muscle markers of NF-κB signaling, DOMS, and muscle strength. Data was analyzed utilizing a 2 x 2 x 3 repeated measures MANOVA. Further analysis of the main effects for Test was performed by a separate one-way ANOVA. Significant between-group differences were then determined involving the Tukey LSD Post Hoc Test. The alpha level for statistical significance was set at p ≤ .05. DOMS was significantly greater at the 6HRPOST and 24HRPOST time points compared to PRE (p ≤ .05). SOD concentrations were significantly higher at the MF phase compared to the ML phase (p ≤ .05). TNF-α concentrations were significantly higher in the experimental group compared to the placebo group (p < .05), and at the MF phase compared to the ML phase (p < .05). There were no significant differences observed for muscle strength, myoglobin, NF-KB p50 or p65. The results of this study demonstrate that estrogen, but not fish oil supplementation, may exert a cyto-protective effect on the sarcolemma

Effect of Bang® Pre-Workout Master Blaster® combined with four weeks of resistance training on lean body mass, maximal strength, mircoRNA expression, and serum IGF-1 in men: a randomized, double-blind, placebo-controlled trial

Background The aim of the current study was to determine if 4 weeks of consumption of Bang® Pre-Workout Master Blaster® (BMB; Vital Pharmaceuticals Inc., Weston, FL) combined with resistance training resulted in greater increases in muscle mass and maximal strength compared with resistance training combined with placebo (PLA). Additionally, we aimed to determine if BMB ingestion combined with resistance training preferentially altered resting skeletal muscle expression of microRNAs (miRs) or resting serum insulin-like growth factor (IGF-1). Methods Sixteen recreationally-active men completed the study. The study employed a block-randomized, double-blind, placebo-controlled, parallel design. Participants completed two testing sessions separated by 4 weeks of resistance exercise combined with daily supplementation of BMB or PLA. At each testing session, hemodynamics, body composition, and muscle and blood samples were obtained followed by strength assessments of the lower- and upper-body via measurement of squat and bench press one-repetition maximum (1-RM), respectively. A separate general linear model was utilized for analysis of each variable to determine the effect of each supplement (between-factor) over time (within-factor) using an a priori probability level of ≤0.05. Results No significant effects were observed for dietary intake, hemodynamics, fat mass, body fat percentage, or serum IGF-1. A greater increase in total body mass (3.19 kg, 95% CI, 1.98 kg, 4.40 kg vs. 0.44 kg, 95% CI, − 0.50 kg, 1.39 kg) and lean body mass (3.15 kg, 95% CI, 1.80 kg, 4.49 kg vs. 0.89 kg, 95% CI, − 0.14 kg, 1.93 kg) was observed for the BMB group compared with PLA (p <  0.01). A significant increase over time was observed for miR-23a (p = 0.02) and miR-23b (p = 0.05) expression. A greater increase in squat 1-RM was observed for the BMB group (23.86 kg, 95% CI, 16.75 kg, 30.97 kg) compared with the PLA group (14.20 kg, 95% CI, 7.04 kg, 21.37 kg, p = 0.04). Conclusions BMB supplementation combined with resistance exercise training for 4 weeks resulted in superior adaptations in maximal strength and LBM compared with resistance training with a placebo. No adverse resting hemodynamic or clinical blood safety markers were observed as a result of BMB supplementation. The superior outcomes associated with BMB supplementation could not be explained by resting serum IGF-1 or the skeletal muscle miRs measured, although resting miR-23a and miR-23b expression both increased as a result of resistance training

Effects of Five Weeks of Resistance Training and Relatively-Dosed Creatine Monohydrate Supplementation on Body Composition and Muscle Strength, and Whole-Body Creatine Metabolism in Resistance-Trained Males

Background: Creatine (Cr) supplementation has been established as an ergogenic aid in most individuals during anaerobic exercise. However, discrepancies exist in the data when using absolute dosing.  Objective: The effects of five weeks of resistance training with relatively-dosed Cr followed by four weeks of resistance training after ceasing supplementation were determined. Methods: Resistance-trained men, 19 (CR = 9, PL = 10), ingested Cr or placebo for five weeks with resistance training. Participants ingested 0.3 g/kg lean body mass/day for one week, 0.075 g/kg lean body mass/day for four weeks, with a four-week wash out. Five muscle samples, six blood samples, and nine urine samples were collected. Separate two-way ANOVAs for each criterion variable were used employing an alpha level of ≤ 0.05. Results: A group x time interaction for increased total body mass for CR Day 1 and 64 (p = 0.03) and total lean mass for CR Day 1 and 64 (p = 0.01). Group x time interactions occurred for Cr supplementation increasing serum Cr at Day 4, 8, and 22 (p = 0.03), urinary Cr at Day 4 (p = 0.01), and total muscle Cr at Day 8 (p < 0.001), 22 (p = 0.003), and 36 (p < 0.001). No significant differences occurred for serum (p = 0.14) or urine (p = 0.15) creatinine. Conclusion: Elevated levels of urinary Cr demonstrate dosing could be reduced.Keywords: Urine, creatinine, resistance training, muscle strength, seru

