Thanks to fitness-tracking devices, the activity levels of the 28 people in the study were easy to monitor.
Before the study, the young adults walked an average of 10,000 steps each day, for a total of about 161 minutes. During the 14-day trial, they walked only about 1,500 steps daily, for a total of 36 minutes.
They made no changes to their diet. Food consumption was consistent before and during the study.
Researchers call the physical fitness changes “small but significant.” In addition to less muscle mass and more body fat, participants’ cardio-respiratory fitness levels also declined sharply. And they were unable to run for as long or at the same intensity as they had before the study.
“The [study] results emphasize the importance of remaining physically active, and highlight the dangerous consequences of continuous sedentary behavior,” researchers concluded.