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).
While anyone who has sex can get an STD, sexually active gay, bisexual and other men who have sex with men (MSM) are at greater risk. In addition to having higher rates of syphilis, more than half of all new HIV infections occur among MSM.Many factors contribute to the higher rates of STDs among MSM:he only way to know your STD status is to get tested (you can search for a clinic here). Having an STD such as herpes makes it easier to get HIV, so itâs important to get tested to protect your health and the health of your partner. CDC recommends sexually active gay, bisexual and other MSM test for: