We all know exercise is good for you and most of us probably have great intentions of doing more than we currently do. More often than not, however, the idea of exercising at the end of stressful day is just not appealing. We would far rather curl up on the couch and watch TV than pull on exercise gear and venture outside. Yet in the long run exercise may help to build up resilience against stress.
Studies have shown that people who are more physically active are less prone to stress [1]. Research has even shown that children who are physically active have a less extreme biological reaction to stress compared to their peers who are not physically active [2].
But why is exercise good for stress? It certainly doesn’t feel like a stress relieving activity at times, particularly when your breath is ragged, your muscles hurt and the air outside is cold. We know that exercise can be good for stress but research is only just starting to find out why. In a recent study researchers in the Karolinska Institute in Sweden noted that a protein called PGC-1alpha1 builds up in the muscle when people exercise [3]. This protein can also clear out enzymes that travel from the blood to the brain and are associated with stress-induced depression. They therefore wondered if this protein may be part of the answer as to why exercise reduces stress. They took two groups of mice, one group with a high level of this protein in their muscles and one normal group. They then stressed them out by exposing them to noise and flashing lights, something that creates stress-induced depression in the animals. They found that the group with the high levels of PGC-1alpha1 protein did not become depressed with the added stress while the normal mice did. The exercise-related protein seemed to protect the mice from the effects of stress.
Of course more research needs to be done in humans to really understand the effects but it is one more step towards understanding how exercise affects stress and, maybe, one further step to getting us out the door to exercise at the end of a stressful day.
1. Schnohr, P., et al., Stress and life dissatisfaction are inversely associated with jogging and other types of physical activity in leisure time—The Copenhagen City Heart Study. Scandinavian journal of medicine & science in sports, 2005. 15(2): p. 107-112.
2. Martikainen, S., et al., Higher levels of physical activity are associated with lower hypothalamic-pituitary-adrenocortical axis reactivity to psychosocial stress in children. The Journal of Clinical Endocrinology & Metabolism, 2013. 98(4): p. E619-E627.
3. Agudelo, L.Z., et al., Skeletal muscle PGC-1α1 modulates kynurenine metabolism and mediates resilience to stress-induced depression. Cell, 2014. 159(1): p. 33-45.