1 Isotonic -a muscle fiber contraction in which force production is unchanged when the muscle contracts causing movement of an external load.  Isokinetic -a muscle fiber contraction in which force production of the contraction is sufficient to overcome the external load.
HIV/AIDS. HIV Risk Behaviors. The risk of getting HIV varies widely depending on the type of exposure or behavior (such as sharing needles or having sex without a condom). Some exposures to HIV carry a much higher risk of transmission than other exposures.
The risk of anal cancer is about 17 times higher in sexually active gay and bisexual men than in men who have sex only with women. Men who have HIV (human immunodeficiency virus) are also at higher risk of getting this cancer. Other types of HPV virus rarely cause cancer in men, but they do cause genital warts.