I think the body needs movement to function properly and I love the after effect of any form of exercise where the body feels more alive than before the exercise. Losing the grip is something that I always worry about when I get off track due to life's circumstances, it becomes way harder to get back on track and sometimes, my mind just wants to give up :)
My training regime is mostly running and walking, occasionally, lifting weights.
That's a good mix.
Exactly that happens with me, if I miss it a few days then it's difficult to get back and it takes me long time to get back on track