Effect of Whey Protein Quality on Physiological Response to Chronic Resistance Exercise in Trained Men: A Double-Blind, Placebo-Controlled, Randomized Trial

Acute studies have revealed that insulin and possibly incretin hormone [e.g., glucagon-like peptide-1 (GLP-1)] response in humans is significantly affected by whey protein (WP) form [e.g., whey protein isolate (WPI) versus hydrolysate (WPH)], whereas extensive hydrolysates of casein protein, versus native casein, were recently shown to promote a potentially greater (p=0.10) acute muscle protein synthesis response. Similarly, fractions and specific peptides from WP have been identified that may potentiate exercise recovery and/or the muscle protein synthesis response from heavy resistance training. However, to date, no study has compared the chronic effects WP form or molecular distribution may have when consumed in combination with heavy resistance training. PURPOSE: Therefore, the primary purpose of this investigation was to compare the effects of three different variations of a WP on the physiological response to weight training in previously resistance trained, healthy males. METHODS: Fifty-six resistance trained men (21.40±0.36 yrs; 79.46±1.04 kg; 178.59±0.66 cm; 1.24±0.03 1RM bench press-to-body mass ratio) were randomly assigned to receive one of four double-blinded treatments: 30 g/serving carbohydrate (PLA) or 30 g/serving protein from either a) 80% whey protein concentrate (WPC80), b) high lactoferrin containing 80% WPC (WPC80+), or c) extensively hydrolyzed WPC80 (WPH). All subjects participated in eight weeks of a split-body, linear periodized resistance training program, and consumed two servings of treatment per day (one immediately pre- and post-exercise on training days; twice between meals on non-training days). Body composition, upper- and lower-body strength [1RM Bench Press (1RM BP) and 1RM Hack Squat (1RM HS), respectively] and anaerobic endurance [80% of 1RM for maximal repetitions (80RM BP and 80RM HS, respectively)], and fasted blood measures were assessed before (PRE) and after (POST) the 8-week intervention. Twenty-four hour muscle damage (CK) and immune (WBC) response to lower-body resistance training was assessed during Week 1 and 8. Also, total repetitions to failure, CK and WBC were assessed during POST, prior to and in response to repeated daily (x3) bouts of 80RM HS. Two-way repeated measures ANCOVAs were used for statistical analyses. Significance was set at &alpha; = 0.05. RESULTS: No significant differences (p>0.05) were observed between groups for total training volume (kg/min), or relative energy (kcals/kg/d), protein (g/kg/d), carbohydrate (g/kg/d), or lipid (g/kg/d) during the 8-week intervention. All groups increased (p0.05) between-group effects were observed. For repeated 80RM HS tests, only WPC80+ realized a significant difference for total repetitions completed between any of the three days of testing (+15.56% more repetitions for 80RM24 versus 80RMPOST; p0.05 and p>0.0125, respectively) changes were observed for 12-hour fasted blood lipids, glucose, WBC or CK from PRE to POST; however, all groups reduced (p0.05) for either CK or WBC. Lean body mass and total body muscle mass increased (p<0.0125) in all groups, as did body mass in all groups except WPH (+0.641 kg; p=0.114). However, WPH realized a significant PRE to POST reduction in fat mass (-5.942%) and percent body fat (-1.601%), which was significantly different (p<0.05) from PLA (+9.100% and +0.640%, respectively). CONCLUSION: In previously trained, college-aged men, 60 g/d of WPC80, WPC80+, WPH or PLA provide similar responses to an 8-week heavy resistance training program on measures of total body muscle mass, strength, anaerobic endurance and blood lipids. However, WPH appears to significantly augment lipolysis and may increase nitrogen retention

Effect of protein/essential amino acids and resistance training on skeletal muscle hypertrophy: A case for whey protein

Regardless of age or gender, resistance training or provision of adequate amounts of dietary protein (PRO) or essential amino acids (EAA) can increase muscle protein synthesis (MPS) in healthy adults. Combined PRO or EAA ingestion proximal to resistance training, however, can augment the post-exercise MPS response and has been shown to elicit a greater anabolic effect than exercise plus carbohydrate. Unfortunately, chronic/adaptive response data comparing the effects of different protein sources is limited. A growing body of evidence does, however, suggest that dairy PRO, and whey in particular may: 1) stimulate the greatest rise in MPS, 2) result in greater muscle cross-sectional area when combined with chronic resistance training, and 3) at least in younger individuals, enhance exercise recovery. Therefore, this review will focus on whey protein supplementation and its effects on skeletal muscle mass when combined with heavy resistance training.peerReviewe

