The black plague has hit my community, and runners of all ages are dropping like flies. For three weeks now, I’ve been battling a sinus infection turned to a general head and chest cold. Every morning, I play the guessing game with myself—should I do the workout I planned to do, should I alter it a little, or should I just call it a day and try to rest? Training and racing requires that we push through pain to achieve the best performance, but sometimes it’s difficult to tell what pain is ok to tolerate. As they say with most injuries, the simplest and best answer is to listen to your body and use common sense.
For those of us who are a little too neurotic to accept the “listen to your body” solution, the question remains: how can you tell when you can train through a cold or illness, or when it’s best to take a day off or change your workout? I’ll pass along a couple of tips I’ve picked up from coaches and friends. First is “the neck-up” rule—if your cold or illness is affecting your body from the neck up (headache, sinus congestion, itchy eyes, etc) then it’s generally ok to keep training. If your chest is congested or you’re feeling feverish, you should try to rest.
Runners can also monitor their resting heart rate to see if an illness is coming on or if they haven’t recovered sufficiently from a hard effort. The important step is to get an accurate average resting heart rate. For at least a month (better if it’s longer),take your heart rate as soon as you wake up in the morning and average the results. Once you have an average, if you wake up and your heart rate is 10% higher than your average, this could be a signal that you need to take an easy day. I must admit that I don’t actually use this method because I could never remember to take my heart rate when I woke up. But it’s an interesting theory.
Another hot topic in the running community right now is monitoring heart rate variability, which measures the variability in the length of time between heart beats. If your heart rate is 60 beats-per-minute, it does not mean that your heart is beating once every second. Sixty bpm only indicates that the heart will beat 60 times in a minute. Your heart actually beats a little faster as you inhale. HRV is a measure of how much the rhythm of your heart beats varies over a set period of time. Some studies have shown that checking heart rate variability is more accurate at predicting illness or fatigue than tracking your resting heart rate. And now, the same technology that lets you fling angry birds to blow up pigs can help you track HRV.
For $10, you can purchase the iThlete app, which allows you to measure your HRV using an iPhone or iPod touch. To operate the program, you also have to buy the iThlete ECG receiver, which attaches to the phone, for $50, and you need a chest strap (iThlete is compatible with chest straps from other heart rate monitors, or you can purchase an ECG receiver and a chest strap for $75 from iThlete). There is some controversy about the ability of HRV to determine your training program; as with taking a heart rate measurement, other factors besides illness or fatigue can influence your heart rate variability. But many runners and endurance athletes have added this technology to their regiment of wellness practices.