Activity Trackers for Weight Loss are Probably a Waste of Time

Tracking calories burned is probably a waste of your effort if you’re trying to lose weight.  Let me start off by saying that I didn’t always feel this way.  In the past I made a video promoting the Fitbit Zip and have personally used the Fitbit Zip, Polar heart rate monitor, and a MIO Slice activity tracker.  My wife uses a Garmin when we hike.  When people started writing off Fitbit a few years ago, saying they were dead, I wrote an article stating that Fitbit was alive and well in the Weber household!

Activity Trackers (i.e., Fitbit, Apple Watch, Polar, and Garmin) do a number of wonderful things including measuring heart rate, time, distance, elevation, sleep, steps, and exercise intensity.  They may also “nudge” you into breaking up your sedentary behavior (i.e., getting up from your desk).  There are numerous health benefits to an activity monitor (wearable device), but I don’t find the calorie expenditure feature to be terribly helpful for weight loss.  Nor do I find the calorie feedback from exercise machines (i.e., treadmill, stationary bike or elliptical) to be worthwhile.

It can be super fun knowing your “stats” like you are playing your own little video game, competing against yourself and other players.  But just because we can measure something doesn’t make it meaningful.  I really wonder how many people change their exercise behavior in a meaningful way on the fly because of an activity tracker.  People tend to use exercise like a “get out of jail” card but it just doesn’t work that way.  It’s way too hard to burn calories and far too easy to eat them.

I’m not a huge fan of tracking calories burned but I do think that tracking energy intake (food calories) is an absolute must to lose weight.  You might be asking yourself; how does this guy think input is so important that you HAVE TO TRACK CALORIE INTAKE, but when it comes to calories burned, meh, who cares?  After wrestling with this topic for a bit, here’s what I came up with.

  1. To lose weight you need to incur a negative energy balance. This means that you eat/consume fewer calories than you burn/expend.  You’ve been told that if you create a negative energy balance that you will lose “x” amount of weight per week (depending on the deficit) and after “x” number of weeks you will reach your goal weight.  Conceptually, this type of thinking is helpful, realistically, it is flawed.

Weight loss does not occur in a linear fashion and calories cannot be micromanaged (gamed) to suit your weight loss goals.  I have provided a detailed explanation of this elsewhere but in a nutshell, calories matter but the body is not a simple continuous input/out machine.  Its calorie needs change as weight loss occurs (and so does your behavior).

  1. Diet and exercise are the cornerstones of any good weight loss program; however, diet is MUCH more important than exercise to lose weight. Diet and exercise are always mentioned together, inferring that diet and exercise contribute equally to weight loss.  However, this is not the case.  Diet and exercise are not even close to being equals.  Diet definitely wears the pants in the family.  For that reason, it is of utmost importance that you meal plan like crazy and track your calories (food log; MyFitnessPal).
  1. The reason diet is more important than exercise to lose weight is simple mathematics. It is extremely easy to consume calories but very, very difficult to burn them.  The example I like to use is that of competitive eating champion Joey Chestnut who can consume twice as many calories in 10 minutes (20,000) than an ironman athlete expends (10,000) in 10 hours of high intensity aerobic activity!  There are countless other examples that you and I encounter every day.  Just think about how many miles you have to run to burn off a couple of cookies that took you only seconds to eat.
  1. But let’s say you don’t want to listen to me and still want to track your exercise calories. Wouldn’t you want to choose activities that burn the greatest number of calories?  If so, you are going to have a high bias towards prolonged, continuous aerobic activities utilizing large muscle groups that you can do for hours such as road cycling, cross country skiing, marathons, or triathlons.
  1. If calorie burning is your goal, virtually no one in their right mind would resistance train. While aerobic activities engage larger muscle groups at moderate to high intensities continuously for sometimes hours at a time, resistance training is a very high intensity exercise for seconds and then resting for minutes.  The rate of energy expenditure (calories burned) is much greater for resistance training during the actual contractions but with so much rest between sets, aerobic training is going to beat resistance training 10 times out of 10 when it comes to burning calories.  For those who say that resistance training builds lean mass and lean mass burns calories at rest.  Yes, this is true but not as much as a healthy bout of aerobic activity burns.  Aerobic activity still wins the calorie burning battle.
  1. In addition to resistance training there are numerous other physical activities (see table 1) that won’t be as appealing to the calorie counter/chaser. The danger here is that you may be tempted into pursuing activities that you don’t really enjoy just because they burn the greatest number of calories per session focusing on a narrow, niche segment of exercise.  If you enjoy doing continuous aerobic activities and can afford the cost of entry (bikes are expensive!!) then you’ve basically won the calorie burning lottery.  There’s nothing inherently wrong with trying to burn and track calories or working towards a goal (weight loss) but I question how sustainable, over the long term, is doing an activity that you don’t enjoy just for the sake of burning calories.
  1. If tracking calories burned during exercise doesn’t matter, then what about total daily energy expenditure from activities of daily living (i.e., showering, getting dressed, brushing your teeth) and non-exercise physical activity (i.e., walking into the office, taking the stairs, standing at your desk)? While everything “matters” the number of calories burned by these activities are so small that they will not significantly contribute to your weight loss (unless you are working in an Amazon warehouse).  I jokingly wrote an article on “The Amazing Chewing Gum Diet to Lose Weight” before, highlighting how focusing on such a narrow calorie burning activity and extrapolating it out to potential weight loss is dangerous.  Some people loved the article, others basically told me to go to hell.

Table 1. The Calorie Burning Potential of Various Exercises. Running is in numerous categories due to the differences in distance and intensity chosen by the runner.  Competitive team sports could burn few or lots of calories depending on the time and intensity of competition.  CrossFit and HIIT (High-Intensity Interval Training) tend to have a 60-90 minute training session, thereby time-limiting these activities from burning the greatest number of calories.  The classifications here are for illustrative purposes (upon the author’s discretion and knowledge of exercise) and are not built upon metabolic equivalents (METs) or another scientific measure of calories burned.

The expenditure part of the calories in/calories out equation for weight loss is of obvious importance.  Yet, weight loss must first start with diet.  Repeat after me, diet, diet, diet.  We need to try to disconnect the association between exercise and calories burned.  Exercise should be prized for its mental, physical, and emotional benefits first and calorie burning as a secondary byproduct or “bonus” not a primary objective.

I think it is also important to remember that an entire industry has been built on selling you really expensive activity monitors (they aren’t cheap and if you read my blog, you’ll know that I just love marketing, no sarcasm here).  Of course, there are many utilities for these devices but I don’t think calorie counting is one of them.  These devices tend to be good at entertaining you, giving you the “illusion of trying”, and may nudge or motivate you in a positive (health) direction but are they necessary or even helpful to losing weight?  It is difficult for me to say yes.

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