BAIBA Does Not Regulate UCP-3 Expression in Human Skeletal Muscle as a Response to Aerobic Exercise.

OBJECTIVE: ß-Aminoisobutyric acid (BAIBA) has shown to modulate uncoupling protein (UCP)-1 expression, which is mainly expressed in white adipose tissue; however, no studies to date have analyzed its potential effect on the main uncoupling protein of skeletal muscle, UCP-3. The main goal of this study was to assess the potential effect of acute aerobic exercise on serum BAIBA and skeletal muscle UCP-3. The secondary goal was to assess the potential involvement of the transcription factors proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and peroxisome proliferator-activated receptor alpha (PPARα), as well as free fatty acids (FFAs) in UCP-3 expression. A tertiary goal of the study was to evaluate the potential effect of consuming a preexercise meal on the outcome of the first 2 objectives. METHODS: In a randomized crossover design, untrained participants performed 2 acute cycling sessions (350 kcal at 70% of their VO2peak) after 2 experimental conditions: (1) consumption of a multi-macronutrient shake and (2) a fasting period of 8 hours. Blood samples were taken at baseline, preexercise, postexercise, 1 hour, and 4 hours postexercise, and muscle biopsies were taken at the last 4 time points. UCP-3 protein concentration and expression, as well as the mRNA expression of PGC-1α and PPARα, were measured in muscle, and BAIBA, glucose, and FFA were measured in serum. RESULTS: Aerobic exercise failed to induce a significant effect on serum BAIBA, PGC-1α, and PPARα regardless on the feeding condition. Despite the lack of effect of exercise on the previous variables, UCP-3 expression and protein concentration significantly increased in the shake condition. CONCLUSION: The expression of human skeletal muscle UCP-3 as a result of exercise might be controlled by factors other than BAIBA.

l-Leucine Increases Skeletal Muscle IGF-1 but Does Not Differentially Increase Akt/mTORC1 Signaling and Serum IGF-1 Compared to Ursolic Acid in Response to Resistance Exercise in Resistance-Trained Men.

OBJECTIVE: Ursolic acid administration following resistance exercise increases mammalian target of rapamycin complex 1 (mTORC1) activity and skeletal muscle IGF-1 concentration in murines in a manner similar to l-leucine yet remains unexamined in humans. This study examined serum and skeletal muscle insulin-like growth factor-1 (IGF-1) and Akt/mTORC1 signaling activity following ingestion of either ursolic acid or l-leucine immediately after resistance exercise. METHODS: Nine resistance-trained men performed 3 lower-body resistance exercise sessions involving 4 sets of 8-10 repetitions at 75%-80% one repetition maximum (1-RM) on the angled leg press and knee extension exercises. Immediately following each session, participants orally ingested 3 g cellulose placebo (PLC), l-leucine (LEU), or ursolic acid (UA). Blood samples were obtained pre-exercise and at 0.5, 2, and 6 hours postexercise. Muscle biopsies were obtained pre-exercise and at 2 and 6 hours postexercise. RESULTS: Plasma leucine increased in LEU at 2 hours postexercise compared to PLC (p = 0.04). Plasma ursolic acid increased in UA at 2 h and 6 hours postexercise compared to PLC and LEU (p < 0.003). No significant differences were observed for serum insulin (p = 0.98) and IGF-1 (p = 0.99) or skeletal muscle IGF-1 receptor (IGF-1R; p = 0.84), Akt (p = 0.55), mTOR (p = 0.09), and p70S6K (p = 0.98). Skeletal muscle IGF-1 was significantly increased in LEU at 2 hours postexercise (p = 0.03) and 6 hours postexercise (p = 0.04) compared to PLC and UA. CONCLUSION: Three grams of l-leucine and ursolic acid had no effect on Akt/mTORC1 signaling or serum insulin or IGF-1; however, l-leucine increased skeletal muscle IGF-1 concentration in resistance-trained men.

Daily Overfeeding from Protein and/or Carbohydrate Supplementation for Eight Weeks in Conjunction with Resistance Training Does not Improve Body Composition and Muscle Strength or Increase Markers Indicative of Muscle Protein Synthesis and Myogenesis in Resistance-Trained Males.

