Comparison of Cumulative Effects of Four Days of Alternate or Continuous Training on Expression of Selected Mitochondrial Genes in Rat Skeletal Muscle

Introduction Adaptations to training include the accumulation of specific proteins. The ideal stimulus that alters gene transcriptive response that initiates changes in protein concentration is important for adaptations. Methods Fifty-four male Sprague-Dawley rats were randomly divided into 9 experimental groups, with six rats in each group. The groups consisted of: control (group 1); one day of training (2); continuous training groups who trained for a further two to four days followed by three days recovery (3,4,5,6); alternate-day training consisting of a further two to four sessions (7,8,9) finishing on the 7th day. On each training day, the animals ran on a motor driven treadmill at a slope of 10° and a speed of 19.3 m/min (∼76%VO2max) for 90 minutes. Gastrocnemius muscle specimens were obtained from the respective groups 1 hour after training ceased. Real-time PCR was performed to determine the changes (in fold) in mRNA of PGC1α, COXIV, CaMKIV, NRF1, AMPKα1 and α2, and mtTFA. One-way ANOVA was used in comparisons of the mean values between groups. Results The results showed that mRNA expression was significantly different between the training groups for AMPkα1 after the 3rd training session, PGC1α after the 4th training session, with CaMKIV significantly different following three days of recovery. COXIV and mtTFA were not significantly different at any point. Conclusions Training design has differing effects on expression of the selected genes. This data has provided insight into the importance of training design and recovery intervals which warrants a need for further research. Ethical Animal Research The study was approved by the Southern Cross University Animal Care and Ethics Committee. Sources of funding: None declared. Competing interests: none.