This study compared a carbohydrate-, protein-, and ribose-containing repletion drink vs. carbohydrates alone during 8 weeks of aerobic training. Thirty-two men (age, mean ± SD = 23 ± 3 years) performed tests for aerobic capacity (V(O2)peak), time to exhaustion (TTE) at 90% V(O2)peak, and percent body fat (%fat), and fat-free mass (FFM). Testing was conducted at pre-training (PRE), mid-training at 3 weeks (MID3), mid-training at 6 weeks (MID6), and post-training (POST). Cycle ergometry training was performed at 70% V(O2)peak for 1 hours per day, 5 days per week for 8 weeks. Participants were assigned to a test drink (TEST; 370 kcal, 76 g carbohydrate, 14 g protein, 2.2 g d-ribose; n = 15) or control drink (CON; 370 kcal, 93 g carbohydrate; n = 17) ingested immediately after training. Body weight (BW; 1.8% decrease CON; 1.3% decrease TEST from PRE to POST), %fat (5.5% decrease CON; 3.9% decrease TEST), and FFM (0.1% decrease CON; 0.6% decrease TEST) decreased (p ≤ 0.05), whereas V(O2)peak (19.1% increase CON; 15.8% increase TEST) and TTE (239.1% increase CON; 377.3% increase TEST) increased (p ≤ 0.05) throughout the 8 weeks of training. Percent decreases in %fat from PRE to MID3 and percent increases in FFM from PRE to MID3 and MID6 were greater (p ≤ 0.05) for TEST than CON. Overall, even though the TEST drink did not augment BW, V(O2)peak, or TTE beyond carbohydrates alone, it did improve body composition (%fat and FFM) within the first 3-6 weeks of supplementation, which may be helpful for practitioners to understand how carbohydrate-protein recovery drinks can and cannot improve performance in their athletes.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to examine the effect of β-hydroxy-β-methylbutyrate (HMB-FA) and cold water immersion (CWI) on circulating concentrations of tumor necrosis factor alpha (TNF-α) and monocyte TNF-α receptor (TNFR1) expression. Forty resistance trained men (22.3 ± 2.4 y) were randomized into four groups (Placebo = PL, HMB-FA, CWI, and HMB-FA-CWI) and performed an acute intense exercise protocol (4 sets of up to 10 repetitions of the squat, dead lift, and split squat). Participants also performed 4 sets of up to 10 repetitions of the squat at 24 and 48 hours following the initial exercise bout. Blood was sampled at PRE, immediately post (IP), 30-minutes post (30P), 24 hours post (24P), and 48 hours post (48P) exercise. Circulating TNF-α was assayed and TNFR1 expression on CD14+ monocytes was measured by flow cytometry. The exercise protocol significantly elevated TNF-α in only PL (p = 0.006) and CWI (p = 0.045) at IP. Mean percent changes show TNF-α significantly increased from PRE to IP for only PL and CWI groups (p < 0.05) while the percent change of TNF-α for HMB-FA and HMB-FA-CWI was not significant. TNFR1 receptor expression was elevated in PL (p = 0.023) and CWI (p = 0.02) at 30P compared to PRE while both HMB-FA treated groups did not increase significantly. In conclusion, HMB-FA supplementation attenuated circulating TNF-α immediately post-exercise and TNFR1 expression during recovery compared to PL and CWI treatment. Our data suggest that HMB-FA supplementation may attenuate the initial immune response to intense exercise.
[Show abstract][Hide abstract] ABSTRACT: Background
Performing regular exercise is known to manifest a number of health benefits that mainly relate to cardiovascular and muscular adaptations to allow for greater oxygen extraction and utilization. There is increasing evidence that nutrient intake can affect the adaptive response to a single exercise bout, and that protein feeding is important to facilitate this process. Thus, the exercise-nutrient interaction may potentially lead to a greater response to training. The role of post-exercise protein ingestion in enhancing the effects of running-based endurance exercise training relative to energy-matched carbohydrate intervention remains to be established. Additionally, the influence of immediate versus overnight protein ingestion in mediating these training effects is currently unknown. The current protocol aims to establish whether post-exercise nutrient intake and timing would influence the magnitude of improvements during a prescribed endurance training program.
The project involves two phases with each involving two treatment arms applied in a randomized investigator-participant double-blind parallel group design. For each treatment, participants will be required to undergo six weeks of running-based endurance training. Immediately post-exercise, participants will be prescribed solutions providing 0.4 grams per kilogram of body mass (g · kg−1) of whey protein hydrolysate plus 0.4 g · kg−1 sucrose, relative to an isocaloric sucrose control (0.8 g · kg−1; Phase I). In Phase II, identical protein supplements will be provided (0.4 + 0.4 g · kg−1 · h−1 of whey protein hydrolysate and sucrose, respectively), with the timing of ingestion manipulated to compare immediate versus overnight recovery feedings. Anthropometric, expired gas, venous blood and muscle biopsy samples will be obtained at baseline and following the six-week training period.
By investigating the role of nutrition in enhancing the effects of endurance exercise training, we will provide novel insight regarding nutrient-exercise interactions and the potential to help and develop effective methods to maximize health or performance outcomes in response to regular exercise.
Current Controlled Trials registration number: ISRCTN27312291 (date assigned: 4 December 2013). The first participant was randomized on 11 December 2013.
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