Walking like this consumes 20% to 60% more energy!

Compiled by: Gong Zixin

Which do you prefer, long continuous exercise or short interval exercise?

A team of pathophysiologists from the University of Milan has found that short bouts of exercise (10 to 30 seconds) are more effective than continuous exercise for the same distance.
The results of the study were published in the Proceedings of the Royal Society B.

Image source: The Royal Society Publishing

The energy requirements of exercise in a metabolically steady state have been extensively studied. The research team noted that existing reported energy expenditures tend to reflect activities performed in a metabolically steady state, a state that is only established after an activity has been performed for a period of time. However, most exercise bouts are short and consist of a few consecutive steps. Quantifying energy expenditure is critical to revealing how the energy budget is allocated and gait, speed, and path are selected to optimize metabolic cost or trade off metabolic cost with time, muscle activity, and stability.

So the researchers wanted to know if people would expend energy differently if they did short, start-stop exercises multiple times. To find out, the researchers recruited 10 volunteers and asked them to walk on a treadmill or climb a flight of stairs for varying lengths of time, from 10 seconds to four minutes. While exercising, the volunteers were asked to wear masks to measure oxygen intake, a way to measure energy expenditure.

Experimental setup and analysis of oxygen uptake data

In this study, the research team tested whether the duration of exercise affects the oxygen and metabolic cost of walking in humans. The results showed that multiple short bursts of repeated "start-stop" exercise consumed more oxygen than steady, longer-lasting activity over the same distance. Further tests showed that multiple short bursts of exercise increased energy expenditure by 20% to 60% compared to one long exercise.

The researchers explain that the reason for this is that the body uses more energy when preparing for an activity (warming up) and getting into a good state of motion than when reaching a steady state, just as a car uses more gas when accelerating from idling than later.

For humans, incorporating short bouts of walking into daily life is also a cornerstone for promoting physical activity and health. Exercise programs based on short walking distances are used in the treatment and rehabilitation of several clinical conditions, including obesity and stroke, and understanding the costs of short bouts of exercise is crucial for tailoring training, especially for people with low aerobic fitness who need more time to reach a metabolic steady state.

The research team recommends that people who want to get more benefits from their daily exercise should perform multiple short exercise sessions rather than long sessions at a steady pace.