King Grub
2013-02-27, 16:35
PURPOSE:
The purpose of this investigation was to determine the impact of post-exercise environmental cold exposure on muscle glycogen, PGC-1α, and downstream transcription factors.
METHODS:
Eight males cycled for 1 h and recovered in either 7° C (cold) or 20° C (room temp) environment for 4 h. Muscle biopsies were obtained pre, post, and 4 h post exercise for the analysis of muscle glycogen and mRNA. During recovery participants consumed 1.8 g·kg(-1) of body weight of an oral dextrose solution immediately following the post biopsy and 2 h into recovery. Blood samples were obtained post exercise and at 30, 60, 120, 150, 180, and 240 min post exercise for the analysis of serum glucose and insulin AUC.
RESULTS:
Oxygen uptake was lower during room temp than during cold recovery (0.40 ± 0.05 L·min(-1) vs. 0.80 ± 0.12 L·min(-1); p<0.01). There was no effect of temperature on muscle glycogen recovery or glucose AUC. However, insulin AUC was greater during the room temp trial compared to the cold trial (5139 ± 1412 vs. 4318 ± 1272, respectively; p=0.025). PGC-1α gene expression was higher (p=0.029), but ERRα and NRF2 were lower (p=0.019 and p=0.046, respectively) after recovery in the cold. There were no differences in NRF1 (p=.173) or TFAM (p=0.694).
CONCLUSIONS:
This investigation shows no effect of a cold recovery environment on glycogen re-synthesis but does demonstrate reduced ERRα and NRF2 mRNA despite elevations in PGC-1α mRNA when recovery post-exercise takes place in a cold environment.
Cryobiology. 2013 Feb 21. pii: S0011-2240(13)00030-8. Effects of post-exercise recovery in a cold environment on muscle glycogen, PGC-1α, and downstream transcription factors.
The purpose of this investigation was to determine the impact of post-exercise environmental cold exposure on muscle glycogen, PGC-1α, and downstream transcription factors.
METHODS:
Eight males cycled for 1 h and recovered in either 7° C (cold) or 20° C (room temp) environment for 4 h. Muscle biopsies were obtained pre, post, and 4 h post exercise for the analysis of muscle glycogen and mRNA. During recovery participants consumed 1.8 g·kg(-1) of body weight of an oral dextrose solution immediately following the post biopsy and 2 h into recovery. Blood samples were obtained post exercise and at 30, 60, 120, 150, 180, and 240 min post exercise for the analysis of serum glucose and insulin AUC.
RESULTS:
Oxygen uptake was lower during room temp than during cold recovery (0.40 ± 0.05 L·min(-1) vs. 0.80 ± 0.12 L·min(-1); p<0.01). There was no effect of temperature on muscle glycogen recovery or glucose AUC. However, insulin AUC was greater during the room temp trial compared to the cold trial (5139 ± 1412 vs. 4318 ± 1272, respectively; p=0.025). PGC-1α gene expression was higher (p=0.029), but ERRα and NRF2 were lower (p=0.019 and p=0.046, respectively) after recovery in the cold. There were no differences in NRF1 (p=.173) or TFAM (p=0.694).
CONCLUSIONS:
This investigation shows no effect of a cold recovery environment on glycogen re-synthesis but does demonstrate reduced ERRα and NRF2 mRNA despite elevations in PGC-1α mRNA when recovery post-exercise takes place in a cold environment.
Cryobiology. 2013 Feb 21. pii: S0011-2240(13)00030-8. Effects of post-exercise recovery in a cold environment on muscle glycogen, PGC-1α, and downstream transcription factors.