Quick answer: Exercise is a poor strategy for burning off excess calories — a hard 30-minute workout might only burn 500kcal, easily undone by a couple of festive treats. Limiting intake matters more than exercising it away, though people who lose weight through nutrition are more likely to keep it off long-term if they also exercise.
I’m a fan of the festive season – Christmas songs, carol singing, silly jumpers! However I do think November is too early, and personally don’t get into the swing of things until December. Despite this, I’ve already found myself tucking into the mince pies, does that count? We are entering the season of excess, and although I am a self-confessed health fanatic, I’m also a foodie, and a realist who will definitely allow treats (just as long as they don’t become the status quo).
Why exercise alone doesn’t cancel out extra calories
There is a myth that you can burn off those extra calories with exercise, but unfortunately, it’s simply not true, at least in the short term. Have you ever done a bike ride, run, or frankly any exercise on a machine or whilst wearing a wearable like a Garmin or Apple watch that tracks calories burned? They are not of course perfect measuring tools, but do give us some idea. For example, last week I did a 30 minute indoor cycle, at an average of 200 watts. For those unfamiliar with the units, that’s about 11 miles in length, and on the online leaderboard of all the people who have done that workout, it was about top 10%. A pretty good workout then. How many kcal do you think this burned? Not even 500. A turkey sandwich, mince pie and a satsuma and I’l probably over that!
When exercise can help with weight loss
To exercise enough to ‘burn off’ the extra calories I’ll likely consume in December just isn’t feasible. Biology doesn’t work like that. Whilst exercise is a fundamental part of living well, longevity, disease prevention and so on, it simply isn’t a great strategy for weight loss. A far better strategy is to in some way limit the fuel intake. This could take a number of forms – time restricted eating, intermittent fasting, calories counting would all work. Personally I’m not a fan of calorie counting as it’s just so hard to do accurately. Food labelling just isn’t that good, and not conducive to this approach. I find it confusing enough and have a pretty good understanding of what I’m looking at, and still struggle, so the average citizen I think would struggle.
I said above that this doesn’t work in the short term, but as with most things medical, there are always caveats. About 8 years ago my wife was really struggling with abdominal pain. She had gallstones during her second pregnancy, and got admitted to hospital in London shortly after my daughter was born with acute cholecystitis needing a procedure called an ERCP to fish the stuck stone out. She went on to have her gallbladder out, which whilst all went ok, her tummy was never really the same afterwards. Having seen a number of doctors both NHS and private, she then saw a nutritional allergy expert and we decided to pare back her diet before slowly re-introducing foods to see if there were any triggers for symptoms.
To avoid cooking two meals each day, I followed the same diet, and I have to say, it was pretty bland. By the time we got to rice and chicken most meals I was craving variety. More worrying to me though, was i was losing weight. Regular readers will know I can be a bit of a hypochondriac and this was triggering. Did I have cancer? I honestly struggled to shake the thought. I started counting calories, and tracked my workouts for a few weeks. I think of myself as a pretty bright person, so felt pretty embarrassed to simply see a big deficit between calories in and calories out. I only say this to make the point that there are some circumstances where exercise can contribute to weight loss, but they are pretty extreme.
The bigger picture
There’s also a big difference in the quality of those calories and their affect on health. High protein, whole food is far healthier than ultra-processed food, yet may be less palatable, and often more expensive. After the episode above I hugely increased my protein intake, and surprise surprise, my weight came right back up to where it has been for 25+ years. Thankfully, my wife also found a nutritional approach that means she now has no symptoms, and a diverse diet which we can all enjoy.
In my experience, people who have been able to achieve weight loss through nutrition are far more likely to keep this off consistently if they exercise, and this is backed up in the literature. If you are someone who struggles with this, I would suggest the run up to Christmas is not the time to worry about it too much. However, may now is the time to make some plans for the new year? More on this in upcoming weeks.