The Effect of Ramadan Fasting on Maximal Effort Levels, Time to Exhaustion, Recovery Time, and Rating of Perceived Exertion in a Sample of Physically Active Healthy Adults

Abstract

This study aimed to investigate the effect of Ramadan fasting on maximal effort levels, time to exhaustion, recovery time, and the rating of perceived exertion in a sample of physically active, healthy adults. To achieve this, 22 physically active adult males participated in the study, with a mean age of (20.08 ± 1.62) years, height of (175.83 ± 6.93) cm, and weight of (72.67 ± 7.55) kg.

Participants performed a graded maximal exercise test, followed by the application of the study protocol at an intensity of 75% of maximal resistance on a stationary cycle ergometer until voluntary exhaustion. Heart rate was recorded every minute throughout the experiment. The rating of perceived exertion was also measured every minute for the legs, chest, and the body as a whole. Recovery time was assessed by monitoring heart rate after the completion of both tests until it returned to resting levels.

The results of the paired sample t-test using mixed linear models showed no statistically significant differences in maximal effort levels (power output in watts during the graded maximal exercise test) or in the rate of increase in the rating of perceived exertion for the legs during Ramadan fasting compared to after Ramadan.

However, the results revealed statistically significant differences (P < 0.001) in favor of the non-fasting condition (after Ramadan) in heart rate and recovery time. In the constant relative intensity test (75% of maximal resistance) until exhaustion, the results also showed statistically significant differences (P < 0.001) in the rate of increase in the rating of perceived exertion for the legs, chest, and the whole body over the duration of exercise, with faster increases observed during Ramadan fasting.

Additionally, significant differences were found in heart rate and recovery time, both of which were lower in the non-fasting condition. Significant differences were also observed in time to exhaustion, which was longer in the non-fasting condition.

The study concluded that fasting is closely associated with increased physiological and perceptual load during prolonged physical exertion. The researcher recommended scheduling training sessions after breaking the fast (Iftar) to allow for adequate replenishment of fluids and electrolytes.