Calorie measurement for performance

Calorie measurement for performance

Performance measurement used to be easy - you went fast and a mate timed you. Now we’ve got enough data to flummox a 1980s rocket scientist yet simple calorie measurement is all too often overlooked. But when used properly, it’s an easy win for all of us

Never the good-looking singer or edgy lead guitarist in the performance metric lineup, the calorie’s more like the seasoned bass player plugging away in the shadows. No one’s asking for his autograph, but take him away and the band falls apart.

Calorie measurement - lighter is faster

If you think that sounds dramatic, remember that simple calorie management is the biggest (and cheapest) upgrade 90% of runners, cyclists or triathletes can make. Power to weight is everything in endurance sports and the heaviest part of any race day package is always the athlete.

Rob Kitching of Cycling Power Lab explains simply:

 “A quick win is to lose weight for better performance”.

This applies to pros as well as amateurs, as Bradley Wiggins describes perfectly in his 2012 autobiography, ‘My Time’.

“It [weight loss] is the most effective way of improving your performance on the road: one kilo less bodyweight means you gain about 25 seconds for a given power output on a 30 minute climb… it’s not just about the climbs; every time you accelerate out of a corner or up a little hill you are hefting that extra weight. Over a three week race those efforts amount to a huge amount of extra work.”


calorie measurement bradley wiggins

Drop one kilo of bodyweight, gain a free power upgrade as power-to-weight improves. Smart weight management was a core part of Bradley Wiggins’ performance toolkit in taking Olympic Golds, Tour de France victory and the hour record

Calorie measurement - accuracy is everything

But before you rush off to bin your biscuits and leap into a life of lettuce and quinoa, you need to make sure you’ve got the right calorie data coming in first to get the right results coming out.

The gold standard in calorie measurement is indirect calorimetry. As Dr Jason Gill of Glasgow university’s Institute of Cardiovascular and Medical Sciences explains:

“This involves collecting the air you breathe out during exercise to calculate the oxygen your body is using and the amount of co2 the body is producing. This allows us to calculate total calories burned, and the ratio of carbs and fats burned. This is because when you burn fat you produce less carbon dioxide than when you burn carbs”.

If this all sounds like far too much hassle and you don’t just happen to have a full sports lab at your disposal, don’t fret - when used properly the calorie counting feature on most decent multisport watches or activity trackers will do the trick nicely.


Calorie measurement data

The devil’s in the data - great data into your watch or fitness monitor will give great data out

These aren’t perfect - a recent test published in the journal of the American College of Sports Medicine found they have around a 10% inaccuracy when compared to indirect calorimetry - but when programmed correctly these can deliver all the data you need for great results.

“In an unfatigued state there’s a linear relationship between heart rate and oxygen uptake,” says Gill, “so from heart rate you can calculate calories burned and these watches will give you a ballpark figure”.

“But dehydration and heat can both increase your heart rate and will affect those figures without actually changing your calorie use”, he adds.

Calorie measurement desert


Heat affects calorie figures, and so does wearing your shirt like a cape…

Also, the heavier you are, the more calories you’ll burn.

“At 60kgs someone will be expending roughly five calories a minute, at 100kgs that’s gone up to eight calories per minute,” explains Liz Shenton, performance and training manager for Polar.

Put this all together and getting reliable data from your calorie counting watch sounds challenging. But it’s not - the key is to feed your device as much data as possible:

“More accurate info means more accurate readings,” says Shenton.

“Systems that don’t ask for your gender, height or basics like that are really estimating [calorie count]… the more complex ones ask for these plus resting heart rate, activity level, VO2 max and more.

“Watches with barometers can compensate calorie use for altitude loss or gain and can also be set to work for different forms of exercise – cycling and running for example will be very different in terms of energy used over time”.

Fill your device with all the data it asks for, use different sport modes for recording when they’re available, and you can expect great calorie figures to work from. Now you’re getting awesome calorie data, here’s how to use it…

Calorie measurement - making the data work for you

With the right figures going in, you can now use your calorie data to measure fitness increases, or decreases in the same way you would with heart rate.

Let’s say you burn 500 calories in a session one day, but a month later on the same session only burn 400 you’ve either slowed down (if your time’s slower) or you’ve become fitter and hence more efficient (if your time’s faster or the same).

Add weight to the equation, allied to common sense (weight loss is all very well, eating disorders and passing out mid-session are not) and you’ll be able to start learning your optimal racing weight as increased strength and speed start matching up with increased calorie efficiency.

Calorie measurement - conclusion

In a nutshell, calorie measurement’s another mighty handy part of the performance toolkit.

Closing words here go to Kitching: “calorie measurement all falls into a wider message that what matters is the quality of your training, not the quantity”.

However you measure calories, don’t forget quality while you’re at it

When results matter, make sure every calorie counts and smash the nutrient density and variety of your athletic diet through the roof with 33Fuel’s unique Pre and Post Workout Shakes and groundbreaking Chia Energy Gels. Both will maximise the returns on your training, speed up your recovery, and keep you firing strong, fast and happy no matter what life and sport throw at you. Happy training one and all! 

Make your calories count when it matters - our Race Weekend Bundle has you covered with the perfect nutritional punch to power up your biggest races and ace your recovery afterwards

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