#200 mg of caffeine half life trial

#200 mg of caffeine half life trial

In an 8K time trial involving well-trained male runners, a 24-second, or 1.8%, improvement was observed with 3mg/kg caffeine ingested sixty minutes before the event (Spriet, 2014). Some researchers found that 150-200mg of caffeine improved 1500m performance by 4.2s in well-trained males, whereas another study involving a longer distance event (3 x 18km in 8 days) showed no performance effect of low-dose (90mg or ~1.3mg/kg) (Spriet, 2014). In running performance, the evidence is a bit less consistent. Caffeine intake pre-workout showed 4.2% and 2.9% improvement in cycling performance when 3 and 6mg/kg were consumed, respectively, indicating a decrease in dose-response efficacy similar to the first two studies mentioned (Spriet, 2014).

The cyclists who took the 3 and 6mg/kg doses showed a 22% increase in time trial performance while the high-dose group demonstrated only an 11% non-significant increase (Spriet, 2014).Īnother study, where well-trained cyclists ingested low-dose caffeine late in an endurance race, showed that both 1.5 and 3mg/kg were ergogenic when ingested late in an exhaustive ride (Spriet, 2014). Cyclists ingested 3, 6, and 9mg/kg of caffeine sixty minutes before the time trial (Spriet, 2014). The first dose-response study, performed in 1995, involved a cycling time trial performance test. Higher doses often result in gastrointestinal upset, dizziness, nervousness, insomnia, confusion, tachycardia (rapid heart rate), and the inability to focus (Spriet, 2014). Low doses of caffeine, 3mg/kg body weight or less, improve vigilance, alertness, mood, and cognitive abilities without negative side effects (Spriet, 2014). With a half-life of three to five hours, caffeine’s effects can last for the better part of a day. Peak levels in the blood occur between forty and eighty minutes, making it ideal for immediate training benefit (Spriet, 2014). Caffeine is rapidly absorbed by the body within five to fifteen minutes of ingestion. Researchers continue to study caffeine, which is allowed by the NCAA and US Olympic Committee, to determine its enhancement effects on athletic performance in training and competition.

Given the inconclusive evidence surrounding the use of caffeine as a performance-enhancing supplement and the significant metabolic consequences on glucose disposal in a sedentary state, athletes should use caution and consume caffeine in moderation.