T Nation

Swimming and Fiber Types

Hey guys,

I just started thinking about something that will probably sound pretty stupid to a few of you, but try not to flame me too much if I’m way off base with this.

I noticed that Chad Waterbury thinks that swimming is a good way to build endurance for MMA fighters. I’ve also met a few SEALs who were pretty big guys even though their job probably requires more endurance than overall strength.

I’ve lately stepped up my endurance training using Waterbury’s Hammer Down Endurance program, but have noticed a slight decrease in squatting strength since adding in the 2 mile runs after the circuit. Although I’m doing descent with the circuit (around 23 minutes), my two mile run is just over 15 minutes right now so I’m sure this slow pace has something to do with it.

Anyway, all of this got me thinking about how swimming would affect muscle fiber types compared to running. We all know that developing aerobic endurance through long runs eventually leads to a decrease in strength and speed. Would swimming somehow help develop a high rate of aerobic endurance while preventing a switch of muscle fiber types? I’m sure there would be some strength loss with very long swims but would it be better than running?

I am a very inexperienced swimmer so I don’t even know which muscles get the most work while swimming. But I’m thinking it would take away a lot of the leg work that is involved in running, therefore preventing a loss in explosiveness derived from the hips and thighs.

Again, this all may sound really ignorant to some of you guys with a lot of knowledge, but I was just wondering your opinion.

Thanks a lot and sorry about the long winded post.


Hi Carter,

Swimming actually has one of the lowest metabolic costs of any activity. It makes intuitive sense when you think about it, as your body is suspended in the water so you don’t have to support it. The cold water (assuming it’s cold) also inhibits metabolism a little bit.

So, what’s actually happening is that you’re not placing much demand for adaptation on your muscle. As such, you’ll see less of a shift from IIa towards I.

Oh yeah, and to answer your question, the muscles about the hip and shoulder girdle are most active in swimming. Hip strength is actually the best single indicator of swimming performance (outside of technique).

I don’t know why any combat athlete would want to do “roadwork” anyway, it’s a waste of time. Endurance work on the mat is much more productive. Just ask Lou Thesz.


thanks a lot Buffalokilla!

No prob

i used to be a long distance swimmer…till i got fat and stoned all the time. my endurance was incredible. i use swimming for HIIT now and it seems to work good for me.

Not an ignorant question at all. I am a swimmer (the sprints) and when I am going through an aerobic phase and doing longer yardage I find myself able to progress on heavy lifts like the deadlift and the squat. Longer, slower swimming doesn’t tax my nervous system much, thus I have plenty of reserve left to lift pretty hard.

When I switch to more sprint-oriented swimming, however, the weights are reduced.