Researcher: Don't let fitness trackers take over your workouts

Watches and other activity trackers provide an abundance of data about how exercise affects your body. A researcher shares five tips to ensure that technology helps rather than hinders your progress.

Over time, the way we work out has changed dramatically – or at least the way we measure our training.

(Photo: Blocks Fletcher / Unsplash)

Walter Norman Wehus COMMUNICATIONS ADVISER

Presented by: University of Agder

Published 16 March 2025 - 00:00

“When I was 12, my gym teacher had two technical aids: a whistle and a stopwatch. Today, we have sensors that measure everything from heart rate to oxygen uptake, how well we sleep, and how rested we are,” says Stephen Seiler.

He is a professor at the University of Agder. Seiler has extensive experience with how to train most effectively and has worked with Olympiatoppen, an organisation that develops Norwegian elite athletes, for over a decade.

During this time, the way we train has changed radically. Or at least how we measure our training sessions.

“Before, athletes struggled to get enough data to make good decisions. Now we have so much data that it can be overwhelming. And much of it isn't useful,” says Seiler.

He has five pieces of advice for those who use new technology when exercising. And at the end, he shares a tip about something almost everyone does wrong, which will help you train smarter than most people.

5 tips for smart gadgets

1. Ensure the measurements are accurate

No decision is better than the data it is based on.

“If your heart rate monitor gives you crazy numbers pointing in all directions, it's likely because the wrist isn't the best place for such measurements,” says Seiler.

He emphasises that consumer technology is not always accurate. That's why most athletes still use old-school chest straps for heart rate measurement.

2. Don't base your training on a single measurement

Heart rate measurements can be tricky to understand. When you're tired, your heart rate might be higher than normal. But it could also be lower than normal. This means heart rate alone is not enough to determine your fitness level.

“Pay attention to how you feel and whether you're running as fast as you usually do. Along with your heart rate measurement, this can give you a better picture of your daily condition,” says Seiler.

Stephen Seiler is a professor in the Department of Sport Science and Physical Education at the University of Agder.

3. Don't obsess over measurements

Have you ever considered skipping your workout because you forgot your heart rate monitor at home? Many can relate to the feeling that what isn't measured doesn't count.

“If I ask someone how their training was, and they need to check the numbers on their phone first, they have a problem,” says Seiler.

If you become obsessed with numbers and measurements, you may end up feeling stressed. Technology should be a tool, not define your training experience, Seiler reminds us.

4. Don't trust the estimates

Smart gadgets can give us a lot of numbers, but they don't actually measure everything they claim to. This might be disappointing for those who have invested in advanced fitness watches.

“The heart rate monitor measures one thing only – heart rate. So when it tells you how well you sleep, how many calories you burn, your rest and recovery status, it's just nonsense. It's guessing. It makes some calculations and spits out numbers,” says Seiler.

5. Calibrate your brain, don't replace it

“The elite athletes I work with know how hard they work. They have incredibly well-calibrated brains. You should too. Don't stop thinking just because a watch says it can do it for you,” says Seiler.

How to train smarter

We promised you a tip on what almost everyone does wrong – something that will help you train smarter than most. Are you ready? It's simply about not training so hard.

When Seiler explains this, he talks about 'training buckets' in different colours.

In the green bucket, you'll find low-intensity workouts. Here, you can chat with a training buddy or watch the butterflies along the road. When you get home after training, you're probably ready for some food. Most of your training sessions should be like this.

In the yellow and red buckets, you'll find the harder workouts. These involve higher intensity, like interval training and hill runs. Such sessions are an important part of training, but you can't do them every day.

“The most common mistake is to go out every day and pick up workouts from the yellow bucket. You train quite hard for 45 minutes and feel pretty good when you get home. You feel like you've accomplished something. But doing the same thing every day is a recipe for stagnation and boredom,” says Seiler.

Instead, he recommends using three steps to build good training habits:

First, establish a regular training routine.
Then, increase the duration of your workout.
Finally, add some sessions with higher intensity.

“You shouldn't train hard every time you exercise. Most of your workouts should be light or moderately hard, with some intense sessions in between,” says Seiler.

It's all about variety. And, importantly, doing it over time.

“When an athlete ends up on the podium, it's not because of the hard interval session they did two weeks ago. It's about them having been healthy for the past six months and able to train over time. This is equally true for exercisers,” says Seiler.