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.
AGE. Although the HIV risk factors are the same for everyone, some groups merit special consideration because of their age. For example, in the U.S. new HIV infections are increasing among young men who have sex with men, especially young, black men who have sex with men (ages 13-24), despite remaining steady overall.ho is at Risk for HIV? HIV can be transmitted through certain bodily fluids: blood, semen (cum), pre-seminal fluid (pre-cum), rectal fluids, vaginal fluids, and breast milk.