CORE Heat Suit

Hi!

I started using the CORE Suit for heat training this summer, I previously just used more clothes (arm/leg warmers, buff and vest) when I did heat training, which I have done since 2020.

With clothes I always did a 5 min threshold effort in the beginning to boost the core temp and make it rise quicker. Now I don´t.

The core temp normally rises to about 38,6-39,0 C in one hour in zone 2 (210-230w) with clothes and the core graph looks almost identical with the suit as with the clothes, so I was thinking “what´s the point with the suit if I gain the same core temp with arm- and legwarmers?”. But I kept on using the suit.

There are other differences than core temp.

Skin temp rises much more since the suit isolates the heat, and it stays high, so the ratio between skin and core temp are low (about 1,5-2 C) compared to when the heat evaporate. That rises RPE significally during the whole hour as well as getting a steady drift in HR which I didn’t get before. See difference in the graphs below.

RPE is about 20% higher with the suit on same power output. Not in the beginning but as soon as core temp starts rising.

This is one of my 1hr rides with arm/legwarmers, buff and vest. No HR drift even tho Core rises and with a 5min effort in the beginning.

This is the 1hr ride with the suit. Almost identical rise in core temp but much more HR drift. (the two drops in HR is two small breaks with no pedaling).

I’m thinking the rise of RPE and HR is based on the very small difference of skin and core temp when I’m training with the suit.

Does anyone else have the same experience, or any other ideas why the difference in HR and RPE is so big?

Is it worth to keep train in the suit even though I get the same core temp rise at lower RPE?

I have some ideas but would love to discuss with others.

/Erik, coach at Toppfysik and swedish mountainbiker