This study determined the effects of heavy resistance training and daily overfeeding with carbohydrate and/or protein on blood and skeletal muscle markers of protein synthesis (MPS), myogenesis, body composition, and muscle performance. Twenty one resistance-trained males were randomly assigned to either a protein + carbohydrate [HPC (n = 11)] or a carbohydrate [HC (n = 10)] supplement group in a double-blind fashion. Body composition and muscle performance were assessed, and venous blood samples and muscle biopsies were obtained before and after eight weeks of resistance training and supplementation. Data were analyzed by two-way ANOVA (p ≤ 0.05). Total body mass, body water, and fat mass were significantly increased in both groups in response to resistance training, but not supplementation (p < 0.05); however, lean mass was not significantly increased in either group (p = 0.068). Upper- (p = 0.024) and lower-body (p = 0.001) muscle strength and myosin heavy chain (MHC) 1 (p = 0.039) and MHC 2A (p = 0.027) were also significantly increased with resistance training. Serum IGF-1, GH, and HGF were not significantly affected (p > 0.05). Muscle total DNA, total protein, and c-Met were not significantly affected (p > 0.05). In conjunction with resistance training, the peri-exercise and daily overfeeding of protein and/or carbohydrate did not preferentially improve body composition, muscle performance, and markers indicative of MPS and myogenic activation. Key pointsIn response to 56 days of heavy resistance training and HC or HPC supplementation, similar increases in muscle mass and strength in both groups occurred; however, the increases were not different between supplement groups.The supplementation of HPC had no preferential effect on augmenting serum IGF-1 GH, or HGF.The supplementation of HPC had no preferential effect on augmenting increases in total muscle protein content or the myogenic markers, total DNA and muscle cMet content.In response to 56 days of a daily supplemental dose of 94 g of protein and 196 g of carbohydrate, the HPC group was no more effective than 312 g of carbohydrate in the HC group in increasing muscle strength and mass due to its ability to elevate serum anabolic hormones and growth factors and markers of myogenic activation of satellite cells.

Acute Myosin Heavy Chain Isoform mRNA Expression in Response to Two Resistance Exercise Intensities With Equal Volume Load in Resistance-Trained Men.

The purpose of this study was to determine if resistance exercise intensity, in the context of equal volume load, differentially affected myosin heavy chain (MHC) isoform messenger RNA (mRNA) expression in resistance-trained men. In a crossover, uniform-balanced design, 10 male participants (23.7 ± 2.8 years, 178.8 ± 5.9 cm, 85.9 ± 9.2 kg) completed 2 lower-body resistance exercise sessions of different intensities with equal volume load. For the higher-intensity exercise session, participants performed 5 sets of 6 repetitions at 80% of 1 repetition maximum (1RM). For the lower-intensity exercise session, participants performed 3 sets of 16 repetitions at 50% of 1RM. Muscle samples from the vastus lateralis were acquired before exercise (PRE), 45 minutes postexercise (45MINPE), 3 hours postexercise (3HRPE), 24 hours postexercise (24HRPE), and 48 hours postexercise (48HRPE). Statistical analyses of mRNA expression were performed using separate 2 × 5 two-way repeated-measures analyses of variance for each criterion variable (p ≤ 0.05). There were no statistically significant interactions between intensity and time. Likewise, there were no significant differences between exercise intensity in MHC expression. Expression of mRNA for all MHC isoforms decreased at all postexercise time points, except 3HRPE (p = 0.051), compared with PRE following both exercise bouts (p ≤ 0.05). The results of this study found no difference in mRNA expression of MHC isoforms as a function of resistance exercise intensity. In addition, in contrast to results found in previous studies of untrained men, MHC mRNA expression seems to decrease in response to acute resistance exercise in previously resistance-trained men.

Heavy resistance training and peri-exercise ingestion of a multi-ingredient ergogenic nutritional supplement in males: effects on body composition, muscle performance and markers of muscle protein synthesis.

