Exercise Training in the Fasted State During the Month of Ramadan: Acutely Ergolytic but Possibly Chronically...

Daytime acute exercise in the Ramadan-fasted state (without consuming food nor fluids before and during exercise) can lead to exacerbated physiological responses and poorer performance in fasting individuals. Consequently, chronic training adaptations under these conditions are often expected to be suboptimal compared with the same training sessions performed in the fed state.

This narrative review (supported by a systematic search for Ramadan training-adaptation studies and methodological quality assessment), in contrast, examines whether chronic training in the Ramadan-fasted state may preserve, impair, or in selected contexts possibly augment training-induced adaptations. This premise is informed by adjacent evidence indicating that training in the fasted state has been associated with enhanced training-induced adaptations via greater activation of mitochondrial biogenesis and resulting in higher levels of metabolic enzymes for glycolysis, oxidative phosphorylation, and overall metabolic capacity (in non-Ramadan fasted or carbohydrate-restricted models). Similarly, evidence from adjacent non-Ramadan models suggests that training in a permissive (mild) dehydrated state vis-à-vis Ramadan fasting may promote positive adaptations via enhanced plasma volume expansion and greater thermoregulatory-physiological response during exercise. The systematic search identified 10 eligible studies, of which six were rated as strong methodological quality and four as moderate quality. Based on these studies, the proposed efficacy of Ramadan-fasted training-induced adaptations remains speculative, although Ramadan-specific studies have reported either improved or preserved training-induced performance outcomes within Ramadan-fasted groups. Compared to non-fasted and fed-state training, there appears to be some support for greater aerobic adaptation in Ramadan-fasted training specifically for middle distance running and running capacity assessed via time-to-exhaustion.

In summary, we postulate that training sessions performed in the Ramadan-fasted state, while acutely ergolytic, may not necessarily blunt chronic adaptation when training load, recovery opportunity, and post-exercise nutrition and hydration are well managed. However, the available evidence is limited, heterogeneous, and methodologically constrained. Therefore, Ramadan-fasted training should not be considered generally superior to fed-state training; rather, its potential additional adaptive stimulus remains plausible mainly for selected aerobic outcomes and requires confirmation through well-controlled Ramadan-specific studies.