AN EARLY STARTED OVERLOAD SWIMMING PROTOCOL ATTENUATED OBESITY BUT ACTED AS ANXIOGENIC IN WESTERN DIET-FED FEMALE RATS

Aim: To evaluate the influence of an early overload swimming training (OST) on the development of obesity and anxiety-like behavior in female rats fed a cafeteria diet (Caf). Main methods: Sixty-six Female Wistar rats (21 days old, 11/group) were grouped as: Chow-fed sedentary (Ch-S), Chow-fed exercised once per week (Ch-E1), chow-fed exercised 5 days/week (Ch-E5), Caf-fed sedentary (Caf-S), Caf-fed exercised once per week (Caf-E1), and Caf-fed exercised 5 days/week (Caf-E5). OST was initiated the next day (45 min/ 5% body weight overload). The Caf diet started at 31 days of life, with the addition of hypercaloric foods to the commercial rat chow and water. Both Caf and OST continued for 60 days. Key findings: Caf-S rats displayed increased calorie intake, body weight, abdominal fat deposits, triglyceridemia, and abdominal circumference. This increase in obesity markers was prevented by OST, with being E5 more efficient than E1. Caf did not alter behavior, but Caf-E1 and Caf-E5 spent less time in the open arms of the elevated plus maze than the Caf-S group, indicating that the association of Caf + exercise was anxiogenic. As there were no alterations in the number of entrances in the enclosed arm and no differences in mobility in the open field test, this cannot be attributed to a motor effect. Significance: OST was effective in reducing obesity markers that were increased by the cafeteria diet but was also anxiogenic. OST in females may induce chronic stress that should be considered during the interpretation of its anti-obesity effect.