Cycling is a recreation, a sport and a means of transport across land. It involves riding bicycles, unicycles, tricycles, quadricycles and other human powered vehicles (HPVs). As a sport it is governed internationally by the Union Cycliste Internationale in Switzerland (for upright bicycles) and by the International Human Powered Vehicle Association (for other HPVs).
Term used to describe strategies for boosting nutrient levels without adversely effecting the body's ability to synthesize key substances. For example, a bodybuilder might supplement with an amino acid at high intake levels for a few days (the "loading" phase), then take a lower dose for a longer period of time ("maintenance" phase), then stop taking the specific supplement altogether for a period of time ("cycling") to restore the body's ability to produce the amino acid naturally.
Discharge lamps may sometimes cycle on and off towards the end of their life. It is an undesirable situation which may damage control gear, and most lamp and gear circuits protect against it. It may be due to incorrect lamps, improper voltage being supplied, or high ambient temperature around the luminaire.