After a bad week, you may hit the gym to blow off some steam. Once your body is pumping with “feel-good” endorphins, you head out into the world a new and happier man.
Too much mental stress, though, can take the edge off your workout. Researchers from the University of Texas put 31 undergraduate students through a heavy-resistance exercise protocol. Students who were more stressed had slower muscle recovery than their laid-back classmates.
The study, published in Medicine & Science in Sports & Exercise, involved a leg-press test: six sets at 80 to 100 percent of 10-rep-max. Researchers tested the students’ maximum isometric force—muscle strength—directly before and after the sets, as well as 20, 40 and 60 minutes later.
Students with higher stress scores took longer to recover their maximum strength. This was true even after taking into account the students’ fitness, workload and training experience. Energy levels, fatigue and soreness, however, were all unaffected by mental stress.
This lines up with previous research that has found many negative effects of stress, including an increased chance of illness or sport-related injuries, slower recovery after illness or surgery, and lesser strength adaptations after workouts.
Exercise is still a good way to relieve stress, so don’t hang up your running shoes just yet. It’s a good idea, though, to find other ways to deal with mental stress. You should also be keep an eye on your mental stress, and adapt your workout if your levels are off the charts.