Since today is maybe the hottest day of the year (at least so far) here in the Pacific NW, I thought it was a good opportunity to remind everyone about hydration. Once again, this is "do as I say, not as I do" advice as I can sometimes be a bit lax in my own hydration efforts and my runs definitely reflect that... see below and my run from today which was actually slower than my long run on Monday! Agh! I struggled to get a full 7 miles in and it was nowhere near a personal best time for me. Anyway, I digress.
When you hydrate properly before a run and then during a run (or whatever is your workout of choice), you will perform better and stave off dehydration and it's effects. According to the April 2010 Journal of Athletic Training, dehydration causes your body's blood volume to drop which in turn can impact its ability to transfer heat efficiently which then forces your heart to beat faster thus making it difficult to perform at your peak aerobic form... who knew???
Along with effecting your performance, dehydration in milder forms can also cause muscle cramps which will also impact your workout. In more severe forms in can result in heat exhaustion or worse, heat stroke. Your body can go into shock and it can even cause kidney failure. So, in an effort to avoid even the least of these problems, take some elementary precautions and preparations for your run/workout.
One to two hours before your workout, try to drink 8 to 16 oz of water or sports drink to make sure your body is fully hydrated when starting out. Then, during your run, you should make a point of drinking 3 to 6 oz. of fluid every 15 to 20 minutes. For days that I run on the treadmill, this is pretty easy for me to do... I just watch the timer. On days that I run outside, it's a little tougher, but I still usually have my running watch timer going and I just try to keep it to drinking on the 20's or a little before (20 minutes, 40 mins, 60 mins, etc). Be sure to drink small amounts frequently. This will help your body to better absorb the fluids that it needs and will also help your tummy to keep from sloshing (Ew! I hate it when the happens!).
Of course, these are just general guidelines. Many athletes will take the additional step to determine their own body's specific needs. You can do that by weighing yourself (naked) before your run and then weighing yourself after your run (go ahead and hydrate as you normally would during the run). Once you determine how much weight your lost during the run, you will know approximately how much fluid you sweated off during that run, thus how much more fluid you need to be consuming. According to the American College of Sports Medicine, you should gear your fluid intake so that you lose no more than 2% of your overall body weight during a workout. Anything greater than that will begin to affect health as well as performance.
For more information on this topic, check out the Runner's World online article. And whatever is your sport of choice remember to stay hydrated!
Monday's (Long) Run