QUESTION: What is the 75 rule in cycling? I heard someone telling his buddy to remember that rule on a group ride as the pace started to pick up. What did he mean? —Pete L.
RBR’S STAN PURDUM REPLIES: The 75 rule is a training guideline for riders who are seeking to improve their performance and endurance. The “75” is a percentage and the so-called rule is that when training, about 75% of your time should be at or below 75% of your maximum heart rate (MHR), which is the highest heart rate you can achieve. Conversely, only about 25% of your time should be spent working intensely above 75% of your MHR.
The theory behind the rule is that by staying below the 75% of MHR threshold most of the time, you’ll be able to train overall at a higher intensity without overdoing it and injuring yourself.
Our MHR changes as we age. To calculate your MHR for your current age, subtract your age from 220. For example, for a 60-year-old person, the estimated maximum age-related heart rate would be 220 – 60 years = 160 beats per minute (bpm). That, as I said, is an estimate, which can be affected by health factors, but it is a place to start. The 75% threshold would be: 0.75 x 160 = 120 bpm.
If you wear a heart rate monitor when you ride, your MHR is likely to be the highest number displayed on your monitor over the last year. And realistically, a heart rate monitor is the only way to constantly know where you are in relation to the 75% number, as your current rate is displayed while you are riding. Otherwise, you must stop periodically and take your pulse for 60 seconds at your neck, wrist or chest.
But a lot of trainers say that obsessively watching our MHR is irrelevant, especially as we age. See, for example, what RBR’s Coach John Hughes says about this.
In terms of the guy you heard telling his buddy on a group ride to remember the 75 rule as the pace started to pick up, he was probably speaking loosely to mean “Don’t blow the socks off the rest of us!”
For more about heart-rate-based training, see Arnie Baker’s RBR article here.
Stan Purdum has ridden several long-distance bike trips, including an across-America ride recounted in his book Roll Around Heaven All Day, and a trek on U.S. 62, from Niagara Falls, New York, to El Paso, Texas, the subject of his book Playing in Traffic. Stan, a freelance writer and editor, lives in Ohio. See more at www.StanPurdum.com.
Every body is different and 220 minus your age has no basis in reality. You may as well use a random number generator to guess your max HR.
I have to subtract 17 from my age to get that formula to result in my max HR. I have friends who have to subtract substantially more than that to get the formula to match reality.
syborg is absolutely right. The 220-age formula was NOT based on any scientific research, and was never intended to be used as a guide to athletic training by its authors (Haskell & Fox). I agree with Coach Hughes that guiding training by perceived exertion is far better than blindly following a formula based on ‘220-age’ HR.
Much better is the Nes formula of 211-(0.64 x age). It was published in 2013 from an ACTUAL STUDY of over 3300 adults.
HOWEVER max HR is VERY individual specific, and can vary 20-30 bpm (or more) even amongst highly trained athletes. Even the Nes data indicated their formula was rather rough (standard error 10.8 bpm, suggesting that almost 1/3rd of folks will have max HR will be MORE than 10 bpm different than the formula’s prediction). For those interested (obsessed?) with determining their personal actual max HR it may be best to seek professional/medical assistance in doing so.
A well known pro (x-pro now) once explained it to me as the 80/20 program (rule, whatever).
And some of us fit the 220-age formula closely, determined on treadmill and cycling ergometer.