Background and Purpose: The pre-pubertal period is one of the critical stages of brain development and motor pattern formation. However, the long-lasting effects of different types of exercise training during this period on locomotor performance in adulthood have been less investigated. This study aimed to determine the effect of three weeks of voluntary, forced, and environmental enrichment exercise during the pre-pubertal period on locomotor performance in the open field test in adult male rats.

Materials and Methods: Twenty-four male Wistar rats (28 days old) were randomly divided into four equal groups: control, voluntary exercise, forced exercise, and environmental enrichment. The voluntary group had free 24-hour access to a running wheel for three weeks (6 days/week). The forced group trained based on the mean distance and speed of the voluntary group. The enrichment group had access to an enriched cage for 4 hours/day, 6 days/week. Locomotor performance was assessed using the open field test on days 50, 65, 80, and 95. Body weight and food consumption were recorded. Data were analyzed using one-way ANOVA and Tukey's post hoc test (P < 0.05).

Results: At all four time points, there were significant differences in locomotor performance between groups (P < 0.05). On day 50, the enrichment group (5883±440 cm) and voluntary group (5269±342 cm) showed the highest, and the control group (2751±904 cm) the lowest distance traveled. The enrichment group performed better than both forced and voluntary groups (P < 0.05). On day 95, the enrichment group (5726±275 cm) still maintained the highest performance. No significant differences were observed between voluntary and forced groups at any time point. Regarding food consumption, during the detraining period (50-95 days), the control group consumed significantly more food than all three experimental groups (P < 0.01), while during the training period (28-50 days), only the difference between control and forced groups was significant (P = 0.036). Regarding body weight, on days 80 and 95, the control group had significantly higher body weight than all three experimental groups (P = 0.012). Additionally, on day 95, the enrichment group had significantly higher body weight than the forced group (P = 0.015).

Conclusion: Three weeks of training during the pre-pubertal period, especially environmental enrichment, has long-lasting effects on improving locomotor performance until early adulthood. With equalization of training volume and intensity, no significant difference was observed between voluntary and forced exercise on locomotor performance. Environmental enrichment is the most effective intervention for long-term improvement of locomotor performance. Exercise interventions were associated with reduced body weight and food consumption during follow-up