This study determined the effects of heavy resistance training and peri-exercise ergogenic multi-ingredient nutritional supplement ingestion on blood and skeletal markers of muscle protein synthesis (MPS), body composition, and muscle performance. Twenty-four college-age males were randomly assigned to either a multi-ingredient SizeOn Maximum Performance (SIZE) or protein/carbohydrate/creatine (PCC) comparator supplement group in a double-blind fashion. Body composition and muscle performance were assessed, and venous blood samples and muscle biopsies were obtained before and after 6 weeks of resistance training and supplementation. Data were analyzed by 2-way ANOVA (p ≤ 0.05). Total body mass, body water, and fat mass were not differentially affected (p > 0.05). However, fat-free mass was significantly increased in both groups in response to resistance training (p = 0.037). Lower-body muscle strength (p = 0.029) and endurance (p = 0.027) were significantly increased with resistance training, but not supplementation (p > 0.05). Serum insulin, IGF-1, GH, and cortisol were not differentially affected (p > 0.05). Muscle creatine content was significantly increased in both groups from supplementation (p = 0.044). Total muscle protein (p = 0.038), MHC 1 (p = 0.041), MHC 2A, (p = 0.029), total IRS- (p = 0.041), and total Akt (p = 0.011) were increased from resistance training, but not supplementation. In response to heavy resistance training when compared to PCC, the peri-exercise ingestion of SIZE did not preferentially improve body composition, muscle performance, and markers indicative of MPS. Key pointsIn response to 42 days of heavy resistance training and either SizeOn Maximum Performance or protein/carbohydrate/creatine supplementation, similar increases in muscle mass and strength in both groups occurred; however, the increases were not different between supplement groups.The supplementation of SizeOn Maximum Performance had no preferential effect on augmenting serum insulin, IGF-1, and GH, or in decreasing cortisol.While resistance training was effective in increasing total creatine content in skeletal muscle, myofibrillar protein, and the content of total IRS-1 and Akt, it was not preferentially due to SizeOn Maximum Performance supplementation.At the daily dose of 50 g, SizeOn Maximum Performance supplementation for 42 days combined with resistance training does not increases muscle mass and strength due to its ability to elevate serum hormones and growth factors or in its ability to augment skeletal muscle signaling pathway markers indicative of muscle protein synthesis when compared to an equivalent daily dose of protein/carbohydrate/creatine.

Heavy Resistance Training and Supplementation With the Alleged Testosterone Booster Nmda has No Effect on Body Composition, Muscle Performance, and Serum Hormones Associated With the Hypothalamo-Pituitary-Gonadal Axis in Resistance-Trained Males.

The effects of 28 days of heavy resistance training while ingesting the alleged testosterone-boosting supplement, NMDA, were determined on body composition, muscle strength, serum cortisol, prolactin, and hormones associated with the hypothalamo-pituitary- gonadal (HPG) axis. Twenty resistance-trained males engaged in 28 days of resistance training 4 times/wk while orally ingesting daily either 1.78 g of placebo (PLAC) or NMDA. Data were analyzed with separate 2 x 2 ANOVA (p < 0.05). Criterion measures involved body composition, muscle strength, serum cortisol, prolactin, and gonadal hormone levels [free and total testosterone, luteininzing hormome (LH), gonadotrophin releasing hormone (GnRH), estradiol], and were assessed before (Day 0) and after (Day 29) resistance training and supplementation. No changes were noted for total body water and fat mass in response to resistance training (p > 0.05) or supplementation (p > 0.05). In regard to total body mass and fat-free mass, however, each was significantly increased in both groups in response to resistance training (p < 0.05), but were not affected by supplementation (p > 0.05). In both groups, lower-body muscle strength was significantly increased in response to resistance training (p < 0.05); however, supplementation had no effect (p > 0.05). All serum hormones (total and free testosterone, LH, GnRH, estradiol, cortisol, prolactin) were unaffected by resistance training (p > 0.05) or supplementation (p > 0.05). The gonadal hormones and cortisol and prolactin were unaffected by 28 days of NMDA supplementation and not associated with the observed increases in muscle strength and mass. At the dose provided, NMDA had no effect on HPG axis activity or ergogenic effects in skeletal muscle. Key PointsIn response to 28 days of heavy resistance training and NMDA supplementation, similar increases in muscle mass and strength in both groups occurred; however, the increases were not different between supplement groups.The supplementation of NMDA had no preferential effect on augmenting testosterone or decreasing estrogen, cortisol, and prolactin.While resistance training was effective in increasing muscle mass and strength, it was not preferentially due to NMDA supplementation.At the dose provided, NMDA supplementation for 28 days combined with resistance training does not increases muscle mass and strength due to its ability to elevate endogenous testosterone levels and lower cortisol and prolactin when compared to placebo.

The effects of 8 weeks of heavy resistance training and branched-chain amino acid supplementation on body composition and muscle performance.

