People with HIV may have higher levels of fatigue as they age compared with their HIV-negative counterparts. This is according to initial data from a small study of 36 HIV-positive and 38 HIV-negative individuals age 50 and older that will investigate whether an exercise regimen affects fatigue. The HIV-positive participants had been taking antiretroviral treatment for at least two years, had a viral load lower than 200 and a CD4 count of 200 or higher. On subjective tests of fatigue, the participants in the HIV-positive group had lower scores than those in the HIV-negative group. On an objective test of fatigue, the HIV-positive individuals walked 400 meters (nearly a quarter mile) in an average of 255 seconds, compared with 229 seconds among the HIV-negative individuals. The researchers theorize that the greater apparent fatigue among the HIV-positive group may indicate that the virus serves as an independent risk factor for fatigue.