caffeine

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here are a couple of articles (sites) that may help explain caffeine.

Science of Sport: Caffeine News - The Truth About Caffeine and Dehydration

Written by: Kipp, CTS Senior Coach, NASN Master Nutritionist For many people, caffeine consumption is more than just a habit - it’s a part of every day life we just can’t live without. Our morning latté and coffee fix, the afternoon soda, the evening coffee or tea, those pick-me-up chocolates we sneak at our desk each day around 3pm, and then again before bed; it all adds up. Yikes! Estimates are that as much as 80% of the modern population has a caffeine “addiction,†meaning we are overwhelmingly compelled to have our caffeine “fix†on a regular basis. So what is caffeine, really, anyway? Caffeine is a very rapidly absorbed compound that stimulates both cardiac muscle and the central nervous system in a variety of ways. Many of us associate caffeine with the desired effects of mood enhancement, increased energy and alertness, reduced fatigue, and enhanced athletic performance. However, too much caffeine can be related to less than desirable results: upset stomach, insomnia, nervousness, headaches, caffeine dependence, bone loss, and dehydration. As athletes that consume caffeinated products on a daily basis, the reported dehydration effects are of most concern to us. We hear it all the time - avoid coffee and soft drinks in order to avoid the detrimental affects of dehydration, especially during exercise. But should this really cause us concern and is it really necessary for us to put ourselves through the shakes and shivers of withdrawal in order to cut back on our morning cup o’ Joe? Caffeine intake certainly acts as a diuretic (as does alcohol), signaling the kidneys to increase urine production. Without a subsequent boost in total fluid intake, you create a fluid imbalance in the body, resulting in dehydration. We all know this is bad news; just a 2% reduction of fluids in the body can result in performance decreases of up to 15-20%. That certainly adds up! Without proper hydration, we feel tired and fatigued, grumpy, even nauseous - not to mention disappointed in our performance. That being said, it makes sense that active people and athletes may benefit from avoiding caffeine. However, there is more to the story of caffeine. While caffeine may lead to fluid imbalances by encouraging an increase in urine production, this result only begins to occur with doses of caffeine of over 300-600 mg. In fact, most of the studies involving caffeine and dehydration used supplement doses of over 600 mg in subjects not accustomed to consuming caffeine in the first place. Average daily intake of caffeine these days is about 250 mg (3-4 strong cups of coffee or 6 cups of tea). And, the more caffeine you consume, the more tolerant your body becomes to any dehydrating effects. So, those of us who are a first name basis with the local Starbucks baristas may not even be on the cusp of any sort of fluid imbalances. Additionally, research shows that when athletes (and average individuals as well) are instructed and encouraged to cut down on their caffeine consumption, overall fluid consumption drops considerably as well. The morning cup or two of

coffee and the afternoon sodas are not replaced by water (a far better hydrating source); they aren’t replaced at all! The fluid we were drinking in our caffeinated beverages is forgone altogether, which absolutely leads to fluid imbalances and thus dehydration. So, for the caffeine addicts among us, this seems like great news, right? Well, yes and no. As always, it is recommended to consume about 10-12 eight-ounce glasses of water each day, in addition to the 16-24 oz. of fluid that you should be consuming during every hour of exercise. Morning and midday caffeine fixes can be part of this overall fluid intake. But, at the same time, we also need to watch where that caffeine is coming from. Lattés, cappuccinos, hot chocolates, Big Gulps, etc., are all caffeine sources that carry with them lots of extra calories and not many beneficial nutrients. The milk in many espresso drinks is good for you, but there is often a lot of added sugar you don’t necessarily need. Sodas deliver a lot of sugar, yet they are nearly devoid of beneficial nutrients and may even contribute to losses in bone mineral density by upsetting the body’s calcium/phosphorous ratio. Every once in a while, researchers discover that a once-vilified substance or practice actually isn’t as bad as they originally believed. Such is the case with caffeine. Dehydration results more from low fluid intake than from the consumption of caffeinated drinks, and considering that the vast majority of Americans don’t take in enough fluid every day, drinking more is a good goal, even if some of your choices contain caffeine. Moderation, however, is important; you should still be consuming more water than espresso. Kipp is a NASN Master Nutritionist and Senior coach with Carmichael Training Systems. She can be reached at akipp@....