What's better?

[Posiview]

Is doing 100 sit ups, press ups, etc, in one go more beneficial than doing 5 X 20 with a few minutes rest between?

Cheers.

[jwinch2]

Is doing 100 sit ups, press ups, etc, in one go more beneficial than doing 5 X 20 with a few minutes rest between?

Cheers.

I would have to say that it will depend in a large part on what you are trying to accomplish. It sounds like you are looking for improvements in local muscular endurance (LME). If I am correct in that, I would probably suggest going with the 5 sets of twenty for a couple of reasons.

First, if you train heavy enough to hit failure at 20 reps versus 100 you are going to be able to use a great deal more loading which will cause you to perform more mechanical work which brings up the second reason.

Putting your muscle in an ischemic condition (one where blood is not being delivered), is the primary stimulus for LME in that it promotes growth of additional blood vessels. If you are using a load that you can actually perform 100 repetitions, you are not going to be exercising at a high enough percentage of your maximal voluntary contraction (MVC) to cause an ischemic condition. It generally takes between 60 - 70% of MVC to create enough pressure to close off the blood vessels which causes ischemia.

I should also mention that IF your goal is LME, then doing the 5 sets with a much shorter rest time, probably between 30 seconds to 1 minute, will be a much greater stimulus for that particular adaptation. It is the build up of metabolic waste products and lack of O2 and nutrient delivery that initiate the cascade of events leading to collateral blood vessel growth.

Feel free to list your specific goals or PM me if you are interested in talking further.

Good luck!

Jason