I wouldn't recommend focusing on push-ups, they are counterproductive if you have the typical "computer posture" with hunched/forward shoulders. Chin-ups, rows, and similar are likely to be a better idea.
And in my opinion are entirely missing the point because they take more pre-planning and effort. Even if only a little.
The problem people are trying to solve is "how do I go from nothing to exercising even a little?" The problem you are helping them solve is "how do I get more/ the most out of my workout?"
It's a serious pet-peeve of mine. I know you mention it with good intentions, but people often try to help others by telling them their personal favourite item, vs helping them solve their problem.
People do similar with programming languages. For a one off project or getting started sometimes a shitty language is the best way to help someone for their specific problem.
1. http://exrx.net/Kinesiology/Posture.html
2. https://www.theptdc.com/2014/07/upper-crossed-syndrome/
As for programming languages, I've sent "pull requests" for AutoHotKey programs via Reddit PM before. If it's the right tool (or a decent one) for the job...