jumpIf you love to run, bike, swim, skate, walk, play sports or be active in other ways outdoors, then you probably already know how hot you can get on warm and humid days, which can make exercise feel like it takes more effort. Awhile ago I reported that this tendency to heat up gets even more intense during the second half of your menstrual cycle (starting the day after ovulation and lasting through the day before your next period) due to a rise in progesterone, which bumps up your core temperature slightly.

Now I have a bit of a follow-up to share: According to study in the Journal of Sports Medicine and Physical Fitness, rehydrating with water as you exercise during the second half of your cycle counters some of this progesterone-fueled temperature increase, helping you stay cooler than if you didn’t drink up. The result: You feel more energized and don’t tire out as quickly.

You probably already know it’s important to stay hydrated when you’re active and sweating a lot, especially in high-temperature conditions. Now this research gives you one more reason to keep a bottle of water or your favorite sports drink nearby when you plan to exercise in the heat.

[Photo: lindstrand]