The purpose of this study is to investigate the effects of N-acetyl Cystein (NAC) supplementation on redox status, physiological and biochemical parameters in G6PD deficient individuals after acute exercise.

In a randomized double-blind, crossover design, 12 adult volunteers with G6PD deficiency of both sexes will be supplemented with either 10 mg/kg of NAC (experimental condition - EC) or placebo (control condition - CC) every day for 4 weeks. Before intervention, all participants will be informed about the study protocol, fill a medical history questionnaire and sign an informed consent form. Moreover, measurements of anthropometric characteristics and physiological parameters, as well as a VO2max test will be performed.

Participants will perform 4 trials of exercise (70% VO2max for 45min and 90% till exhaustion) before and after each condition. Blood samples will be collected before, immediately after and 1 hour after exercise. Moreover, measurements of anthropometric characteristics and physiological parameters will be performed before and after each condition. There will be a washout period of at 4 weeks between conditions.

Inclusion Criteria:

• G6PD deficiency

Exclusion Criteria:

• Any uncontrolled health condition for which exercise is contraindicated
• Current use of dietary supplements or drugs
• Pregnant, pregnancy intention or breast feeding