Stimulants

Stimulants are a group of drugs that increase activity in the body, sometimes called "uppers". They speed up the messages travelling between the brain and the body (partly by increasing dopamine levels), producing short-term effects such as heightened energy, alertness, confidence and reduced fatigue; they may be snorted, swallowed, smoked or injected. While users may feel good in the short term, long-term abuse has serious consequences.

How they work physiologically

Stimulants act mainly on the central nervous system by increasing the levels of catecholamines — dopamine and norepinephrine — at the junctions between nerve cells. This speeds up reaction time, raises heart rate and blood pressure, and dampens the brain's normal perception of fatigue, which is exactly why an athlete on stimulants can push through a level of tiredness that would otherwise force them to slow down.

Why athletes misuse them

The appeal is directly tied to the physiological effect: endurance and team-sport athletes use stimulants to delay the feeling of fatigue late in a race or match, while athletes in explosive and combat sports use them for the extra alertness, confidence and controlled aggression. Because the effect is immediate rather than something built up over weeks of use, stimulants are particularly associated with in-competition misuse rather than long-term training-phase misuse.

Detection and WADA status …