By Angela Bentley
Walking through supplement aisles, it is easy to get confused about what works and what doesn’t. There are many sports supplements making all sorts of unsubstantiated claims and in reality very few are proven to be effective. I must also remind you that the market is unlegislated making the likelihood of contamination and the presence illegal substances high.
Caffeine, the humble stimulant found in coffee, was previously on the banned substance list, however with a wealth of research to show that caffeine enhances both endurance and high intensity performance in trained athletes, 12 μg of caffeine per ml of urine is now allowable.
Caffeine is one of the few sports supplements which has been extensively researched and is recognised to be generally effective and safe as an ergogenic aid. I think that anybody that has had a strong cup of coffee before a workout will understand why!
How does it work?
By stimulating the nervous system caffeine helps to make free fatty acids available from fat cells (sounds good to me!). These free fatty acids are then available to the body as a source of energy to fuel your exercise.
Caffeine also causes an increase in the “fight or flight” hormone, adrenaline. Adrenaline increases heart-rate, breathing-rate and energy production, preparing the body for an intense workout.
Who and for what?
Caffeine has been shown to improve exercise performance by 11-12%
- Caffeine has been shown to enhance ones maximum endurance performance, which can be extremely useful in improving time trial speeds
- In conditioned athletes caffeine has been shown to assist in prolonged high intensity exercise such as rugby, soccer, rowing, hockey etc.
- Use in strength and power training is still controversial with mixed findings, but studies show that it may help trained athletes
- Caffeine enhances vigilance and alertness, which can assist athletes in exhaustive exercises which require alertness
- When combined with carbohydrates, caffeine can enhance glycogen re-synthesis during recovery from exercise.
How much and when?
It is generally recommended that caffeine in a low to moderate dose (3-6mg/kg) be taken 60 minutes before exercise to allow for optimal absorption. Intake above 9mg/kg is not shown to have any additional advantage. Interestingly, consumption as little as 15-30 minutes before has still produced enhanced performance.
It is important to bear in mind that caffeine can negatively influence your sleep, which could inhibit proper recovery. Therefore it is advisable to avoid consuming caffeine after mid-afternoon if you are caffeine sensitive
What is the best form of caffeine?
Caffeine is caffeine. To get to 3mg per kg of body weight you would need to consume about 2 cups (250ml size) of percolated coffee. If you aren’t a coffee person there is always the option of taking a pill.
Will caffeine cause dehydration?
Studies have shown that caffeine induced diuresis does not take place during exercise. There has been no change in sweat rate, fluid loss or any negative changes in fluid balance caused by caffeine. This is true even in extreme heat. Sufficient fluid intake is still very important for recovery.