Earlier in life, if something was wrong with one part of my body, I just assumed that I was out of commission. As I aged (now 66), I had to let go of that luxury! Something somewhere always seems to be malfunctioning. If I let one part of me dictate what the rest of me does, I'd never get anything done.
Do you skip exercising if you didn't sleep well? How about if you have a problem with one of your knees? I used to just punt in those (and other) situations where I wasn't feeling up to prime.
Now I try to keep my routine going, with adjustments if needed to accommodate the misbehaving part of me. For example, occasionally my back develops a pain in it overnight that won't quit when I start moving around. Instead of not exercising at all, I change up the routine to avoid putting stress on the part of my back that hurts.
If your feet start hurting after walking only half the distance you usually trek, it is ok, at least you walked.
If your legs quit on you, lie down or sit up and exercise your torso, neck, head and arms. If putting weight on your knees causes pain, but your legs are just fine otherwise, lie in bed or on the floor and write your name in the air with your toes!
The point here is, even if you have some kind of hurt or injury in one part of your body, there may be ways to keep the other parts moving. Moving is usually good. Of course, as always, you would want to consult your doctor.
When I was younger, nothing bothered me. I could fall asleep quickly and stay asleep all night (even through my spouse's loud snores!). Now it seems that any change in routine or the slightest degree of stress causes me to wake before it is time and fail to fall back asleep.
When I haven't gotten a full 7 or 8 hours of good sleep, I really don't feel like doing anything. However, I've found that it really helps to go ahead and do at least part of my normal exercise routine. I usually even feel better after moving around a bit.
As we age, daily tasks can become more difficult to accomplish and periodic tasks can require longer recuperation periods. If we let those factors stop us, we miss out on the sense of accomplishment from getting the job done as well as the mental and physical stimulation they provide.
One example of a time I had an extended recuperation time from a periodic task involves maintenance of my brick sidewalk. We have bricks, set in sand on top of a bed of gravel and held in place by a thin layer of concrete. The concrete is typically applied by brushing the loose mix on top of the bricks, after cleaning out the spaces (typically about 1/2 inch wide) between them. Once the mix is in place, it is kept wet for a couple of days by applying a fine mist of water every few hours.
I typically get down on hands and knees (with knee pads) to chip out the broken up concrete and any vegetation. This causes stress on my hands and wrists. We have had this sidewalk for 25 years and I have done this task at least 10 times over those years. It never bothered me until last year. After finishing the work, my wrists and hands were sore for several months before they recuperated!
Since that time, I have adjusted my routine to start slow and do a bit each day, instead of hitting it hard and fast. That seems to work just fine without any extended period of recuperation required. I do this with most daily tasks (even housework) as well as those periodic ones.
Just as we had to adjust our activities to growing bodies as young people, now we have to adjust our activities to declining ones as we age. Don't let age stop you, but respect your aging body!
Disclaimer: I am not a doctor or health care provider. You should always consult yours when in doubt.