PURPOSE: This study determined the effects of 8 weeks of heavy resistance training combined with branched-chain amino acid (BCAA) supplementation on body composition and muscle performance. METHODS: Resistance training was performed by 19 non-resistance-trained males (three sets of 8-10 repetitions) four times/week, for 8 weeks, while also ingesting 9 g/day of BCAA or 9 g/day of placebo (PLAC) on the exercise days only (one-half of total dose 30 min before and after exercise). Data were analyzed with separate 2 × 2 analysis of variance (ANOVA) (p < 0.05). RESULTS: For total body mass, neither group significantly increased with training (p = 0.593) and also, there were no significant changes in total body water (p = 0.517). In addition, no training- or supplement-induced (p = 0.783) changes occurred with fat mass or fat-free mass (p = 0.907). Upper-body (p = 0.047) and lower-body strength (p = 0.044) and upper- (p = 0.001) and lower-body muscle endurance (p = 0.013) increased with training; however, these increases were not different between the groups (p > 0.05). CONCLUSION: When combined with heavy resistance training for 8 weeks, supplementation with 9 g/day of BCAA 30 min before and after exercise had no preferential effects on body composition and muscle performance.

Effect of resistance exercise intensity on the expression of PGC-1α isoforms and the anabolic and catabolic signaling mediators, IGF-1 and myostatin, in human skeletal muscle.

The purpose of this study was to investigate the acute messenger (mRNA) expression of the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) isoforms, insulin-like growth factor-1Ea (IGF-1Ea), and myostatin in response to 2 resistance exercise intensities. In a uniform-balanced, crossover design, 10 participants performed 2 separate testing sessions involving a lower body resistance exercise component consisting of a lower intensity (50% of 1-repetition maximum; 1RM) protocol and a higher intensity (80% of 1RM) protocol of equal volumes. Muscle samples were obtained at before exercise, 45 min, 3 h, 24 h, and 48 h postexercise. Resistance exercise did not alter total PGC-1α mRNA expression; however, distinct responses of each PGC-1α isoform were observed. The response of each isoform was consistent between sessions, suggesting no effect of resistance exercise intensity on the complex transcriptional expression of the PGC-1α gene. IGF-1Ea mRNA expression significantly increased following the higher intensity session compared with pre-exercise and the lower intensity session. Myostatin mRNA expression was significantly reduced compared with pre-exercise values at all time points with no difference between exercise intensity. Further research is needed to determine the effects of the various isoforms of PGC-1α in human skeletal muscle on the translational level as well as their relation to the expression of IGF-1 and myostatin.

Upper-body resistance exercise augments vastus lateralis androgen receptor-DNA binding and canonical Wnt/ß-catenin signaling compared to lower-body resistance exercise in resistance-trained men without an acute increase in serum testosterone.

The purpose of the study was to determine the effect of single bouts of lower-body (LB) and upper- and lower-body (ULB) resistance exercise on serum testosterone concentrations and the effects on muscle testosterone, dihydrotestosterone (DHT), androgen receptor (AR) protein content, and AR-DNA binding. A secondary purpose was to determine the effects on serum wingless-type MMTV integration site (Wnt4) levels and skeletal muscle ß-catenin content. In a randomized cross-over design, exercise bouts consisted of a LB and ULB protocol, and each bout was separated by 1 week. Blood and muscle samples were obtained before exercise and 3 and 24h post-exercise; blood samples were also obtained at 0.5, 1, and 2 h post-exercise. Statistical analyses were performed by separate two-way factorial analyses of variance (ANOVA) with repeated measures. No significant differences from baseline were observed in serum total and free testosterone and skeletal muscle testosterone and DHT with either protocol (p>0.05). AR protein was significantly increased at 3 h post-exercise and decreased at 24 h post-exercise for ULB, whereas AR-DNA binding was significantly increased at 3 and 24h post-exercise (p<0.05). In response to ULB, serum Wnt4 was significantly increased at 0.5, 1, and 2 h post-exercise (p<0.05) and ß-catenin was significantly increased at 3 and 24 h post-exercise (p<0.05). It was concluded that, despite a lack of increase in serum testosterone and muscle androgen concentrations from either mode of resistance exercise, ULB resistance exercise increased Wnt4/ß-catenin signaling and AR-DNA binding.

Capsaicin and evodiamine ingestion does not augment energy expenditure and fat oxidation at rest or after moderately-intense exercise.

