How should you Monitor your Heart Rate?

Unabridged column Run&Bee published in Hindustan Times on 20th September 2019

Week 65: How should you Monitor your Heart Rate?

In April 2018 I was invited to be a panelist for NDTV Tech conclave. I wrote ‘How Technology Is Reshaping The Fitness Industry’. It’ll help you to read that along with this piece to have a 360 view as in this blog / column I don’t speak much about technology.

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Long before heart rate was a popular term, across cultures and geography, pulse used to be assessed and measured by just a touch. Throughout ages it has been the basic tool to figure how someone’s health is. This art has almost been lost in this tsunami of wearable technology, where, sensing blood, top corporates to start-ups have jumped in. All these gadgets do measure heart rate but do we, from consumers to the experts we put our faith in, have any idea what does that reading even mean? 

Using formulas to measure maximum heart rate and then the experts to tell you what is safe or not has always baffled me. Imagine having a twin sibling who is your exact opposite of you. If you exercise and are active, follow all good lifestyle habits like no smoking, eating well and sleeping on time, how could the same number hold true for that slob of a person with all the bad health habits possible? 

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The problem is when all these multi-billion dollar companies and other aspiring to become one, when they smell blood, they dive deep into it. Like most of healthcare industry today, they have least interest in health or care. One of the assumptions is that technology will help with customised care, but on the contrary it is becoming even more of a conveyor belt approach. 

“The onus is then on you to figure out how to best use that wearable technology you have got hooked on to. Maybe even a more basic question, do you even need it?”

A 2001 article in The New York Times titled ‘Maximum Heart Rate Theory Is Challenged’ looked at the formula ‘220 minus age’ devised in 1970 by Dr. William Haskell and Dr Samuel Fox. They were trying to determine how strenuously heart disease patients could exercise. Dr Haskell is quoted in the article to say that by no means the subjects were meant to be a representative sample of the population as some had heart disease. In any case, it was supposed to be average maximum heart rate instead of an absolute number.

“That was 50 years ago! And all the experts out there have just joined the chorus Baba Black Sheep when it actually was supposed to be White Sheep.”

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But here we are, two decades later, most laboratories in hospitals, sports performance centres and wearable technologies across the world still using this formula for maximum heart rate. 

We need to appreciate that science, where change is the only constant, is always learning.

“Earlier 72 was the magical number for the ideal heart beats per minute. Then we realised that how can whole of humanity just have one ideal number when even horoscope allows 12 categories, so we evolved to adopting a range, i.e. 60-90 beats per minute. Same is applicable to maximum heart rate.”

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While running, 5 minutes per kilometre pace could be easy for someone where as for another it could be just a dream. But as that dreamer starts to put in more hours into sensible running and strength training along with mindful diet, in due course he or she would be running at that pace too. 

Heart rate is exactly like that. It is not absolute. And it is very specific to you at that point of time. In the same Olympics, the three medal winners in a marathon could be able to get their heart rates to a maximum of 190, 160 and  210 respectively. Those numbers would have nothing at all to do with what colour medal those athletes end up winning. 

I suggest a simple way to figure what your specific functional maximum heart rate today is, which again will change as you get fitter or become inactive. As a warm up, jog for 400 metres at a comfortable pace. Then rest for a minute or two. Run the same distance again but at roughly 10% higher exertion. Repeat the same yet again with further 10% higher exertion. Keep doing the same till you can’t go any faster and your heart rate plateaus off. Since doing this first time around will be tricky, I would suggest repeat the same again in a week. This will help you find your very personal number.

While doing interval running, reach a 100% of functional maximum heart rate and maintain it for a kilometre. While doing your tempo, get it up to even 90% for 5-8 kilometres. For longer runs of 10-30 kms, I would look at 80%. Eventually body will be able to maintain it even for the full marathon.

Resting heart rate is an important one but yet again there is no fixed number that is ideal for you. Most people who exercise and run regularly could have their resting heart rate ranging from 40-60. There might be a few who could be slightly above or below this range. Monitoring your heart rate for a month would show you a pattern. It would help you guide in the future what intensity workout you should be doing on a particular day or when should you rest. Besides helping you perform at your peak, it’ll prevent injuries which mostly happen because of over-training. 

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“An ideal time to measure resting heart rate is in the morning 5-10 minutes after having got up from sleep. You can use the heart rate monitor you have or simply count your pulse with fingers of your hand. You could do it the way doctors do on the wrist. Count your pulse for a full minute. ”

What you would have managed by following the above is becoming far more specific and customised to your own needs at your current fitness level than even those very expensive watches.

In 1999, British Journal of Sports Medicine, the top sports medicine journal in the world, published ‘Heart rate of a rhinoceros running a marathon’. Yes, you read that right.

https://bjsm.bmj.com/content/33/5/365

24 year old lady who had run London marathon (42.195 kms) the year before in 3 hours 20 min volunteered to be subject of the study. Her resting heart rate was 52 beats per minute. She ran 1999 London Marathon wearing a Rhinoceros suit. At the start line because of anticipation of the race, her heart rate was 148, a number at which most cardiologists and coaches would tell is dangerous. Then her heart rate fluctuated between 161 and 191 beats per minute averaging at 181 beats per minute. After the race she commented that at no time did she feel overly stressed, apart from the legs feels heavy at 23 miles.

So please understand what those numbers mean rather than trusting those expensive watches you wear. Below is another reason why you shouldn’t just fall for them.

From Dr Kshitij Malik: Fallacies of auto tracker. Both my lowest and highest rates seem to be outliers which are most probably artifacts.

I did a survey on social media a couple of days back where more than a hundred runners of different levels responded. The numbers mentioned both as maximum and resting heart rate were not much of an indication of how good a runner they are. 

I am carrying on the study in a bigger way to have heart rate numbers that’ll give you a better idea what these numbers mean. Please fill the form below, which will take less than you putting your shoes on to help collect some local data to help you understand heart rate even better.

Now go and test it out. Keep miling and smiling.