By Dr. Lisbeth Hoyt PT, DPT, CSCS
At the beginning of January I woke up and headed to Custom Performance for my usual Saturday morning run with Streets 101. My hear rate was a little elevated but I was rushing a little bit so didn't think much of it. As soon as we set out to run I knew something was wrong. My heart was pounding and within a few blocks, my watch read 180 beats/minute. Not fully trusting my watch, I stood on the side of the west side highway and checked it myself. 175 beats/minute; way too high for the length of time I had run at that point. I turned around to head back to Custom, but running was becoming difficult and my legs felt like they didn't want to move.
3 hours later, I’d eaten a meal, had water with electrolytes, showered, and rested on the couch, and my heart rate was still 125 beats/minute. I (reluctantly) went to Urgent Care to get it checked out, which resulted in a now normal heart rate but abnormal EKG and referral to a cardiologist. Of course this was a Saturday so I spent the rest of the weekend on the couch, trying to not over exert myself and waiting to see a cardiologist on Monday.
Very long story short; I wore a heart monitor for the next month to record any "cardiac events" that would be classified as abnormal. Contrary to my original episode, the heart monitor revealed that I have an extremely low resting heart rate, including up to 4 seconds of no electrical activity while I'm sleeping. The cardiologist has assured me this is a normal occurrence, especially as a runner. While I'm not overly concerned, I'm definitely paying closer attention to my heart rate on a day to day basis.
Since I was left with no actual answer of why this first event happened (all my bloodwork was also normal), I came to my own conclusion with my PCP that I was extremely dehydrated. This was the week after NYE after ali! Cardiac output is the volume of blood you heart pumps per minute or heart rate x stroke volume. Simply stated: if the volume of your blood decreases, your heart rate needs to increase in order for your heart to continue to perform the same amount of work. This equation becomes more important with exercise since you're elevating your heart rate intentionally (and sweating).
My goal of sharing this personal story with all of you is to remind everyone just how important hydration is, especially when running! With the cold winter months, we're less thirsty and tend to drink less water overall, which can be detrimental to those of us training for spring races... or training for life! If you're like me, and sometimes forget to increase your water intake asyour miles go up, try setting a reminder on your phone and carrying a water bottle with you at all times. Remember: if you wait until you're thirsty to drink, you're already a little dehydrated.
See our previous blog regarding ACSM Position Statement on hydration guidelines to make sure you're getting enough fluids before, during and after workouts!