Should athletes use calorie burn calculations on a smart watch? – Triathlete

Your smartwatch is truly as smart as its name suggests. It records your laps in the pool. It helps you monitor your rhythm on that morning commute. Prevents you from running in Zone 3 on recovery day.

But your can Smart watch Also measure how many calories you burn during each training session? Several studies suggest that it may not be the best option for determining how many calories you need after exercise.

The good news is that there are other ways to count the calories you burn. According to Taryn Richardson, advanced sports nutritionist and founder Approved by a nutritionist and Triathlon Nutrition Academyit’s entirely possible to refuel properly after a workout without being certain of exactly how many calories you’ve burned by focusing more on the most beneficial macronutrients to consume and focusing less on your smartwatch’s calorie estimate, which can be somewhat inaccurate.

What smart watches go wrong

“Smart watches estimate calorie burn using your heart rate plus motion sensors and your personal data, which is fed through a proprietary algorithm. But heart rate alone is not a reliable indicator of energy expenditure, which is often expressed in calories burned,” says Richardson, explaining that smart watches cannot accurately measure the variables required to accurately determine true calorie burn: actual metabolic rate or body composition.

“Let’s take two athletes of the same age, gender and weight,” says Richardson. “The calories they burn running side-by-side, at the same pace, could be very different if one athlete has more body fat and the other has less muscle mass. But their two watches will show almost identical numbers because the algorithm doesn’t take into account differences in body composition.”

Research has shown that even the most high-tech smartwatches fail when it comes to measuring calories burned. 2017 study who tested seven commercially available wrist-worn devices revealed that the least accurate device was off by an alarming 92.6% in calorie counts. The most accurate clock was 27.4% behind.

According to A 2020 validation study Which tested four Popular wearable devices on the wrist,Power consumption was not measured with an error less than 32%. And a 2022 systematic review According to the accuracy of 72 wrist wearable devices, it reported that power consumption error rates exceeded 30% across all major brands.

Given these errors, you may end up overfueling if your watch overestimates your calorie burn. Conversely, your smartwatch can underestimate (especially if you’re consuming fuel during Your workout), preparing you to shine in the next session. Fortunately, there are other ways to track how many calories you’ve burned.

Alternatives to measuring calories burned

Consider tracking your calories using Total daily energy expenditure TDEE calculator. Look for a TDEE app that uses the Katch-McArdle formula, which takes body fat percentage into account, recording calorie intake and body weight daily.

After a few weeks of continually entering your individual data, the calculator uses it to estimate how many calories your body burns each day. Keep in mind that although TDEE apps and online calculators are more reliable than smart watches, they are still 10 to 20% inaccurate, so limiting your calorie intake solely to generated numbers can result in slight under- or over-eating.

Surprisingly, your bike Energy meter It may be one of the most useful tools for tracking calories burned. Although it does not directly measure calorie burn, the power meter measures external work.

“From that, you can estimate your energy cost with reasonable accuracy. But again, applying that number is not ‘eat 1,500 calories again’ because you’re estimating that you burned 1,500 calories. ‘This was a high-demand session, so I need to fuel to recover accordingly,’ says Richardson, adding that the most underrated tool is your body. ‘Hunger, energy levels, quality of training, sleep, performance trends, and body composition over time are real biological signals that tell you whether you’re Fuel appropriately. “It’s free, it’s customizable, and it doesn’t require a charging cable.”

The best post-workout macronutrients

Instead of asking, “What’s the best way to calculate how many calories you burned while working out?” To replace that exact amount, Richardson suggests asking: “How can I refuel from the session I just had.” and Fuel for the next one?”

“If you’re training again that day, you have a tight window to refuel, and you need macronutrients quickly. If your next session is 24 hours later, you can get them through regular meals,” says Richardson. the Primary macronutrients – Carbohydrates, proteins and fats – essential for your body to produce energy and support daily functions.

Here’s what Richardson suggests you eat within 60 to 90 minutes of finishing your workout:

1. Carbohydrates to replace the fuel you just burned.

If you are training again that day, consume 1 to 1.2 grams of carbohydrates per kilogram of body weight every hour for a few hours. If you exercise for the day, eat a regular meal that contains the carbohydrates you need. Choose real food when possible, and only choose liquid carbohydrates if your intestines stop working after a session and you can’t digest solid food.

2. Protein to rebuild muscle.

Aim for 20 to 40 grams of high-quality protein. Although whey or Protein shake They’ll do the trick if you’re traveling: Whole foods are ideal because they equate to slower digestion, extra nutrients, and a feeling of fullness that powder doesn’t provide.

3. Fruits and vegetables to fuel recovery at the cellular level.

Although macro goals are a priority, athletes also have higher micronutrient needs, which can be met through fruits and vegetables. Improve blood flow and support immunity and gut health by eating a variety of colorful produce.

Here’s one example of a post-workout meal that properly contains macro- and micronutrients: 3 to 6 ounces of cooked chicken breast, rice (1 cup = 45 grams of carbs), and a side of steamed vegetables. But where is the fat? If you get your carbs and protein right, you’ll get the fat you need.

Learning to refuel depends on practice, not your smart watch

Since smartwatches do not yet provide accurate calorie counting, they should not influence fueling decisions. In this regard, calories should also not be tracked.

“Athletes who are recovering are usually the ones asking what each meal does for their health and performance,” Richardson says. “Instead of tracking calories, track your training load, and then eat to support it. That’s the whole game.”