We can look at this from a pure physiological perspective say: https://dmm.biologists.org/content/9/6/697 but we’re bound to get lost in details. All you need to do is look at the basics – movement is good for you and more importantly being physically strong is better than weakness in fighting all disease.

Even more clearly described:
“Strength makes everything in living easier, this means less burden on your immune system”
Everyone begins losing muscle and strength around 35 years of age. Preserving your strength may be the single most important anti-aging/anti-disease method there is. At the very least it is running neck and neck with nutrition and proper rest.

Furthermore recovering well from stress and disease is far more likely for the strong verses those with weakness. Serious disease like aging is a disease of wasting. Your muscles waste at an accelerated pace when you are sick.
This may be the worst point in recent history to get weak. In part 3 will talk about easy things you can do even while in lockdown.
Be well, be strong,
Andrew and Tierney