You're trying to avoid sugar. Fortunately there are plenty of sugar-free sodas to choose from. What harm can drinking a diet soda do? According to a study published in the Journal of General Internal Medicine, you might end up 43% more likely to suffer a vascular event if you drink more than one diet soda a day. Vascular events include strokes and heart attacks.
Researchers tracked the soda drinking habits of 2,564 New Yorkers over a 10-year period. Those who drank between 6 diet sodas a week and one a month were no more likely to have increased odds than those who drank regular sugar-sweetened pop. But subjects who consumed more than 6 diet sodas a week significantly increased their odds of adverse vascular events. More research is necessary, but you might want to start tracking diet cola consumption in your nutrition and training journal.