Minimal nutrition intervention with high-protein/low-carbohydrate and low-fat, nutrient-dense food supplement improves body composition and exercise benefits in overweight adults: A randomized controlled trial

Background: Exercise and high-protein/reduced-carbohydrate and -fat diets have each been shown separately, or in combination with an energy-restricted diet to improve body composition and health in sedentary, overweight (BMI > 25) adults. The current study, instead, examined the physiological response to 10 weeks of combined aerobic and resistance exercise (EX) versus exercise + minimal nutrition intervention designed to alter the macronutrient profile, in the absence of energy restriction, using a commercially available high-protein/low-carbohydrate and low-fat, nutrient-dense food supplement (EXFS); versus control (CON). Methods: Thirty-eight previously sedentary, overweight subjects (female = 19; male = 19) were randomly assigned to either CON (n = 10), EX (n = 14) or EXFS (n = 14). EX and EXFS participated in supervised resistance and endurance training (2× and 3×/wk, respectively); EXFS consumed 1 shake/d (weeks 1 and 2) and 2 shakes/d (weeks 3–10). Results: EXFS significantly decreased total energy, carbohydrate and fat intake (-14.4%, -27.2% and -26.7%, respectively; p < 0.017), and increased protein and fiber intake (+52.1% and +21.2%, respectively; p < 0.017). EX and EXFS significantly decreased fat mass (-4.6% and -9.3%, respectively; p < 0.017), with a greater (p < 0.05) decrease in EXFS than EX and CON. Muscle mass increase only reached significance in EXFS (+2.3%; p < 0.017), which was greater (p < 0.05) than CON but not EX (+1.1%). Relative VO2max improved in both exercise groups (EX = +5.0% and EXFS = +7.9%; p < 0.017); however, only EXFS significantly improved absolute VO2max (+6.2%; p = 0.001). Time-to-exhaustion during treadmill testing increased in EX (+9.8%) but was significantly less (p < 0.05) than in EXFS (+21.2%). Total cholesterol and LDL decreased only in the EXFS (-12.0% and -13.3%, respectively; p < 0.017). Total cholesterol-to-HDL ratio, however, decreased significantly (p < 0.017) in both exercise groups. Conclusion: Absent energy restriction or other dietary controls, provision of a high-protein/low-carbohydrate and -fat, nutrient-dense food supplement significantly, 1) modified ad libitum macronutrient and energy intake (behavior effect), 2) improved physiological adaptations to exercise (metabolic advantage), and 3) reduced the variability of individual responses for fat mass, muscle mass and time-to-exhaustion – all three variables improving in 100% of EXFS subjects

Beta-alanine supplementation and high-intensity interval training augments metabolic adaptations and endurance performance in college-aged men

A randomized, double-blind, placebo-controlled study was conducted to evaluate the effects β-alanine supplementation and high-intensity interval training (HIIT) on endurance performance

Pre-workout consumption of Celsius® enhances the benefits of chronic exercise on body composition and cardiorespiratory fitness

The functional beverage Celsius®, has recently been shown, after acute and chronic (28 days) consumption, to increase resting metabolism and serum blood markers of lipolysis in healthy, college-aged men and women. The purpose of this study was to examine the combined effects of a 10-week exercise program while consuming Celsius® on body composition and cardiorespiratory fitness changes in sedentary men and women

Effects of β-alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial

Background: Intermittent bouts of high-intensity exercise result in diminished stores of energy substrates, followed by an accumulation of metabolites, promoting chronic physiological adaptations. In addition, β-alanine has been accepted has an effective physiological hydrogen ion (H+) buffer. Concurrent high-intensity interval training (HIIT) and β-alanine supplementation may result in greater adaptations than HIIT alone. The purpose of the current study was to evaluate the effects of combining β-alanine supplementation with high-intensity interval training (HIIT) on endurance performance and aerobic metabolism in recreationally active college-aged men. Methods: Forty-six men (Age: 22.2 ± 2.7 yrs; Ht: 178.1 ± 7.4 cm; Wt: 78.7 ± 11.9; VO2peak: 3.3 ± 0.59 l·min-1) were assessed for peak O2 utilization (VO2peak), time to fatigue (VO2TTE), ventilatory threshold (VT), and total work done at 110% of pre-training VO2peak (TWD). In a double-blind fashion, all subjects were randomly assigned into one either a placebo (PL – 16.5 g dextrose powder per packet; n = 18) or β-alanine (BA – 1.5 g β-alanine plus 15 g dextrose powder per packet; n = 18) group. All subjects supplemented four times per day (total of 6 g/day) for the first 21-days, followed by two times per day (3 g/day) for the subsequent 21 days, and engaged in a total of six weeks of HIIT training consisting of 5–6 bouts of a 2:1 minute cycling work to rest ratio. Results: Significant improvements in VO2peak, VO2TTE, and TWD after three weeks of training were displayed (p \u3c 0.05). Increases in VO2peak, VO2TTE, TWD and lean body mass were only significant for the BA group after the second three weeks of training. Conclusion: The use of HIIT to induce significant aerobic improvements is effective and efficient. Chronic BA supplementation may further enhance HIIT, improving endurance performance and lean body mass

