Is doing 100 push-ups enough to build muscle?

How many reps do you have to do for a workout or exercise to be effective? This is a relatively common question I receive as a calisthenics coach. Questions like these are great, but they do very little to help you build the muscle you want. There are better ways to assess the effectiveness of your workout program than trying to figure out how much work you should do. 

This is because all static answers will provide little value in helping you understand how to go about reaching your goals. No matter what answer you come up with, it will steer you wrong sooner or later. It doesn’t matter if I tell you to do 50, 100, or even 1,000 push-ups daily. Any set number I recommend will probably be the wrong one for you sooner or later. Assessing the effectiveness of your training on how much work you do is like having your car's GPS tell you to drive straight ahead, and that's the only instructions your gps ever tells you. Driving straight ahead may be the correct route at the moment, but sooner or later you’ll need to follow some additional instructions ot get where you want to go.

The same thing applies to building an effective workout. Any sort of advice or instructions you receive will only bring you so far. Continuing to follow any sort of unchanging recommendation can even lead you off course if you follow it long enough. 100 push-ups could be moving you forward for a short term, but eventually you will  plateau and you're never going to move beyond the limitations of that “optimal” program. 
In some cases, 100 repetitions could actually be a regression and compromise your results. Your ability to get results does not come from the formula or your routine you follow. Success does not depend on  how many sets and how many reps you do in your workout. The results you want come from the delta, or the difference you create from what you normally do. 

So the question isn’t if doing 100 push-ups is effective but rather what sort of change you’ll experience from adopting the habit of doing 100 push-ups. Will the new habits create a progressive change from what you're doing now, or will it not be much of a change? Or is it even going to be a regressive change and compromise your current level of fitness?

My job as a coach is to help you create a progressive change in each of your workouts. Maybe that will come from doing 100 push-ups, maybe not. You may even be better off not doing classic push-ups at all for a bit and I’ll give you something more effective for your goals. 

But the bottom line is that your success won’t come from chasing an arbitrary metric or cookie-cutter formula. To do so is to train without any real plan or purpose. You’re putting in the work and hoping to find success through chance and random luck. Personally I don’t like to leave my progress to chance, nor do I want that for my clients. I like knowing that what I’m doing is working and that’s why I track workouts and keep a separate workout log for all of my clients. When you know what to do to make progress in each workout, you no longer have to make your workouts a guessing game with metrics like doing 100 push-ups.