This might help put to rest any caffeine controversy.
From
http://www.t-nation.com/readTopic.do?id=694639 :
"Role of Nutritional Supplementation on Energy Expenditure, Athletic Performance, and Body Composition — Dr. Greg Haff, Dr. Joel Cramer, Dr. Joan Eckerson
This portion of the pre-conference symposia was sponsored by GNC. The main supplement covered was a new high-tech substance known as "caffeine." A GNC rep was even handing out free samples of this cutting edge drug in the form of Thermo Burst.
I was clearly about to burst with excitement.
Sitting in my front row seat and damned near bouncing up and down with anticipation and unfettered glee, here's what I learned about this futuristic "caffeine" stuff:
- Caffeine is the most commonly used drug in world and it occurs naturally in over 60 plants. The average American gets 200mg per day. Six ounces of coffee contains about 100mg.
- The orgasmically exciting and revolutionary supplement Thermo Burst contains 201mg of caffeine and a bunch of miscellaneous herbs that seem to have nothing much at all to do with fat burning.
- Decaffeinated coffee still has a couple of milligrams of caffeine, but not much.
- Caffeine increases urine production, stimulates the nervous system, relaxes smooth muscle, activates cardiac muscle, and increases gastric secretions. Serum concentration in the blood reaches its peak 30-60 minutes after ingestion and its half-life is 4-6 hours.
- Caffeine usage is banned by some sports organizations, yet one study (Graham, 2001) showed that urinary concentrations are variable and inaccurate for determining caffeine intake. Just an FYI, 13mg/kg caused 66% of athletes to fail a drug test. Other studies using 5mg/kg and 9mg/kg didn't cause a failed test.
- During moderate to high intensity exercise, caffeine has been shown to improve muscle contractility, work output, time to exhaustion, and performance. Not all studies show these positive benefits but most do. There are some people who are non-responders to caffeine, so that may be why some small studies show little benefit.
- 330mg of caffeine helps cyclists get a 19% increase in time-to-exhaustion trials.
- Interestingly, a study on distance runners showed that those receiving large doses of caffeine (9mg per kg of body weight) didn't show improvement. Those taking smaller doses did.
- 150mg of caffeine has been shown to improve long term memory and other cognitive functions.
- Caffeine is good for most endurance athletes, but how about anaerobic athletes? It gets fuzzy here. Most studies presented showed benefits, but a few didn't. However, to analyze the effects on short term, high intensity exercise, mainly studies on cyclists are used, so we weight trainers usually have to extrapolate from that.
- Caffeine increased maximal power output and decreased perceived exertion in hard cycling bouts. This may be due to what's called the "elation effect."
- One study showed 201mg of caffeine increased bench press 1RM, but not leg extension strength. (Yeah, like we care about our 1RM leg extension anyway!) The studies conducted so far on caffeine's effects on strength are inconclusive. One problem may be that hand grip tests are usually used in the studies.
- In sprint swims, untrained swimmers showed no increase in performance using 250mg caffeine. However, trained swimmers showed an increase in swim velocity. One theory is that caffeine works better for experienced athletes and exercisers. They're simply more responsive to it than couch spuds.
- Caffeine has a greater effect on metabolism (caffeine induced thermogenesis) in lean women compared to fat women.
- There have been studies to see if caffeine has a positive effect on weight loss, but the problem is the supplements studied also contained other ingredients, making the results questionable. However, it does look like caffeine has some effect on resting energy expenditure.
- At least one study showed that caffeine-containing green tea worked better than caffeine alone for increase energy expenditure.
- Smokers are less responsive to caffeine than nonsmokers. Especially when they're dead.
- Capsaicin, the chemical that makes red peppers hot, has similar effects as caffeine. It may lead to enhanced energy expenditure and performance.
- The ergogenic benefits of caffeine are more pronounced when using caffeine capsules than coffee. Other compounds in coffee may moderate the effects of caffeine.
- Adverse effects of caffeine (over 500mg) can cause mood shifts, headaches, and fatigue as part of withdrawal. However, this amount has been shown to keep reporters awake during GNC-sponsored supplement presentations.
- Fears of dehydration associated with caffeine use are unjustified. Caffeine doesn't cause dehydration.
- Caffeine suppositories have been used by athletes. Sorry, no photos available.
- One of the presenters told an interesting story about how one of his lab mates was accidentally given ten times the toxicity level of caffeine and had to have his stomach pumped. Amateurs. It ain't a party until someone gets his stomach pumped!
- Some studies show that caffeine taken before exercise doesn’t burn more fat based on certain chemical markers; however, people do report this effect in the real world. What's going on? Well, it may be that exercisers simply perform more work in the gym when using caffeine.
- Caffeine can decrease pain induced by exercise. It also decreases our force sensation. So, we can train harder without feeling like we're training harder. Caffeine seems to affect how we receive and perceive pain."
So there you have it folks; before important bouts, weight training, and most definitely any cardio work, slam a Red Bull spiked with Dave's Insanity Sauce.
darius
.... but there so much protein in bug parts.
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