Effects of 7°C environmental temperature during a 3-week training period

Cold environmental temperatures during exercise and recovery alter the acute response to cellular signaling and training adaptations. Approximately three weeks is required for cold temperature acclimation to occur. PURPOSE: To determine the impact of cold environmental temperature on training adaptations, fitness measurements, and aerobic performance. METHODS: Two groups of twelve untrained male subjects completed 1-hour of cycling in sixteen temperature acclimation sessions in either a 7 degrees C or 20 degrees C environmental temperature. Fitness assessments before and after acclimation occurred in standard room temperature. Muscle biopsies were taken from the vastus lateralis before training and after training to assess molecular markers related to mitochondrial development. RESULTS: PGC-1alpha mRNA was higher in 7 degrees C than 20 degrees C in response to acute exercise before training (p=0.012) but not after training (p=0.813). PGC-1alpha mRNA was lower after training (p 0.05). PGC-1alpha protein and mtDNA were not different before training, after training, or between temperatures (p>0.05). Cycling power increased during the daily training (p<0.001) but was not different between temperatures (p=0.169). VO2peak increased with training (p<0.001) but was not different between temperature groups (p=0.460). CONCLUSION: These data indicate that a three-week period of acclimation/training in cold environmental temperatures alters PGC-1alpha gene expression acutely but this difference is not manifested in a greater increase in VO2peakand is dissipated as acclimation takes place.