This past Saturday in my “brick” workout…(ride, then run….my last prior to this weekend’s Olympic Distance Triathlon), I couldn’t help but think about how hot it was. While en route to what wound up being a 30 mile ride, I found myself chatting with my two training partners for the day (Derek & Chris) about the heat really starting to drag on me a bit. It reminded me of this past year’s Boston Marathon….you know, that day that it was almost 90 degrees and humid in mid April…in Boston!
After getting off the bike, I started to think about “heat acclimation”….and what a surprise, almost exactly 1 year ago today, after having more unseasonably hot weather….I wrote the below blog
“If You Can’t Take the Heat, Get Out of the Kitchen” – A few tips to stay fit and prevail in the heat ….
First – keep in mind that over 60% of your body is made of water and effective hydration is a key component to allowing your body to cool itself. Actually, if you’ve been reading since the beginning, you might remember me mentioning that some anthropologists believe our ability to cool ourselves via sweat was key in our ability to survive, and when needed, run our prey to death. HOWEVER, also remember that as we sweat excessively we lose liquid and therefore blood volume…adding additional cardiovascular strain (heart has to work harder to get the body what it needs via blood supply), AND we also lose a considerable amount of sodium…and when the sodium concentration in our body is lower outside the cells within our body vs. inside, the body compensates and pushes water into the cells…causing cell swelling. And while some cells can handle the swelling …some don’t do so well…like those in the brain, putting us in a potentially compromised and even dangerous situation. But don’t just rush out and replenish excessive sweat loss with water alone…this might just make matters worse. Read my colleague Justin’s blog for a further explanation of hyponatremia…and know this – dehydration equal to even a 2% weight loss (3 pounds for me) can have a detrimental performance effect…..and as much as a 5% weight loss (7.5 lbs if you weigh 150) has been shown to decrease performance capacity by up to 30%…yikes!
Some simple tips I put into place…keep liquid readily available while exercising in the heat….I drink about 3-5 ounces (few good gulps) ever 15-20 minutes. But taking it one step further…when exercising for greater than one consecutive hour…or possibly even less in excessive heat….consider replenishing with a sports drink that contains the sodium, potassium, and other electrolytes you’ve just sweat out.
Training in the Heat
Don’t be afraid of it, just be smart. It’s important to get acclimated to the heat, but starting out slow and short…some recommendations indicate starting with 10-20 minutes, and working up to about 60-100 minutes over a 10-14 day period. And most research will point to 10-14 full days before your body full acclimates….but what does that really mean?
- Blood plasma increases compensating for the blood volume lost via sweat
- Lower core body temperature…meaning the body has further to go before “over-heating”
- Lower resting heart rate & more efficient cardiovascular system