I enjoy training with one of my athletes in particular, since we are closely paced. This allows us to both stay in our heart rate zones without having to modify our work outs or wait on each other. We recently met on a warm and humid morning and began a tough brick work out. Right off the bat her heart rate was significantly higher than our normal discrepancy which is about 10 beats, and her pace was slower. Our disparity only increased as we continued our work out and her performance continued to decline.
After about a half hour I began to question her regarding recovery, sleep, soreness, stress, antihistamines, etc. — anything criteria would affect heart rate. When I got to the hydration question; bingo, it turns out she had not had any fluids to speak of that morning.
The longest period we go without hydration is when we sleep. It is not unusual for the average individual to go 10 hours or more to the next fluid intake; which may be a cup of coffee. We may wake up in a dehydrated state and begin our work outs with a strike against us. Dehydration means low blood volume. Your heart has less fluid to work with and it has to pump faster to supply working muscles. A higher heart rate with lower muscular output (speed or power), is not something an athlete desires from their work out.
The good news is this can easily be prevented. On a hot and humid day start your hydration as soon as you wake up with 16-20 ounces of fluids. Fruit juices and other fluids can count towards this. If you work out is not for several hours consume another 16-20 ounces pre work out. Clear urine output is a good sign, but vitamins, especially B vitamins can affect this. One of the easiest strategies to ensure hydration habits is to keep a case of water in your vehicle.
Training is not just about getting the work out done; it is about getting the best quality work done. If you are not fueled or hydrated properly, this quality can not occur. In the case of my partner after 45 minutes on consistent hydration her heart rate began to fall. By the end of our work out her pace had increased by over a minute, her heart rate was about 10 beats lower. She was able to train hard once again.
Posted: October 11, 2006