Most studies related to the effect of exercise training on the immune system of HIV infected individuals involve primary or only aerobic type exercises. Improvement on cardiorespiratory fitness and mental health, with little or no influence on variables related to the immune system (CD4, CD4/8, number of virus RNA copies) have been reported. Such studies usually presented small series with high dropout rates, in which individuals with distinct levels of immune involvement (different stages of infection) were submitted to the same exercise programs and with results being evaluated together. The purpose of this review was to identify the level of scientific evidence and the degree of recommendation for aerobic, strength, and flexibility exercises adopted by major longitudinal studies investigating physical, psychological, and immune influences of exercise training on HIV infected individuals. Considering the foregoing, basic lines of exercise prescription and future research were also established. The authors verified that none of the studies reviewed presented level I of evidence, which implies a relevant risk of error in relation to design inferences. Individuals with more advanced stages of infection often represented a minority of the subjects, thus minimizing their influence on the results. In addition, the most consistent studies in terms of method (level II of evidence) used a short period for intervention (6 to 12 weeks), thus making it impossible to identify negative trends, particularly with respect to more intense exercise. Therefore a safe exercise prescription should take into account age, gender, physical activity history, physical fitness, organic involvement, and the goals of the infected subject. Similar concerns apply to future studies, i.e., the investigation of immune effects of different types of exercise also in infected children and women is of vital importance.
AIDS; Exercise training; HIV infection; Aerobic exercise; Muscle strength; Flexibility; Mental health
