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Human Muscle Protein Synthetic Responses during Weight-Bearing and Non-Weight-Bearing Exercise: A Comparative Study of Exercise Modes and Recovery Nutrition.

Pasiakos SM, McClung HL, Margolis LM, Murphy NE, Lin GG, Hydren JR, Young AJ - PLoS ONE (2015)

Bottom Line: Mixed-muscle and sarcoplasmic MPS were higher in recovery for LC than CE (mode main effect, P < 0.05).No other differences or interactions (mode x drink) were observed.These data show that, although whole-body protein turnover responses to absolute VO2-matched LC and CE are the same, LC elicited a greater muscle protein synthetic response than CE.

View Article: PubMed Central - PubMed

Affiliation: Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America.

ABSTRACT
Effects of conventional endurance (CE) exercise and essential amino acid (EAA) supplementation on protein turnover are well described. Protein turnover responses to weighted endurance exercise (i.e., load carriage, LC) and EAA may differ from CE, because the mechanical forces and contractile properties of LC and CE likely differ. This study examined muscle protein synthesis (MPS) and whole-body protein turnover in response to LC and CE, with and without EAA supplementation, using stable isotope amino acid tracer infusions. Forty adults (mean ± SD, 22 ± 4 y, 80 ± 10 kg, VO 2peak 4.0 ± 0.5 L ∙ min(-1)) were randomly assigned to perform 90 min, absolute intensity-matched (2.2 ± 0.1 VO2 L ∙ m(-1)) LC (performed on a treadmill wearing a vest equal to 30% of individual body mass, mean ± SD load carried 24 ± 3 kg) or CE (cycle ergometry performed at the same absolute VO2 as LC) exercise, during which EAA (10 g EAA, 3.6 g leucine) or control (CON, non-nutritive) drinks were consumed. Mixed-muscle and myofibrillar MPS were higher during exercise for LC than CE (mode main effect, P < 0.05), independent of dietary treatment. EAA enhanced mixed-muscle and sarcoplasmic MPS during exercise, regardless of mode (drink main effect, P < 0.05). Mixed-muscle and sarcoplasmic MPS were higher in recovery for LC than CE (mode main effect, P < 0.05). No other differences or interactions (mode x drink) were observed. However, EAA attenuated whole-body protein breakdown, increased amino acid oxidation, and enhanced net protein balance in recovery compared to CON, regardless of exercise mode (P < 0.05). These data show that, although whole-body protein turnover responses to absolute VO2-matched LC and CE are the same, LC elicited a greater muscle protein synthetic response than CE.

No MeSH data available.


Related in: MedlinePlus

Amino acids and insulin.Effects of load carriage, conventional endurance exercise, and essential amino acid supplementation on plasma essential amino acids (A), branched-chain amino acids (B), leucine (C), and insulin (D) during recovery. Data are mean ± SD, n = 10 per group. CE, conventional endurance exercise; LC, load carriage; CON, control; and EAA, essential amino acids. Drink x time (D x T) interaction for EAA, BCAA (branched-chain amino acids), leucine, and insulin. *Different from baseline for EAA groups, #from baseline for CON groups, and for EAA groups compared to †CON, D x T, P < 0.05.
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pone.0140863.g005: Amino acids and insulin.Effects of load carriage, conventional endurance exercise, and essential amino acid supplementation on plasma essential amino acids (A), branched-chain amino acids (B), leucine (C), and insulin (D) during recovery. Data are mean ± SD, n = 10 per group. CE, conventional endurance exercise; LC, load carriage; CON, control; and EAA, essential amino acids. Drink x time (D x T) interaction for EAA, BCAA (branched-chain amino acids), leucine, and insulin. *Different from baseline for EAA groups, #from baseline for CON groups, and for EAA groups compared to †CON, D x T, P < 0.05.

Mentions: EAA, BCAA, leucine, and insulin concentrations during recovery after LC and CE were higher for EAA than CON (drink x time, P < 0.05, Fig 5A–5D). More specifically, concentrations were increased above baseline 15 and 30 min post-exercise before returning (60 min) and dropping below baseline levels. Exercise mode did not augment plasma amino acids and insulin responses to exercise and EAA supplementation. Deltoid soreness immediately and 195 min post-exercise was higher for LC than CE (mode x time, P < 0.05, Table 4). Overall, quadriceps soreness was higher immediately post-exercise relative to195 min post-exercise and for CE compared to LC (mode and time main effects, P < 0.05). Gluteus soreness was higher for CE than LC immediately post-exercise and increased over time for CE, whereas there was no change over time in gluteus soreness for LC (mode x time, P < 0.05). Gastrocnemius/soleus soreness was higher immediately post-exercise relative to 195 min post-exercise but not different between modes (mode main effect P < 0.05). CK was similar between modes and increased 195 min post exercise compared to baseline (mode x time, P < 0.05). A small, but significant, increase in LDH occurred in response to both LC and CE, with no differences between modes (time main effect, P < 0.05). Overall, myoglobin was higher with LC than CE (mode main effect, P < 0.05). LDH and myoglobin tended to be higher 195 min post-exercise for LC than CE (mode x time, P = 0.51 and 0.55).


