Developing both muscle fibres for endurance and explosiveness

Question

I'm an avid runner but I also train BJJ and so I want to have good endurance and some explosive power without being bulky. Recently, my strength training has just consisted of bodyweight exercises (pull-ups, push-ups, planches etc.). I'm intending on also getting a 20kg kettlebell soon as well.

As I understand it, slow twitch muscle fibers are the ones working when I'm doing an exercise that requires endurance and fast twitch muscle fibers are the ones working when I'm doing an exercise that requires explosive power.

1. When I'm doing push-ups (or pull-ups), are they working my slow-twitch or fast-twitch?

2. If they use slow-twitch, I'm guessing plyometric/explosive/clap push-ups stimulate fast-twitch so should I do both to get power and endurance?

3. Or does it depend on the rep range? Because for example, if I can do 20 explosive push-ups, will I no longer be able to develop my fast-twitch muscle fibres because the rep range is too high?

4. Also, I read that slow twitch muscles fibers aren't able to grow as much as fast-twitch muscles. When you gain endurance, do the slow twitch just get more efficient? Whereas fast twitch get better by getting bigger?

Answer 1

Fast-twitch muscles are used and developed by moving fast. Regular push-ups can be done a little fast, but basically you want to do clapping or plyometric push-ups to really develop explosiveness.

If you start doing 20 reps of push-ups, no matter what kind, those reps aren't going to be particularly explosive. If they are, they won't be challenging enough to really produce an optimal training stimulus.

Muscle endurance is different from activity-specific endurance. They're related, but your ability to roll longer and harder at BJJ is not the same as your ability to do 50 push-ups in a row.

What You Should Do

You already run and do BJJ, so there's absolutely no reason to do more endurance work. To get more endurance and explosiveness you need to work on your weakness, which is probably strength and power. The Olympic lifts and supporting programming would be a fantastic idea.

So: you should learn the power clean, and see if you have the mobility to snatch. You should get access to an Olympic barbell that spins well, as well as to bumper plates and a lifting platform. You should deadlift and squat and do some push presses after developing some basic overhead strength with regular presses. Deadlifting is well-recommended for both running and general strength, and squats are one of the best ways to rapidly develop strength. The fast lifts, the clean and snatch, develop power better than any other exercise. Push presses are similarly excellent for training upper-body explosiveness.

A 20kg kettlebell will be okay for this purpose, but not really ideal. It won't be heavy enough to do squats or deadlifts that are really challenging. To get the most out of it (if you intend to stick with the kettlebell and not get a barbell), focus on cleans, snatches, presses and push presses, Turkish get-ups, and develop a pistol squat that's so good you can eventually add the kettlebell.