Researchers have found an unusual tip for hikers looking to burn more calories: Instead of plodding steadily from start to finish, consider taking rest breaks.
The advice came from a study of volunteers who were put to the test in the laboratory to measure the oxygen and energy demands of short walks versus longer walks.
Tests on participants showed that walking or climbing stairs in bursts of 10 to 30 seconds required 20 to 60% more oxygen, a measure of energy expenditure, than covering the same distance in one continuous session, largely because walking after several sessions is more efficient. minutes in motion.
“When we run shorter distances, we expend more energy and consume more oxygen to cover the same distance,” said Francesco Luciano, a researcher at the University of Milan and first author of the study. “It’s like having a car that uses more fuel in the first few kilometers than later.”
The team launched the study after noticing that many estimates of the energy required for walking were based on data from people exercising in a metabolic steady state. That is when the heart rate is constant and the body’s energy production and consumption are in balance, a condition compared to a car traveling at cruising speed.
To learn more about the energy needs for different walks, the scientists recruited 10 healthy volunteers who were monitored as they exercised on a stair climber and a treadmill. The exercises include three different speeds with periods ranging from 10 seconds to four minutes.
During the exercise sessions, the researchers recorded how much oxygen each person consumed and calculated the metabolic requirements for the different walks. They found that it took more energy to get going and warm up the body at the beginning of each walk than later in the exercise, when the body was already moving and working more efficiently.
“If we start walking, we may incur some fixed costs at the beginning of the fight,” Luciano said. “By analogy, driving a car requires some fuel to start the engine or get the car out of the garage. We found that starting from rest consumes a significant amount of oxygen just to start walking. We incur these costs regardless of whether we then run for 10 or 30 seconds, so it weighs proportionately more for shorter than for longer periods.”
Measurements taken by the participants on the fitness machines also showed that people are less efficient at converting oxygen and energy into effective movement in the initial stages of a walk, but this improves as they get going.
The work strengthens knowledge about the health benefits of short walks and stair climbing, especially for people who are largely sedentary, and may explain the improvements in fitness associated with popular ‘sports snacks’. These involve short bursts of activity that often last no longer than two minutes. The research was published in Proceedings of the Royal Society B.
In addition to the implications for healthy people, the work will also help design rehabilitation programs and exercise advice for people with limited mobility, such as the obese and people who have had a stroke.
“Researchers have typically measured energy requirements during walks of many minutes. However, many people cannot even walk for that long. Think of the elderly or people with walking disorders,” says Luciano.
“If we want to design programs to promote physical activity or exercise for these people, we need to reconsider how to assess and adapt their energy needs. Understanding the energy demands of short walks could help us promote physical activity in a more inclusive way.”