Eight Weeks of Phosphatidic Acid Supplementation in Conjunction with Resistance Training Does Not Differentially Affect Body Composition and Muscle Strength in Resistance-Trained Men

This study attempted to determine the effects of eight weeks of resistance training (RT) combined with phosphatidic acid (PA) supplementation at a dose of either 250 mg or 375 mg on body composition and muscle size and strength. Twenty-eight resistance-trained men were randomly assigned to ingest 375 mg [PA375 (n = 9)] or 250 mg [PA250 (n = 9)] of PA or 375 mg of placebo [PLC (n = 10)] daily for eight weeks with RT. Supplements were ingested 60 minutes prior to RT and in the morning on non-RT days. Participants’ body composition, muscle size, and lower-body muscle strength were determined before and after training/supplementation. Separate group x time ANOVAs for each criterion variable were used employing an alpha level of ≤ 0.05. Magnitude- based inferences were utilized to determine the likely or unlikely impact of PA on each criterion variable. A significant main effect for time was observed for improvements in total body mass (p = 0.003), lean mass (p = 0.008), rectus femoris cross-sectional area [RF CSA (p = 0.011)], and lower-body strength (p 0.05). Collectively, magnitude-based inferences determined both doses of PA to have a likely impact of increasing body mass (74.2%), lean mass (71.3%), RF CSA (92.2%), and very likely impact on increasing lower-body strength (98.1% beneficial). When combined with RT, it appears that PA has a more than likely impact on improving lower-body strength, whereas a likely impact exists for increasing muscle size and lean mass

Skeletal Muscle Estrogen Receptor Activation in Response to Eccentric Exercise Up-Regulates Myogenic-Related Gene Expression Independent of Differing Serum Estradiol Levels Occurring during the Human Menstrual Cycle

This study sought to determine if the differences in serum estradiol we have previously observed to occur during the mid-follicular (MF) and mid-luteal (ML) phases of the female menstrual cycle could be attributed to estrogen-induced receptor activation and subsequent effects on myogenic-related genes which may otherwise impact muscle regeneration in response to eccentric exercise. Twenty-two physically-active females (20.9 ± 1.4 years, 63.5 ± 9.0 kg, 1.65 ± 0.08 m) underwent an eccentric exercise bout of the knee extensors during the MF and ML phases of their 28-day menstrual cycle. Prior to (PRE), at 6 (6HRPOST), and 24 (24HRPOST) hours post-exercise for each session, participants had muscle biopsies obtained. Skeletal muscle estradiol and estrogen receptor-α (ER-α) content and ER-DNA binding were determined with ELISA. Real-time PCR was used to assess ER-α, Myo-D, and cyclin D1 mRNA expression. Data were analyzed utilizing a 2 x 3 repeated measures univariate analyses of variance (ANOVA) for each criterion variable (p ≤ .05). Skeletal muscle estradiol levels were not significantly impacted by either menstrual phase (p > 0.05); however, both ER-α mRNA and protein were significantly increased during MF (p < 0.05). ER-DNA binding and Myo-D mRNA expression increased significantly in both menstrual phases in response to exercise but were not different from one another; however, cyclin D1 mRNA expression was significantly greater during MF. This study demonstrates that skeletal muscle ER-α activation in response to eccentric exercise up-regulates myogenic-related gene expression independent of serum estradiol levels occurring during the human menstrual cycle

Acute (-)-Epicatechin Consumption: Effects on Local Vasodilation Following Resistance Exercise and High-Intensity Exercise Performance

(-)-Epicatechin is a polyphenol previously shown to enhance vascular health. The purposes of the current studies were to determine the effect of acute (-)-epicatechin supplementation on local vasodilation in conjunction with resistance exercise (study 1) and on high-intensity exercise performance (study 2). For study 1, 11 men participated in two resistance exercise sessions, where they performed three sets of barbell curls while consuming 200 mg of 98% pure (-)-epicatechin or placebo. Measurements of total serum nitrate/nitrite and brachial artery diameter were acquired at baseline (pre-supplement), 90 min after supplement consumption (post-supplement), immediately post-exercise (post-exercise), and 30 min post-exercise (30 min post-exercise). For serum nitric oxide metabolites, no significant interaction between supplement and time nor significant main effect of time was observed (p = 0.38 and p = 0.20; respectively). For brachial artery diameter, no significant interaction between supplement and time was observed (p = 0.24). A significant main effect of time was observed for brachial artery diameter (p &lt; 0.01) with post-exercise brachial artery diameter significantly greater diameter than all other time points (all p &lt; 0.01). For study 2, six women and five men completed the 15.5 CrossFit&reg; Open Workout three times. A familiarization session was performed first where the workout was performed without the consumption of a supplement. In a randomized, balanced fashion, 100 mg of 98% pure (-)-epicatechin or cellulose (placebo) was consumed two times per day for two days before testing sessions two and three. On the day of testing sessions two and three, 60 to 90 min before completing the workout, 200 mg of the assigned supplement was ingested with water. No significant difference was observed for time to complete the workout between testing sessions (p = 0.49). In conclusion, under the conditions of the current studies, acute (-)-epicatechin supplementation did not augment vasodilation in combination with resistance exercise, nor did it increase exercise performance in humans