Capsaicin and evodiamine are 2 thermogenic agents recognized for their ability to stimulate the sympathetic nervous system. We hypothesized that both capsaicin and evodiamine would be effective at increasing thermogenesis and lipid oxidation during rest and exercise. In a randomized, cross-over design, 11 men ingested 500 mg of cayenne pepper (1.25 mg capsaicin), 500 mg evodiamine, or placebo at rest following 30 minutes of energy expenditure assessment using open-circuit spirometry. Energy expenditure was assessed again prior to commencing approximately 30 minutes of treadmill exercise at 65% peak oxygen consumption. Energy expenditure was assessed for another 30 minutes of the post-exercise period. Heart rate, blood pressure, core temperature, and venous blood samples were obtained 30 minutes before supplement ingestion, 1 hour after supplement ingestion, immediately post-exercise, and 45 minutes post-exercise. Serum markers of lipid oxidation (glycerol, free fatty acids, glucose, epinephrine, and norepinephrine) were determined spectrophotometrically with enzyme-linked immunosorbent assay. Two-way analyses of variance with repeated measures were performed for each dependent variable (P ≤ .05) with Supplement and Test as main effects. Statistical analyses revealed significant main effects for Test for hemodynamics, energy expenditure, serum catecholamines, and markers of fat oxidation immediately post-exercise (P < .05). No significant interactions between Supplement and Test were noted for any criterion variable (P > .05). These results suggest that acute ingestion of 500 mg of cayenne (1.25 mg capsaicin) or evodiamine is not effective at inducing thermogenesis and increasing fat oxidation at rest or during exercise in men.

Effects of 28 days of resistance exercise while consuming commercially available pre- and post-workout supplements, NO-Shotgun® and NO-Synthesize® on body composition, muscle strength and mass, markers of protein synthesis, and clinical safety markers in males.

PURPOSE: The effects of 28 days of heavy resistance training while ingesting the pre- and post-workout supplements, NO-Shotgun® and NO-Synthesize® were determined on body composition, muscle strength and mass, markers of protein synthesis, and clinical safety markers. METHODS: Nineteen non-resistance-trained males participated in a resistance training program 4 times/week for 28 days while either ingesting 27 g/day of carbohydrate (CARB) or NO-Shotgun® 30 min pre-exercise and 27 g/day of carbohydrate or NO- Synthesize® 30 min post-exercise (NOSS). Data were analyzed with separate 2 × 2 ANOVA (p < 0.05). RESULTS: Total body mass was increased in both groups (p = 0.001), but not different between groups. Fat mass was unchanged with CARB, but NOSS decreased fat mass (p = 0.026). Both groups increased fat-free mass (p = 0.001); however, the increases were greater with NOSS (p = 0.023). NOSS underwent greater increases in upper-body (p = 0.023) and lower-body (p = 0.035) strength than CARB. Myofibrillar protein significantly increased in both groups (p = 0.041), with NOSS being greater than CARB (p = 0.049). All of the MHC isoforms were significantly increased in both groups; however, NOSS was greater than CARB for MHC 1 (p = 0.013) and MHC 2A (p = 0.046). All of the myogenic regulatory factors were significantly increased in both groups; however, NOSS was greater than CARB for Myo-D (p = 0.038) and MRF-4 (p = 0.001). For the whole blood and serum clinical chemistry markers, all variables remained within normal clinical ranges. CONCLUSIONS: Heavy resistance training for 28 days, with NO-Shotgun® and NO-Synthesize® ingested before and after exercise, respectively, significantly improved body composition and increased muscle mass and performance without abnormally impacting any of the clinical chemistry markers.

The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels.

Numerous creatine formulations have been developed primarily to maximize creatine absorption. Creatine ethyl ester is alleged to increase creatine bio-availability. This study examined how a seven-week supplementation regimen combined with resistance training affected body composition, muscle mass, muscle strength and power, serum and muscle creatine levels, and serum creatinine levels in 30 non-resistance-trained males. In a double-blind manner, participants were randomly assigned to a maltodextrose placebo (PLA), creatine monohydrate (CRT), or creatine ethyl ester (CEE) group. The supplements were orally ingested at a dose of 0.30 g/kg fat-free body mass (approximately 20 g/day) for five days followed by ingestion at 0.075 g/kg fat free mass (approximately 5 g/day) for 42 days. Results showed significantly higher serum creatine concentrations in PLA (p = 0.007) and CRT (p = 0.005) compared to CEE. Serum creatinine was greater in CEE compared to the PLA (p = 0.001) and CRT (p = 0.001) and increased at days 6, 27, and 48. Total muscle creatine content was significantly higher in CRT (p = 0.026) and CEE (p = 0.041) compared to PLA, with no differences between CRT and CEE. Significant changes over time were observed for body composition, body water, muscle strength and power variables, but no significant differences were observed between groups. In conclusion, when compared to creatine monohydrate, creatine ethyl ester was not as effective at increasing serum and muscle creatine levels or in improving body composition, muscle mass, strength, and power. Therefore, the improvements in these variables can most likely be attributed to the training protocol itself, rather than the supplementation regimen.