Independent and combined effets of liquid carbohydrate/essential amino acid ingestion on hormonal and muscular adaptations following resistance training in untrained men

School of Human Movement Studies, Charles Sturt University, Allen House 2.13, Bathurst, NSW, Australia.
Arbeitsphysiologie (Impact Factor: 2.19). 05/2006; 97(2):225-38. DOI: 10.1007/s00421-005-0127-z
Source: PubMed


This investigation examined chronic alteration of the acute hormonal response associated with liquid carbohydrate (CHO) and/or essential amino acid (EAA) ingestion on hormonal and muscular adaptations following resistance training. Thirty-two untrained young men performed 12 weeks of resistance training twice a week, consuming ~675 ml of either, a 6% CHO solution, 6 g EAA mixture, combined CHO + EAA supplement or placebo (PLA). Blood samples were obtained pre- and post-exercise (week 0, 4, 8, and 12), for determination of glucose, insulin, and cortisol. 3-Methylhistidine excretion and muscle fibre cross-sectional area (fCSA) were determined pre- and post-training. Post-exercise cortisol increased (P<0.05) during each training phase for PLA. No change was displayed by EAA; CHO and CHO + EAA demonstrated post-exercise decreases (P<0.05). All groups displayed reduced pre-exercise cortisol at week 12 compared to week 0 (P<0.05). Post-exercise insulin concentrations showed no change for PLA; increases were observed for the treatment groups (P<0.05), which remained greater for CHO and CHO + EAA (P<0.001) than PLA. EAA and CHO ingestion attenuated 3-methylhistidine excretion 48 h following the exercise bout. CHO + EAA resulted in a 26% decrease (P<0.01), while PLA displayed a 52% increase (P<0.01). fCSA increased across groups for type I, IIa, and IIb fibres (P<0.05), with CHO + EAA displaying the greatest gains in fCSA relative to PLA (P<0.05). These data indicate that CHO + EAA ingestion enhances muscle anabolism following resistance training to a greater extent than either CHO or EAA consumed independently. The synergistic effect of CHO + EAA ingestion maximises the anabolic response presumably by attenuating the post-exercise rise in protein degradation.

