I understand the benefits of a heat block can be a higher sweat rate (faster onset of sweating) and increased blood volume.
have a very high sweat rate already based on testing (1.8-2L an hour) and tbh don’t want it any higher - it’s already hard to stay on top of replacement as it is - so blood volume would be the main benefit for me I suppose.
I also live in FL so am consistently faced with some brutal conditions (80-90 degree temps and a dew point of 75+).
My initial thinking was that simply training in this environment would give me some good heat adaptations without having to do specific work, but my friend recently let me borrow his core sensor device and I was surprised to see that even when training outside in the heat and arriving home absolutely soaked in sweat and down 8 pounds of fluid the core device rarely showed that I was actually training in a heat zone which I found a bit confusing. I was reading around an opinions seem a bit mixed on this device but curious if others have had similar experiences…
I’ve been using a Core Sensor on and off, and I’ve found it can be a bit finicky. Did you have an HRM paired to it (via the app)? If you don’t have an HRM paired, the core temp data will likely be way off and thus useless. I also agree with the reply above that you should do a heat ramp test, as Core instructs, to calibrate your core temp zones.
Also I’m not an expert, but the output can be difficult to interpret. Their “zones” are based solely on core temperature, but from my limited understanding, “heat training” is more about the differential between core temperature and skin temperature. As an example, it could be freezing outside, but if you’re working hard enough, your core temperature could be in a “heat zone” while your skin temperature will be low, and therefore you will not be getting any “heat adaptations.” So I believe one should focus more on the core/skin differential, rather than pure “time in zone.” I believe the differential is the primary driver in their "Heat Strain Index’’ and “Heat Strain Load.”
I had a Core sensor, was one of the test groups before it launched. I live in Tucson and the year I got it, it was an unusually hot summer. We finished multiple 5-6h rides at 105-106F temps. Ultimately I stopped using it because 1. It didn’t tell me anything I didn’t already know 2. the data from it was sporadic at best. It would often glib out for 20-60min. 3. The heat ramp tests I tried to do always lost data.
You are making adaptations by training in the heat and your understanding of the adaptations are pretty spot on. Also the increased plasma volume will initially decrease the total % of RBC which then tells your body to ramp of production of RBCs.
If you went to MI or the PNW and raced, even during a heat wave you would LOL at everyone complaining about how hot it is.