A good quick-and-dirty test uses the humble push-up. Periodically (every two or three days) just do as many push-ups as you can—this will likely involve moderate discomfort on the last few—and track the number you do over time. While there is some day to day variance, I think this is a pretty good rough proxy for general fitness and a few weeks of data would give you decent tracking of the trend, unless you are already in such good shape that marginal improvements are hard to discern.
Maxing out on push-ups every couple of days is good fitness advice, but using them as a proxy for general fitness is problematic: it’s very easy to exchange form for higher repetitions when doing push-ups, especially if you’re not working with a trainer or gym buddy. There’s a built-in incentive to do this if you’re using them to measure your fitness, and it’s easy to do it unconsciously. Falling into this trap gives you a false indication of progress, and also limits the quality of the exercise: you need a full range of motion to engage all the muscle groups involved.
The only way to keep yourself from doing so is to consciously prioritize form: your back should be straight, your body should just brush the floor at the bottom of its motion (chest and groin more or less simultaneously), and you should straighten your arms as far as they’ll go without locking your elbows at the top. End the set once you can no longer do this.
A good quick-and-dirty test uses the humble push-up. Periodically (every two or three days) just do as many push-ups as you can—this will likely involve moderate discomfort on the last few—and track the number you do over time. While there is some day to day variance, I think this is a pretty good rough proxy for general fitness and a few weeks of data would give you decent tracking of the trend, unless you are already in such good shape that marginal improvements are hard to discern.
Maxing out on push-ups every couple of days is good fitness advice, but using them as a proxy for general fitness is problematic: it’s very easy to exchange form for higher repetitions when doing push-ups, especially if you’re not working with a trainer or gym buddy. There’s a built-in incentive to do this if you’re using them to measure your fitness, and it’s easy to do it unconsciously. Falling into this trap gives you a false indication of progress, and also limits the quality of the exercise: you need a full range of motion to engage all the muscle groups involved.
The only way to keep yourself from doing so is to consciously prioritize form: your back should be straight, your body should just brush the floor at the bottom of its motion (chest and groin more or less simultaneously), and you should straighten your arms as far as they’ll go without locking your elbows at the top. End the set once you can no longer do this.