EXERCISE TRAINING AND HIV

BY: Suzann Knoetzen

Patients with HIV infection, but without acquired immunodeficiency syndrome (AIDS) or pulmonary disease, have a reduced workload, lower anaerobic threshold, and poorer aerobic capacity than do age-matched controls (Roubenoff, Skolnik, Shevitz, Snydman, Wang, Melanson & Gorbach, 1999).  During the course of the illness the HIV positive patient may experience muscle wasting and weakness, fatigue and depression (Mustafa, Sy, Macera, Thompson, Jackson, Selassie & Dean, 1999).  Exercise training is an appealing addition to antiretroviral therapy in rehabilitating the exercise capacity and functional status of patients with HIV infection.  Both aerobic and resistance training may be important adjuncts to the antiretroviral treatment of HIV infection (Roubenoff et al., 1999).  The aerobic exercise prescription for HIV infected individuals has typically involved the use of treadmill walking and stationary cycling.  These modes of exercise have typically been performed 3 days per week for a total duration of 10-24 weeks at intensities ranging between 50% - 80% VO2max or 60% - 85% maximum heart rate (Dudgeon, Phillips, Bopp & Hand, 2004). Several studies reviewed by Dudgeon et al. (2004) revealed that resistance training programs for HIV infected persons generally consisted of 3 sessions per week with 3 sets of 8 repetitions on each exercise.  Furthermore, it was found that when aerobic and resistance training were combined the programs usually lasted 12-16 weeks and included 20 minutes aerobic exercise followed by 35 to 40 minutes of resistance training.     

The success of exercise in effectively reducing the risk of cardiovascular and other chronic diseases as well as improving mental health is well documented.  Several studies involving HIV infected individuals in a structured program of moderate physical activity for periods ranging from 8-15 weeks led to enhanced immunity and lower risk of some infections.  Some randomized control studies suggested beneficial effects of exercise on immunologic and psychological parameters in HIV positive individuals.  Furthermore, several reports have been made concerning improvement in muscle strength and flexibility, cardiopulmonary function, decreased anxiety, depression and anger, and increase in the CD4 cell counts following exercise training (Mustafa et al., 1999).  

The goals of regular aerobic exercise training in HIV positive patients include:

·        Improved aerobic capacity and functional status;

·        Improved immune function;

·        Maintenance of or improvements in lean body mass/weight;

·        Improved mood (reduced depressive symptoms); and

·        Improvement in quality of life (Stringer, 1999).

Short term bouts of exercise do enhance the number of CD4 cells, neutrophils and cells mediating natural immunity in HIV-seropositive patients.  There is as yet no convincing data that longer term exercise is associated with improved resting levels of CD4 cells in HIV patients.  Exercise training does not however, appear to adversely affect HIV positive patients (Nieman et al., 1999).  Several studies with symptomatic and asymptomatic HIV positive patients indicate that aerobic exercise may produce a health benefit by direct improvement of cardiopulmonary, immune system function and quality of life (Perna, LaPerriere, Klimas, Ironson, Perry, Pavone, Goldstein, Majors, Makemson, Talutto, Schneiderman, Fletcher, Meijer & Koppes, 1999).