How do You Calculate TRIMP When Swimming

SIMS Swimming Pool (Photo credit: Wikipedia)

I’ve written about this before.

I went to check my old calculation today at the pool with my trusty old Polar s720i – which, like many old Polars, work in the pool.

I had a few issues with the unit not picking up the HR track all the time but largely it was OK.

5 TRIMPs per 100m

To cut a long story short I said before that 5 TRIMPs per 100m was about right. That was ages ago. Having retried it today I get the same result. A good efficient swimmer not doing a maximal effort might be 1 TRIMP per 25m length. Then again I  set my zones conservatively. So 5 TRIMPs per 100m seems about right.

<Edit> It’s April now and I still have this nagging doubt that 5 is too high. So totally arbitrarily I now use 4. The reason being that I came up with a figure of, let’s say, 80 TRIMPs for whatever the swim length time was. It (80) just seemed higher than an equivalently hard 80-TRIMP run session over a similar period. ie an 80 TRIMP run felt much harder.