    • "Notwithstanding, and in spite of the aforementioned studies that have clearly demonstrated exercise with or without nutritional provision acutely enhances MPS through translational efficiency, sparse literature to our knowledge has examined if resistance exercise with or without nutrient provision acutely enhances the expression of genes involved with ribosome biogenesis. Given that chronic provision with supplemental amino acids (chiefly LEU) (Bird et al. 2006) and WP (Burke et al. 2001; Cribb et al. 2006; Volek et al. 2013) with resistance exercise have been shown to increase muscle mass compared to resistance exercise alone, it stands to reason that the consumption of these nutrients following exercise may enhance the expression of genes associated with ribosome biogenesis . Therefore, the purpose of this study was to compare the post-exercise feeding effects of WP and LEU on markers of translational efficiency (i.e., MPS and mTOR pathway activity ) and ribosome biogenesis (i.e., nuclear/cytoplasmic/total RNA as well as the expression of 45S pre-rRNA and mRNAs related to ribosome processing, assembly, and nuclear export) 3 h following resistance exercise in rats. "
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    ABSTRACT: We compared immediate post-exercise whey protein (WP, 500 mg) versus L-leucine (LEU, 54 mg) feedings on skeletal muscle protein synthesis (MPS) mechanisms and ribosome biogenesis markers 3 h following unilateral plantarflexor resistance exercise in male, Wistar rats (~250 g). Additionally, in vitro experiments were performed on differentiated C2C12 myotubes to compare nutrient (i.e., WP, LEU) and 'exercise-like' treatments (i.e., caffeine, hydrogen peroxide, and AICAR) on ribosome biogenesis markers. LEU and WP significantly increased phosphorylated-rpS6 (Ser235/236) in the exercised (EX) leg 2.4-fold (P < 0.01) and 2.7-fold (P < 0.001) compared to the non-EX leg, respectively, whereas vehicle-fed control (CTL) did not (+65 %, P > 0.05). Compared to the non-EX leg, MPS levels increased 32 % and 52 % in the EX leg of CTL (P < 0.01) and WP rats (P < 0.001), respectively, but not in LEU rats (+15 %, P > 0.05). Several genes associated with ribosome biogenesis robustly increased in the EX versus non-EX legs of all treatments; specifically, c-Myc mRNA, Nop56 mRNA, Bop1 mRNA, Ncl mRNA, Npm1 mRNA, Fb1 mRNA, and Xpo-5 mRNA. However, only LEU significantly increased 45S pre-rRNA levels in the EX leg (63 %, P < 0.001). In vitro findings confirmed that 'exercise-like' treatments similarly altered markers of ribosome biogenesis, but only LEU increased 47S pre-rRNA levels (P < 0.01). Collectively, our data suggests that resistance exercise, as well as 'exercise-like' signals in vitro, acutely increase the expression of genes associated with ribosome biogenesis independent of nutrient provision. Moreover, while EX with or without WP appears superior for enhancing translational efficiency (i.e., increasing MPS per unit of RNA), LEU administration (or co-administration) may further enhance ribosome biogenesis over prolonged periods with resistance exercise.
    Amino Acids 10/2015; DOI:10.1007/s00726-015-2121-z · 3.29 Impact Factor
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    • "Over a longitudinal time frame when muscle protein synthesis is elevated from resistance exercise training and nutritional intake, the increase in lean body mass may be accompanied by a decrease in fat mass [1]. This was demonstrated in a recent study where essential amino acid-carbohydrate supplements were ingested in conjunction with 12 weeks of resistance training in young men [15]. In this study, those who consumed the essential amino acid-carbohydrate after resistance exercise showed greater increases in fat free mass and larger declines in fat mass compared to other subjects that consumed essential amino acids only, carbohydrate only, or a placebo after resistance exercise. "
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    ABSTRACT: Increasing the rate of muscle protein synthesis is an energy consuming process that explains the acute elevations in resting energy expenditure (REE) observed 12 to 72 hours after a resistance exercise session. We hypothesized that multiple sessions of resistance exercise combined with the intake of amino acids would increase REE and alter the nonprotein respiratory exchange ratio (RER). Ten male participants completed two separate seven-day trials where REE and RER were measured on each morning via indirect calorimetry. On four consecutive days within each seven-day trial, acute resistance exercise was performed, and nutritional intake was manipulated by providing (1) amino acids and carbohydrate (AA-RT) or (2) nonnitrogenous, isoenergetic carbohydrate (CHO-RT) before and during each resistance exercise session. Average REE within the training period was 3.61% greater in AA-RT (7897 ± 252 kJ) compared to CHO-RT (7622 ± 289 kJ; ). RER declined () from baseline after each resistance exercise was initiated in both AA-RT (0.82 ± 0.01 to 0.77 ± 0.01) and CHO-RT (0.82 ± 0.02 to 0.77 ± 0.02). We conclude the provision of amino acids with multiple bouts of resistance exercise enhances energy expenditure at rest without altering the utilization of lipid.
    05/2013; 2013. DOI:10.5402/2013/948695
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    • "Accordingly, a water volume of 8.5 mL/kg was used for intra-workout SUPP suspension. This approach to normalizing fluid ingestion between participants has been used previously by our laboratory [11] [20] [35]. As such, the during exercise SUPP serving was suspended in an average fluid volume of ~730 mL, which more accurately reflects the SUPP preparation practices of strength athletes in the field. "
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    ABSTRACT: We hypothesized that triphasic multinutrient supplementation during acute resistance exercise would enhance muscular performance, produce a more favorable anabolic profile, and reduce biochemical markers of muscle damage in strength-trained athletes. Fifteen male strength-trained athletes completed two acute lower-body resistance exercise sessions to fatigue 7 days apart. After a 4-hour fast, participants consumed either a multinutrient supplement (Musashi 1-2-3 Step System, Notting Hill, Australia) (SUPP) or placebo (PLA) beverage preexercise (PRE), during (DUR), and immediately postexercise (IP). Session volume loads were calculated as kilograms × repetitions. Lower-body peak power was measured using unloaded repeated countermovement jumps, and blood samples were collected to assess biochemistry, serum hormones, and muscle damage markers at PRE, DUR, IP, 30 minutes postexercise (P30), and 24 hours postexercise (P24h). The SUPP demonstrated increased glucose concentrations at DUR and IP compared with at PRE (P < .01), whereas PLA demonstrated higher glucose at P30 compared with at PRE (P < .001). Session volume load was higher for SUPP compared with PLA (P < .05). Cortisol increased at DUR, IP, and P30 compared with at PRE in both treatments (P < .05); however, SUPP also displayed lower cortisol at P24h compared with at PRE and PLA (P < .01). The total testosterone response to exercise was higher for PLA compared with SUPP (P < .01); however, total creatine kinase and C-reactive protein responses to exercise were lower for SUPP compared with PLA (P < .05). These data indicate that although triphasic multinutrient supplementation did not produce a more favorable anabolic profile, it improved acute resistance exercise performance while attenuating muscle damage in strength-trained athletes.
    Nutrition research 05/2013; 33(5):376-387. DOI:10.1016/j.nutres.2013.03.002 · 2.47 Impact Factor
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