The effect of different forms of exercise at maximal fat oxidation intensity on total fat oxidation

All metabolic processes that require energy are carried out using the energy produced by the breakdown of nutrients. The substrates used for energy production are mostly composed of carbohydrates and fats. The selection of the substrate to be used in meeting the energy needs is related to the amount of energy required. During low-intensity exercises, the amount of fat oxidation is higher compared to high-intensity exercises. Studies in the literature on the effects of exercise duration on fat oxidation are limited. In this study, the effects of different exercise protocols on fat oxidation in healthy and recreationally active individuals were examined. The study was conducted with 11 volunteer participants. Measurements were taken on four separate days, following a 12-hour fasting period. The measurements included anthropometric assessments, resting metabolic rate, maximal fat oxidation rate (FatMax) test, steady-state exercise (SSE), passive rest interval exercise (PRE), and active rest interval exercise (ARE). The results showed that the highest fat oxidation rate observed during the FatMax test was significantly higher than the average fat oxidation rates during SSE and PRE. However, no significant difference was found between the average fat oxidation rates observed in ARE and maximal fat oxidation in FatMax test. During the resting periods of the exercises, substrate oxidation amounts observed in ARE were found to be significantly higher. In passive rest exercises, the average heart rate was significantly lower compared to other exercise protocols. These findings have the potential to influence the planning of exercise programs.