Judging Physical Exertion
I find that the more tired my leg muscles get while cycling, the more likely I am to get leg cramps. To keep from cramping I sometimes try to dial back my intensity before I fatigue my legs. One way to do this is to judge my physical exertion by how I feel. Here is a simple guide I use based on the Mayo Clinic’s article Exercise intensity: How to measure it
Light exertion – There is no noticeable change in breathing patterns. Don’t break a sweat unless it’s a hot, humid day.
Moderate exertion – Breathing becomes deeper and more frequent. Will break a sweat after performing the activity for about 10 minutes.
High exertion – Will break a sweat after 3-5 minutes. Breathing is deep and rapid. Can only talk in short phrases.
Unfortunately, I’ve found that I can’t always judge my physical exertion by how I feel while I’m cycling. With other types of physical exertion, this method works fairly well for me, but not cycling. Many times, I don’t breathe deeply or rapidly although my body is working harder. While my exertion is the same, my heart rate tends to creep up without me knowing. This has become a real problem while touring because if my heart rate gets too high for a sustained period of time, I fatigue and I get leg cramps.
Knowing My Maximum Heart Rate
I can’t judge my level of physical exertion by how I feel. Therefore, I must rely on a heart rate monitor to gauge how hard my heart is working to help me to avoid leg cramps. However, to use a heart rate monitor, I needed to know my maximum heart rate first. The commonly accepted way to calculate maximum heart rate is this simple formula:
220 – age = maximum heart rate
For example, let’s say I am 65 years old, subtract 65 from 220 to get a maximum heart rate of 155.
Maximum heart rate is the maximum number of times my heart should beat per minute during exercise. See the Centers for Disease Control and Prevention article Target Heart Rate and Estimated Maximum Heart Rate. Nevertheless, not everyone at the same age has the same maximum heart rate. I’ve found that my maximum heart rate has always been a little higher than what this formula gives me.
Knowing my maximum heart rate along with the ability to monitor it greatly helps me take steps to reduce my heart rate before I get fatigued and get cramps.
Lowering My Heart Rate
While I sometimes find it necessary to dial back my intensity before I fatigue my legs, I’ve found it is much wiser for me to calculate and maintain a desired target heart rate zone at which I can sustain my heart rate over long periods in the saddle without overworking it. When I do see my heart rate creeping up, I’ve found that there are three additional steps that I can take to lower my heart rate and avoid overexertion.
Breathing deeply – One of the reasons I can’t judge my physical exertion is that I don’t always breathe deeply when I am at a high heart rate. Consequently, I monitor my heart rate and force myself to breathe deeply when it increases. Sometimes just consciously focusing on my inhaling and exhaling works for me. However, when that doesn’t work, one of the most effective ways I’ve found to breathe deeply is to try to completely exhale all the air from my lungs. This technique forces me to take in a large quantity of air when I inhale.
Stay hydrated – As I mention in my pervious post Cycling During Heat Advisory Warnings I drink plenty of water. To make sure I keep drinking I set an alarm to sound at the completion of every mile. This reminds me to take a sip of water. The rule of thumb to stay hydrated is to drink a water bottle every hour when cycling. This technique makes my intake of a sip of water just the right portion size for my body to easily process.
Fuel My Legs – Similar to my alarm to remind me to drink, I also set an alarm to remind me to consume some carbohydrates to fuel my legs. I prefer whole foods like apples, oranges and bananas, if I can find them. However, I do carry processed carbohydrates such as GU if I can’t find anything else.
I hope you will have the same success at eliminating leg cramps as I have with these simple techniques.