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.
1 Meanwhile, women have a higher risk of getting HIV from men. 2  Because HIV is in the man's semen, which can stay in the woman's vagina for days, her exposure time is longer after sex. 3  Also, the vagina provides a much larger area than the penis does through which HIV can enter the woman's body.