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.
What Increases Your Risk. Most people get HIV by having unprotected sex with someone who has HIV. Another common way of getting the virus is by sharing needles with someone who is infected with HIV when injecting drugs. You have an increased risk of becoming infected with HIV through sexual contact if you: 1  Have unprotected sex (do not use condoms). 2  Have multiple sex partners. 3  Are a man who has sex with other men.  Have high-risk partner(s) (partner has multiple sex partners, is a man who has sex with other men, or injects drugs).
In other words, sex with condoms isn't totally safe sex, but it is less risky sex. HIV infection is, by far, the most deadly STD, and considerably more scientific evidence exists regarding condom effectiveness for prevention of HIV infection than for other STDs. condom is especially important when an uninfected pregnant woman has sex, because it can also help protect her and her unborn child from a sexually transmitted disease. Condoms are not 100% safe, but if used properly, will reduce the risk of sexually transmitted diseases, including AIDS.