Women should never train in a fasted state, as doing so risks disrupting their stress hormones and blocking recovery. Unlike men, who tolerate low energy levels (a threshold of 15 kcal/kg of lean mass), women require a minimum energy intake (such as a protein latte) because their metabolic threshold is 35 kcal/kg.

noli's read

Clinical research conducted by physiologist Dr. Anne Loucks confirms that the threshold for low energy availability triggering hormonal disturbances in women is situated around 30 to 35 kcal per kg of lean mass per day. Conversely, randomized clinical trials conducted on male athletes suggest that men are more resilient and tolerate lower restrictions, sometimes down to 15 kcal/kg, before showing signs of fatigue or decreases in testosterone. Furthermore, the temporary elevation of cortisol (a stress hormone) during fasted exercise is well documented in physiological research. However, asserting that fasted exercise systematically blocks recovery or is harmful for all women is an exaggeration. A randomized clinical trial comparing fasted and fed cardio in women over four weeks revealed no significant difference in their long-term weight or body composition. Finally, the 35 kcal/kg threshold mentioned by specialist Dr. Stacy Sims refers to the total daily nutritional intake, not a strict requirement for a snack immediately before exercise. Thus, while vigilance regarding chronic energy deficiency is essential to preserve female well-being, training in a fasted state remains entirely possible for moderate sessions depending on individual comfort.

the sources

1. 1Hackett D, Hagstrom AD 2017
2. 2Vieira AF, Costa RR, Macedo RCO, Coconcelli L, Kruel LFM 2016