Human Muscle Protein Synthetic Responses during Weight-Bearing and Non-Weight-Bearing Exercise: A Comparative Study of Exercise Modes and Recovery Nutrition.

Pasiakos SM, McClung HL, Margolis LM, Murphy NE, Lin GG, Hydren JR, Young AJ - PLoS ONE (2015)

Amino acids and insulin.Effects of load carriage, conventional endurance exercise, and essential amino acid supplementation on plasma essential amino acids (A), branched-chain amino acids (B), leucine (C), and insulin (D) during recovery. Data are mean ± SD, n = 10 per group. CE, conventional endurance exercise; LC, load carriage; CON, control; and EAA, essential amino acids. Drink x time (D x T) interaction for EAA, BCAA (branched-chain amino acids), leucine, and insulin. *Different from baseline for EAA groups, #from baseline for CON groups, and for EAA groups compared to †CON, D x T, P < 0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608805&req=5

pone.0140863.g005: Amino acids and insulin.Effects of load carriage, conventional endurance exercise, and essential amino acid supplementation on plasma essential amino acids (A), branched-chain amino acids (B), leucine (C), and insulin (D) during recovery. Data are mean ± SD, n = 10 per group. CE, conventional endurance exercise; LC, load carriage; CON, control; and EAA, essential amino acids. Drink x time (D x T) interaction for EAA, BCAA (branched-chain amino acids), leucine, and insulin. *Different from baseline for EAA groups, #from baseline for CON groups, and for EAA groups compared to †CON, D x T, P < 0.05.
Mentions: EAA, BCAA, leucine, and insulin concentrations during recovery after LC and CE were higher for EAA than CON (drink x time, P < 0.05, Fig 5A–5D). More specifically, concentrations were increased above baseline 15 and 30 min post-exercise before returning (60 min) and dropping below baseline levels. Exercise mode did not augment plasma amino acids and insulin responses to exercise and EAA supplementation. Deltoid soreness immediately and 195 min post-exercise was higher for LC than CE (mode x time, P < 0.05, Table 4). Overall, quadriceps soreness was higher immediately post-exercise relative to195 min post-exercise and for CE compared to LC (mode and time main effects, P < 0.05). Gluteus soreness was higher for CE than LC immediately post-exercise and increased over time for CE, whereas there was no change over time in gluteus soreness for LC (mode x time, P < 0.05). Gastrocnemius/soleus soreness was higher immediately post-exercise relative to 195 min post-exercise but not different between modes (mode main effect P < 0.05). CK was similar between modes and increased 195 min post exercise compared to baseline (mode x time, P < 0.05). A small, but significant, increase in LDH occurred in response to both LC and CE, with no differences between modes (time main effect, P < 0.05). Overall, myoglobin was higher with LC than CE (mode main effect, P < 0.05). LDH and myoglobin tended to be higher 195 min post-exercise for LC than CE (mode x time, P = 0.51 and 0.55).

Bottom Line: Mixed-muscle and sarcoplasmic MPS were higher in recovery for LC than CE (mode main effect, P < 0.05).No other differences or interactions (mode x drink) were observed.These data show that, although whole-body protein turnover responses to absolute VO2-matched LC and CE are the same, LC elicited a greater muscle protein synthetic response than CE.

View Article: PubMed Central - PubMed

Affiliation: Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, United States of America.

ABSTRACT
Effects of conventional endurance (CE) exercise and essential amino acid (EAA) supplementation on protein turnover are well described. Protein turnover responses to weighted endurance exercise (i.e., load carriage, LC) and EAA may differ from CE, because the mechanical forces and contractile properties of LC and CE likely differ. This study examined muscle protein synthesis (MPS) and whole-body protein turnover in response to LC and CE, with and without EAA supplementation, using stable isotope amino acid tracer infusions. Forty adults (mean ± SD, 22 ± 4 y, 80 ± 10 kg, VO 2peak 4.0 ± 0.5 L ∙ min(-1)) were randomly assigned to perform 90 min, absolute intensity-matched (2.2 ± 0.1 VO2 L ∙ m(-1)) LC (performed on a treadmill wearing a vest equal to 30% of individual body mass, mean ± SD load carried 24 ± 3 kg) or CE (cycle ergometry performed at the same absolute VO2 as LC) exercise, during which EAA (10 g EAA, 3.6 g leucine) or control (CON, non-nutritive) drinks were consumed. Mixed-muscle and myofibrillar MPS were higher during exercise for LC than CE (mode main effect, P < 0.05), independent of dietary treatment. EAA enhanced mixed-muscle and sarcoplasmic MPS during exercise, regardless of mode (drink main effect, P < 0.05). Mixed-muscle and sarcoplasmic MPS were higher in recovery for LC than CE (mode main effect, P < 0.05). No other differences or interactions (mode x drink) were observed. However, EAA attenuated whole-body protein breakdown, increased amino acid oxidation, and enhanced net protein balance in recovery compared to CON, regardless of exercise mode (P < 0.05). These data show that, although whole-body protein turnover responses to absolute VO2-matched LC and CE are the same, LC elicited a greater muscle protein synthetic response than CE.

No MeSH data available.


Related in: MedlinePlus