The answer varies from person to person and may be different for aerobic versus strength measures.
I’m reminded of a quote from a famous violinist: “If I don’t practice for one day, I can tell. If I don’t practice for two days, my conductor can tell. If I don’t practice for three days, the audience can tell.”
I laid off all exercise for the last three weeks, partly due to a long vacation, partly to see how much my fitness would deteriorate.
Here’s what I found:
- My time for the one-mile run increased from 8 mins and 54 seconds to 9 mins and 30 seconds
- My maximum number of push-ups increased from 32 to 36
- My maximum number of sit-ups increased from 32 to 34
- My maximum number of pull-ups increased from 8 to 9
Strength measures increased, surprisingly. Was it just a good day, or did my muscles need the time off to rest and re-build? Over-training is a real problem for some folks. At 20 minutes of weight-training twice a week, I doubt I was anywhere near what most consider over-training. I don’t fiddle-fart around during my exercise sessions, but I’m not puking either.
So I won’t feel too bad in the future if I take a couple or three weeks off from strength training periodically.
My endurance for running deteriorated significantly. Is it related to the lack of strength training, the lack of treadmill interval work, or both?
Your mileage will vary.