The Effect of Endurance Training, Detraining and Shock Training on Monocarboxylate Transporters in the Gastrocnemius Muscle and Endurance Performance of Male Rats

Aerobic training can have an important role in the delay of metabolic fatigue occurrence by increasing lactate transporters. However, changes in monocarboxylate transporters (MCTs) during the detraining period and the effect of, so-called, shock training on the maintenance of training adaptations during the detraining period have remained unknown.The purpose of this study was to investigate the effect of endurance training, detraining and shock training on the endurance performance and protein levels of monocarboxylate transporters (MCT1 and MCT4). The training program consisted of running on the treadmill for 12 weeks (5 days a week). The detraining/shock training protocol (one session per week, for 40 minutes at a speed of 20-30 m/min) was applied from 10th to 12th week. Levels of MCT1 and MCT4 were measured by the ELISA method. The levels of MCT1 in the endurance training group were higher than the control group (P= 0.001). However, there were no significant differences in the level of MCT1 among detraining, endurance training (P=1.000) and shock training (P=0.9981) groups. Endurance training, detraining and shock training groups didn’t change MCT4 levels (P=0.148). Detraining significantly decreased endurance performance compared with the endurance training group (P=0.001). Despite the decreased performance of the shock training group compared to the endurance training group (P=0.0001), shock training prevents detraining induced performance loss (p=0.006). Endurance training increases the MCT1 level of the gastrocnemius muscle. This increase is not influenced by detraining or shock training. However, it seems that shock training can ameliorate the loss of endurance performance caused by detraining.