Back in 1960, US President-elect John F. Kennedy complained Americans were not fit enough and exhorted them to take 50-mile hikes.
His advice was not taken up, and since then, exercise levels throughout Western countries have declined alarmingly.
So much so, that a recent meeting of the American College of Sports Medicine focused on how little exercise we could get away with.
Dozens of presentations came to the same conclusion a few minutes per day of strenuous exercise is enough.
A widely read 2006 study by Martin Gibala, a physiologist at McMaster University in Ontario, found that a three-minute sequence of hard pedalling on a stationary bicycle followed by a rest, repeated five to six times, achieved the same muscle response as 90-120 minutes of continuous pedalling.
Since then, a flurry of studies has shown that a few minutes of strenuous exercise appears to increase aerobic fitness.
However, micro workouts haven’t been shown to improve all areas of fitness yet. Dr Paul Thompson is a cardiologist at Hartford Hospital, Connecticut, and he warned that these studies haven’t shown if short bursts of exercise can reduce disease or increase lifespan. Nor have they indicated if this form of exercise can help with weight loss or muscle gain.