Question: Why do I find it more difficult and tiring when I take my walk on a treadmill?
Answer: Many people, including me, find a treadmill workout more draining than the same activity on a sidewalk or track. In a 2012 experiment, runners were asked to jog on a track while rating how difficult the exercise felt. Then they hopped on treadmills without speed displays and were told to set the machine to a pace that felt the same as what they had just run. Almost all chose a speed that was much slower. On the treadmill, this gentle pace felt as difficult as swifter running on the track.
But scientists are unsure why treadmill exercise feels harder. Most people’s biomechanics are the same, whether they are on a treadmill or the ground, studies show. And where there are differences, the advantage would seem to reside with the machine. Treadmill jogging is less jarring than running on the ground, for instance. A 2014 study shows that we strike the ground with about 200 percent of our body weight while running on the track and only 175 percent of our body weight when we are on a treadmill.
So the most likely explanation for any drudgery associated with treadmill exercise is psychological. Treadmills are indoor machines, and many studies show that people generally prefer outdoor workouts. In various experiments, people have reported experiencing less fatigue, more vitality and greater pleasure after walking outside compared with on an indoor treadmill.
Also, treadmills typically provide a walk to nowhere, which may be demoralizing. In a study published last year, volunteers who set out to walk a course that had no clear finish line felt more fatigued afterward than when they covered the same distance with an obvious finish line ahead on which to focus.
So the lesson may be that, if you can, find a treadmill with a monitor and video programing showing an outdoor walking course with a beginning and, most important, an end.