Do you have a nutrition plan? That's the more important question really.

A Coke here or there won't hurt you, but if you are putting down a few a day that's 100's of empty calories from high fructose corn syrup.

You're good then. Just drink plenty of water too. There's not enough caffeine in soft drinks to have a significant diuretic effect. As for the artificial sweeteners, that's a whole other can of worms with opinions ranging from "harmless" to "you're going to get a giant brain tumor".

At one point I was drinking a gallon of Diet Coke a day. Me brane still gud.

Now I have normal human quantities, like one every day or so... maybe less.

I haven't been able to give up Coke and I don't do the diet kind.  That doesn't mean it was a good idea for me to not give them up.  It really depends on your aspirations.  I did an HIM last year and just tried to be smarter about my eating habits rather than having a real specific nutrition plan.  I'm sure I would have done better had I been more rigid in that area.  That said, I had a great experience so I am not sweating it.  I'm just thinking harder now about adopting that approach.

Hope this helps.

willow - 2007-02-09 4:00 PM I am truly addicted to Diet Coke. I just try to drink water too. One water bottle-one diet coke

You know, I haven't had one today and now I'm digging around in my desk for nickels and dimes... thanks.

I love my diet coke- just try to make sure I get my water too. I drink a diet coke before every long run and race and it works for me! Just had a half mary PR after 75% of a 20oz diet coke and snickers low carb marathon bar. I'm sure it was the diet coke....

Everything in moderation. When I start my HIM training I will probably limit it to 2 a day, water after that.

  No one said you have to give up Coke. Do what you want, you're an adult right?

I've heard lots of arguments for/against.  I was one of those people that drank SO much diet soda I didn't think I'd ever quit.  REALLY thought I was addicted.

Well, I stopped.  The trick for me was to drink water with lemon juice in it.  As long as it has flavor I seem to be okay...

Anyway...you can quit.  I promise you can.

For my 1/2 IM last June my coach had me do a caffeine depletion phase the week before, with the idea being that doing so would allow me to get some performance enhancement from caffeine on race day. I chickened out on the caffeine on race day other than one cup of coffee. I hadn't practiced taking caffeine in training, and it was a potentially going to be very hot. I plan to do it this year, but I will practice it a month or two out, depleting for a week and then supplementing caffeine on a long brick workout.

FWIW, you can carb deplete as well, and then when you carbo load 48 hours out you can load up your muscle glycogen more effectively. Carbo loading has less benefit when your muscles are already tanked up on glycogen. There's literature to read and review, and that's the way to go. Don't just take anonymous internet advice (from me).

Let me see if I can find the information on it and I'll send you a link.

An article my coach sent me last season: 

The facts about caffeine and athletic performance

The truth is, a moderate intake of coffee, cola and other caffeinated beverages does count towards fluid needs -- particularly if you're accustomed to consuming caffeine on a daily basis. (Don't we all know someone who drinks only coffee -- no water -- and is fully functional?)

Given that about 80 percent of Americans drink coffee (55 percent daily, 25 percent occasionally), and the average intake is about 200 mg caffeine/day (3 mg/kg), most athletes are familiar with caffeine's benefits of heightened alertness and performance.

The U.S. military is intensely interested in the physiological effects of caffeine on hydration. With soldiers enduring the heat of Iraq, the military needs to know how to optimize hydration. Hence, they have researched the effects of moderate and high doses of caffeine (3 and 6 mg/kg body weight) on hydration.

Using subjects who habitually consumed a relatively low amount of caffeine -- equivalent to one, six-ounce cup of brewed coffee (100 mg/day; about 1.3 mg caffeine/kg), they found no detrimental effects of caffeine on 24-hour urine volume. (Armstrong, In't J Sports Nutr, June 2005) By day's end, the urine losses were similar whether the person consumed no caffeine or a high dose.

How did the "coffee is dehydrating" myth start? The initial studies looked at urine collection just two to four hours after caffeine consumption (not the 24-hour picture), didn't compare coffee to water, or used very high doses of caffeine. We now know people have similar urine volume whether they consume caffeinated (<3 mg caffeine/kg) or plain water.

Caffeine and performance

Caffeine is one of the best-tested ergogenic aids (substances, devices, or practices that enhance an individual's energy use, production, or recovery) and is known to help athletes train harder and longer. Caffeine stimulates the brain and contributes to clearer thinking and greater concentration.

There are more than 74 good studies on the use of caffeine for both endurance exercise and short-term, higher intensity exercise. The vast majority of the studies conclude that caffeine does indeed enhance performance and makes the effort seem easier (by about six percent).

The average improvement in performance is about 12 percent, with more benefits noticed during endurance exercise than with shorter exercise (eight to 20 minutes) and a negligible amount for sprinters. More benefits are also noticed in athletes who rarely drink coffee, hence are not tolerant to its stimulant effect.

Because each person responds differently to caffeine, don't assume you'll perform better with a caffeine-boost. You might just end up nauseated, coping with a "coffee stomach," or suffering from caffeine jitters at a time when you're already nervous and anxious.

And be forewarned: While a morning cup of coffee can assist with a desirable bowel movement, a pre-competition cup might lead to transit troubles! Experiment during training to determine if a caffeinated beverage or plain water is your best bet.

Caffeine and sports beverages, sports supplements

As you have likely observed, caffeine is readily available in a variety of products: