This study investigated how resistance training during fasting impacts strength, body composition, hormones, and sleep. Researchers compared two groups: one group trained fasted, the other after breaking their fast. Both saw similar body composition changes, but the fed group improved more in performance. Does fasting hold you back? Let’s dive in.
Overview
- What did they test? The researchers divided 37 physically active males into two training groups, both completing eight weeks of full-body resistance training, including four weeks during Ramadan fasting. During the fasting period, one group trained in a fasted state (n = 18), while the other trained several hours after breaking their fast (n = 19). Testing was conducted at four time points: two weeks before Ramadan, on the 15th and 29th days of fasting, and three weeks after Ramadan. Assessments included body composition, dietary intake, hormonal responses, maximal strength, and sleep quality.
- What did they find? The researchers found that squat and deadlift 1RM improved from before the fasting period to the 29th day of Ramadan only in the fed training group. Both groups experienced reductions in body mass, body fat percentage, and sleep quality during the fasting period. Cortisol levels increased acutely after training more in the fasted group at both fasting time points, while testosterone increased chronically during the fasting period in the fed group only. Notably, dietary intake was similar between the groups throughout the study.
- What does it mean for you? If you are using fasting to restrict your feeding window or as part of a religious practice, resistance training can still be performed. To maximise your progress during periods of intermittent fasting, especially your physical performance, training in a fed state is likely more beneficial.
What’s The Problem?
Intermittent fasting has gained popularity in recent years as a dietary approach, often used for weight management or explored for its potential health benefits 1. In this study, however, fasting was observed as part of Ramadan, a sacred month in Islam, which calls for additional context to fully understand its significance.
Ramadan is one of the holiest months for Muslims worldwide, marked by fasting from dawn to sunset as an act of devotion and self-discipline. During this time, Muslims abstain from food, drink, smoking, and sexual activity during daylight hours, with meals consumed only before dawn (suhoor) and after sunset (iftar). It is observed as part of a month of fasting, prayer and reflection 2. The widespread observance of Ramadan by millions of Muslims each year offers valuable opportunities for research, not only to support those observing Ramadan but also to inform broader applications for individuals practicing intermittent fasting.
Purpose
This study aimed to investigate the effects of resistance training performed in a fasted versus fed state on body composition, muscle strength, sleep quality, and hormonal responses in healthy males practicing fasting during the month of Ramadan.
Hypothesis
The authors hypothesized that resistance training could be performed safely in both fed and fasted states, but that training in a fed state would produce greater benefits for strength and maintaining typical hormonal responses.
What Did They Test and How?
Participants
Forty healthy and physically active males, with at least two years of resistance training experience, began the study, with an average age of 25.7 ± 5.6 years, weight of 85.1 ± 17.5 kg, and height of 175 ± 9 cm. While this data isn’t specific to the groups, initial testing showed similar starting points: the fasted group (n = 18) weighed 78.9 ± 3.7 kg with a body fat percentage of 16.6 ± 1.1%, and the fed group (n = 19) weighed 80.0 ± 3.5 kg with a body fat percentage of 16.3 ± 0.5%.
