For a long time calorie counting was seen as the gold standard way to manage diets. Lulu Hunt Peters pioneered the concept of calorie counting and restriction as a way to lose and manage weight in the early 20th century.
So is calorie counting a helpful way to identify and manage your fuelling for training and racing as an athlete? Here are some thoughts:
Just as in training if you focus on one metric it may not give you the whole story so too with calorie counting. Feeding your body the right nutrients in the right amounts is very important for health and performance - otherwise you could live off soda (high sugar carbonated drinks).
Many people now are promoting eating nutrient dense foods which is a good way to fuel your body both in the short and long term as it will support your immune system and help you recover from training. This means not only considering the calorific content but the nutrients you are getting from the foods you eat.
There are some studies that show there are links emerging between people using calorie counting applications and disordered eating (Romano KA, Swanbrow Becker MA, Colgary CD, Magnuson A., "Helpful or harmful? The comparative value of self-weighing and calorie counting versus intuitive eating on the eating disorder symptomology of college students." Eat Weight Disord. 2018 Dec;23(6):841-848. doi: 10.1007/s40519-018-0562-6. Epub 2018 Aug 28. PMID: 30155857.)
Given the growing prevalence of RED-S (Relative Energy Deficiency in Sport) and the higher prevalence of disordered eating amongst endurance athletes using applications for calorie counting should probably be approached with caution.
Our energy needs will change day to day depending on:
If you are hoping to lose weight going into some calorie deficit may help you do this; if you are hoping to make fitness gains you may be compromising the efficacy of your sessions by not getting in the nutrients and energy you need.
For athletes looking to improve their body composition it is advisable to do this in the off season when you are not also trying to reach other fitness goals.
Most training computers will give you an estimate of calories burned during a workout. If the device is personal to you this will be based on your height and weight and possibly some other factors.
However, compare different devices and you may not get the same number. There are a number of factors that can affect how much energy you need and use for a session (Shcherbina, Anna, C. Mikael Mattsson, Daryl Waggott, Heidi Salisbury, Jeffrey W. Christle, Trevor Hastie, Matthew T. Wheeler, and Euan A. Ashley. 2017. "Accuracy in Wrist-Worn, Sensor-Based Measurements of Heart Rate and Energy Expenditure in a Diverse Cohort" Journal of Personalized Medicine 7, no. 2: 3. https://doi.org/10.3390/jpm7020003).
Being able to assess your own hunger levels during and after a session and eat accordingly may be a better and safer option. In fact there is evidence to suggest that intuitive eating can work well as a way of managing your body's day to day needs and improving your relationship with food.
Most applications for training in endurance sports are designed with endurance training in mind; they are not so good at assessing the 'strain' cause by weight training. If the calories burned are assessed using heart rate your heart rate might not go up very much at all during a weight training session as the load may be high but for a very short period so your heart rate does not have time to respond. 6 deadlifts at 70% of your max 1 rep weight will not take long but it will be a big strain on your muscles and create some muscle fibre break down.
Similar to my point above, your heart rate does not have time to respond in short efforts of 30s to 3 minutes. Calculations based on Functional Threshold Power/Pace could potentially be better.
Doing a long technical descent on a mountain bike or when out mountain running can be very taxing on various muscle groups, but your heart rate is likely to drop. The calories burned is likely to be less accurate than on a consistent flat road at a consistent pace/speed.
Adapting to altitude can also mean that your body needs more fuel to do workouts. As breathing rate increases and blood and muscle pH decrease, the body starts to favour carbohydrate as an energy source BMR has been seen to increase even in trained athletes (Woods AL, Sharma AP, Garvican-Lewis LA, Saunders PU, Rice AJ, Thompson KG. Four Weeks of Classical Altitude Training Increases Resting Metabolic Rate in Highly Trained Middle-Distance Runners. Int J Sport Nutr Exerc Metab. 2017 Feb;27(1):83-90. doi: 10.1123/ijsnem.2016-0116. Epub 2016 Aug 24. PMID: 27459673).
Genetics
Some people genetically have a higher Base Metabolic Rate than others; this is often due to the amount of thyroxin a person produces, even within normal ranges in healthy individuals some people will produce more and some less than others.
As with most things, nutrition, fuelling and energy expenditure is perhaps not the exact, simple science we once thought it was. There are, however some good rules of thumb:
Within context, it can be helpful for some people to track calories as well as other nutrients periodically for a short amount of time to check that they are eating well for the amount of training they are doing. If you have a history of disordered eating or feel a bit overwhelmed by it all, a good way to do this might be to enlist an expert who can give you feedback on your nutrition and how to improve it. This does require some effort on your part to communicate your daily intake, but may eliminate the need for you to see and worry about numbers if that concerns you.
If you have particular problems with weight (being under or over) measuring portions so you get an idea of what 1 portion should look like on your plate can also help in the short term until you get an idea of how much is enough for you.
If you would like some more in depth guidance on nutrition you can book an appointment with us; there is currently a special offer until the end of August 2024 using the link NUTRITION30.