Exercise science researchers pinpoint method

It’s a common phenomenon for anyone who trains regularly: two people with similar fitness levels can do the same exercise and get completely different results. It is extremely frustrating for the person who can’t seem to improve, despite trying their best.

A group of exercise science researchers at Brigham Young University know the feeling and have tried to solve the problem. Good news: they think they’ve cracked the code.

The team’s recently published research reveals a more effective way to determine the intensity at which each person should exercise to achieve the best results. A study that appears in Journal of Applied Physiology describes a new system for creating not just personalized workouts, but “prescribed” workouts that deliver results regardless of an individual’s current health.

“One day we may be able to prescribe exercise as medicine,” said Jayson Gifford, a BYU professor of exercise science and lead author of the study. “To prescribe medication, you need to have predictable results for each dose of medication. We have discovered that exactly the same applies to exercise.”

The research explains that when exercise is personally prescribed based on what is called “critical power,” the results show greater improvement in endurance and greater long-term benefits for the individual. The authors define critical power as the highest level of our comfort zone. “It’s the level where we can perform for a long period of time before things start to get uncomfortable,” said study lead author Jessica Collins, a former BYU graduate student.

Here’s how it works: Let’s say two friends have a similar maximum heart rate. Previous understanding of the exercise would suggest that if they run together at the same speed, they should have very similar experiences. However, it turns out that when these two friends are running at 6 mph, the exercise is easy for one, but difficult for the other. These distinctive experiences at the same speed and maximum heart rate percentage are due to 6 mph being below one friend’s critical power, but above the other’s critical power.

When exercise is below a person’s critical power, their body can compensate for the energy challenge and achieve a comfortable and controlled homeostasis. However, when exercise is above one’s critical power, your body cannot fully compensate for the energy demand, resulting in exhaustion.

Traditionally, individualized exercise has been recommended based on a fixed percentage of the maximum rate of oxygen consumption (VO2 Max) or maximum heart rate. Collins and Gifford said that using “critical power” is a better way to prescribe exercise because it not only accurately serves athletes and those who are in good shape, but it also serves older people or those with a poorer training style. more sedentary life.

“This kind of research helps all kinds of people, no matter how active they are right now,” Collins said.

For the study, Collins, Gifford and co-authors recruited 22 participants between the ages of 18 and 35 who were healthy but had low fitness levels. Participants underwent eight weeks of supervised physical training in which they were randomly assigned to either high-intensity cycling training or continuous moderate-intensity cycling training. Exercises were traditionally prescribed based on a person’s maximum heart rate or VO2 max.

The researchers found that prescribing exercises based on VO2 Max as a benchmark leads to alarming variability in results. There were participants who benefited significantly from the training period and others who did not, despite the fact that the training was personalized for them. They compared this to each individual’s critical power and found that it accounted for 60% of the variability in their findings. If the exercises had been prescribed taking critical power versus heart rate as a reference, the results would have varied less, so the workouts would have been more effective and beneficial for each participant.

“One of the main reasons people don’t exercise as much as they should is because they’ve tried something in the past and it didn’t work out the way they hoped it would,” Collins said. “The great thing about basing exercises on critical power is that we can almost always guarantee the result, which allows us to help people achieve their fitness goals.”

To calculate a person’s critical power, the researchers had participants complete various exercise distances (ie, running, cycling) as fast as they could. They then took average speed and plugged that data into a proprietary formula that determines the relationship between exercise distance and exercise time to produce a critical power number. They found that a person’s critical power can be increased substantially with physical training, making things that used to be difficult less challenging, less uncomfortable, and less fatiguing.

“Exercise is so good for you that you will see some kind of benefit no matter what you do,” Gifford said. “This research simply informs people that they can more fully optimize their exercise so that they get more out of it. We are excited for when it will be more accessible for people to know their personal critical power in the near future.”

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