Tuesday, February 06, 2007

Coffee, Coffee, Coffee

I love coffee! I love the way it tastes, smells and the buzz it gives me. I go in phases though. Right now I drink more than I used to. I will probably let myself drink this amount for another 4 weeks and then before my race I will make myself cut back. This way during my race I will have a better effect from using caffeine on my performance. Your body gets used to a certain amount of caffeine and eventually that amount of caffeine just gets you to "normal." You know the feeling- you drag yourself out of bed and over to the coffee pot and it isn't until you've had your first sip that your eyes open and you start to wake up. You don't want caffeine to just get you to "normal" on race day, you want to experience the ergogenic benefit...speaking of- what is the ergogenic benefit of caffeine?

For most of us, caffeine provides a stimulus for concentration or waking up. In an athletic event, however, it can be used to prolong endurance exercise and enhance power production.

Here's the research-
Initial studies(Med Sci Sports exerc 10,155) examining the effect of caffeine supplementation on endurance performance reported a 21-minute improvement in time to exhaustion while cycling at 80% of VO2max. Similarly, research done(J Sports Med Phys Fitness, 31, 425)on elite distance runners who consumed 10mg of caffeine per kg of body mass immediately before a treadmill run to exhaustion significantly improved their performance by 1.9% compared with controls. In another study(Can J Appl Physiol, 20, 168), competent distance swimmers consumed caffeine (6mg per kg of body mass) 2.5 hours before swimming 1500m and found that their split times improved significantly for each 500m of the swim, while average swim times were 1.9% faster than when carried out without the aid of caffeine.

A study(Int J Sports Med, 16, 225)on endurance cyclists looked at the effect on time to exhaustion of pre-exercise administration of each of the following:

* 5mg caffeine per kg body mass;
* 9mg/kg caffeine;
* 13mg/kg caffeine;
* placebo.

In a test carried out at 80% of their maximal power output, all the caffeine-supplemented cyclists showed a 24% improvement in time to exhaustion. However, no greater benefits were apparent with doses of caffeine higher than 5mg per kg of body mass.

What does all of this research mean for you?

1. Using small amounts of caffeine (as little as contained in one mug of coffee) have been shown to have a favourable impact on factors like decision-making and reaction time, while larger amounts (equal to 2-3mg per kg of body mass) have been shown to enhance exercise performance, particularly endurance.

2. Take a caffeine pill instead of coffee. Research has shown that the potential performance enhancing effects of caffeine taken in the form of coffee are lower than when taken as a capsule with water.

3. Consume additional fluid to offset the diuretic effects of caffeine when it is taken prior to exercise. Caffeine can act as a diuretic, which could lead to an unnecessary pre-exercise loss of fluid, with negative knock-on effects on thermal balance and exercise performance, particularly in hot environments. However, this diuretic effect is reduced when caffeine is consumed during exercise, which helps to explain why relying on gu's with added caffeine while racing will work.

4. Don't take too much! Dosages higher than 5mg per kg of body mass do not appear to elicit any greater performance effects; furthermore, they tend to raise the risk of unwanted side effects. Do not use more than 5mg/kg of body mass.

5. Take caffeine within 3 hours of your event starting and continue taking it every 3 hours. Caffeine is absorbed rapidly, with peak plasma concentration reached in around one hour. It also clears from the body fairly rapidly, taking about 3-6 hours for blood caffeine concentrations to decrease by one half.

6. Practice! As with any intervention, individual responses will vary, and athletes should rehearse their caffeine dosage strategy thoroughly before putting it to the test in a key event. Athletes who normally avoid caffeine may experience adverse effects. Many of these side effects are well known and include anxiety, gastrointestinal disturbances, restlessness, insomnia, tremors and heart arrhythmias. The scientific literature suggests that the risk of such side effects is increased if caffeine is taken in doses higher than 9mg per kg of body mass. I have a rule- "Nothing New on Race Day." Practice using whatever you are going to use on race day on a workout day. Don't wait until race day to try out a caffeine pill, you never know how you will feel from it.

7. Be aware that beneficial effects do not occur consistently in habitual caffeine users, because of a level of ‘caffeine tolerance’. If you are at the point where coffee gets you to "normal" you may not see an improvement in your performance with caffeine. One way round this may be for caffeine users to eliminate all caffeinated foods and drinks for a period of 4-6 days prior to the event in order to optimise its benefits.