Effects of β-alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial

Background: Intermittent bouts of high-intensity exercise result in diminished stores of energy substrates, followed by an accumulation of metabolites, promoting chronic physiological adaptations. In addition, β-alanine has been accepted has an effective physiological hydrogen ion (H+) buffer. Concurrent high-intensity interval training (HIIT) and β-alanine supplementation may result in greater adaptations than HIIT alone. The purpose of the current study was to evaluate the effects of combining β-alanine supplementation with high-intensity interval training (HIIT) on endurance performance and aerobic metabolism in recreationally active college-aged men. Methods: Forty-six men (Age: 22.2 ± 2.7 yrs; Ht: 178.1 ± 7.4 cm; Wt: 78.7 ± 11.9; VO2peak: 3.3 ± 0.59 l·min-1) were assessed for peak O2 utilization (VO2peak), time to fatigue (VO2TTE), ventilatory threshold (VT), and total work done at 110% of pre-training VO2peak (TWD). In a double-blind fashion, all subjects were randomly assigned into one either a placebo (PL – 16.5 g dextrose powder per packet; n = 18) or β-alanine (BA – 1.5 g β-alanine plus 15 g dextrose powder per packet; n = 18) group. All subjects supplemented four times per day (total of 6 g/day) for the first 21-days, followed by two times per day (3 g/day) for the subsequent 21 days, and engaged in a total of six weeks of HIIT training consisting of 5–6 bouts of a 2:1 minute cycling work to rest ratio. Results: Significant improvements in VO2peak, VO2TTE, and TWD after three weeks of training were displayed (p < 0.05). Increases in VO2peak, VO2TTE, TWD and lean body mass were only significant for the BA group after the second three weeks of training. Conclusion: The use of HIIT to induce significant aerobic improvements is effective and efficient. Chronic BA supplementation may further enhance HIIT, improving endurance performance and lean body mass

Prioritising surveillance for alien organisms transported as stowaways on ships travelling to South Africa

The global shipping network facilitates the transportation and introduction of marine and terrestrial organisms to regions where they are not native, and some of these organisms become invasive. South Africa was used as a case study to evaluate the potential for shipping to contribute to the introduction and establishment of marine and terrestrial alien species (i.e. establishment debt) and to assess how this varies across shipping routes and seasons. As a proxy for the number of species introduced (i.e. 'colonisation pressure') shipping movement data were used to determine, for each season, the number of ships that visited South African ports from foreign ports and the number of days travelled between ports. Seasonal marine and terrestrial environmental similarity between South African and foreign ports was then used to estimate the likelihood that introduced species would establish. These data were used to determine the seasonal relative contribution of shipping routes to South Africa's marine and terrestrial establishment debt. Additionally, distribution data were used to identify marine and terrestrial species that are known to be invasive elsewhere and which might be introduced to each South African port through shipping routes that have a high relative contribution to establishment debt. Shipping routes from Asian ports, especially Singapore, have a particularly high relative contribution to South Africa's establishment debt, while among South African ports, Durban has the highest risk of being invaded. There was seasonal variation in the shipping routes that have a high relative contribution to the establishment debt of the South African ports. The presented method provides a simple way to prioritise surveillance effort and our results indicate that, for South Africa, port-specific prevention strategies should be developed, a large portion of the available resources should be allocated to Durban, and seasonal variations and their consequences for prevention strategies should be explored further. (Résumé d'auteur

RESEARCH Open Access

Herbal adaptogens combined with protein fractions from bovine colostrum and hen egg yolk reduce liver TNF-α expression and protein carbonylation in Western diet feeding in rat