Introduction: The objective of the present work was to compare stress markers during known and different intensity running exercise in Forced Wheel by rats.
Methodology: After familiarization with forced running wheel, 45 male Wistar rats (8-week) were randomly assigned to seven groups including incremental-power test (n=6), constant-power test at 17.5 m/min (n=6), constant-power test at 16 m/min, constant-power test at 14.5 m/min, and constant-power test at 13 m/min. After determined visual lactate threshold by INCP group, the animals in other group was sacrificed immediately after termination constant power test in known intensity to evaluation stress markers (serum corticostrone, blood glucose, serum free fatty acids, and creatine kinase). One-way ANOVA used to identify differences between groups in the stress parameters (P≤0.05).
Results: The results indicated that the intensity equivalent to lactate threshold was determined by 15 m/min. Serum Corticostrone concentration in around of lactate threshold (14.5 m/min,16 m/min, and 17.5 m/min) significantly increased than control group. At all of the experimental group blood glucose concentrations were significantly higher than control group and 17.5 m/min higher than 10 m/min. With expectation of 10 m/min other groups serum fatty acids concentrations were significantly were increased compared to control group. Serum creatine kinase only in 17.5 m/min group showed significant increase as compared to the control group.
Discussion: We conclude that acute forced wheel running exercise in around of threshold lactate intensity (14.5, 16, and 17.5 m/min) increases physiologic demands in untrained Wistar rats. Due to the increase serum Corticostron, lactate accumulation and increased muscle damage in the intensity above lactate threshold, we suggest that researchers use initial speeds ≤14.5 m/min at aerobic training in physical training of untrained rat using FRW to achieve expected adaptations to exercise.