Comment by MyHonestOpinon
18 hours ago
I try to do 180 minutes a week of cardio. Mostly Zone 2. Biking, elliptical, tKD. But once in a while my legs feel too tired, so I complete my weekly minutes going to the steam room. It makes sense to me since it raises your heart rate.
Also, my samsung watch can measure stress (whatever it means). It always shows the very, very minimal stress for me. The only time that I have been stressed was the day that I spent a bit too much on the steam room.
FWIW, most of the studies on improvements in blood plasma volume from passive heat are usually done on saunas with temperatures > 150 degrees F (60 C). Steam rooms usually only get up to 120F (~49C) even though the humidity probably makes it feel warmer.
FWIW you should probably be doing some max intensity, or at least high intensity cardio.
Zone 2 is great but the best health outcomes are from people who do high intensity exercise interspersed with zone 2 exercise.
This is contested by a significant number of contemporary running coaches (see, for example "Training for Uphill Athletes" by Steve Johnson or any of the life work of Phil Maffetone.
HIIT is quite effective at something; it's not clear that it is effective at all possible exercise goals (including, but not limited to, endurance running).
Johnson in particular says that unless you've already narrowed the gap between your "first" and "second" (anaerobic) threshold to 5%, HIIT really doesn't make much sense because you're "aerobically challenged" and need to work on that first, which he believes (with significant evidence) is best done almost entirely in zone 2.
He also notes that someone like Eliud Kipchoge can spend 2 hours running 4:30 min/mile pace, so that is clearly within his aerobic range, but that Kipchoge would never and should never spend much time training at that pace because of the load it would put on his system. So the zones that are used for training purposes depend significantly on the current fitness level of the athlete.
I have used HIIT effectively to get myself out of certain fitness/training "ruts", but I think that the zone 2 folks have somevery cogent and coherent observations and advice.
I think one issue I have with Zone 2 proponents is that it makes sense that if you can do a lot more stuff at Zone 2 than you can at less. For most endurance athletes, the volume of running beats everything else in terms of efficacy. However, most of us don't have unlimited time.
For example, if I do a week of 3x30 minute swssions at Zone 2, my fitness is going to plummet. But if I do one at Zone 2, one at tempo, and one set of intervals, I'm at least maintaining fitness.
Would 5 hours at zone 2 be better? Absolutely. But I dont always have the time.
Only z2 is for complete noobs. UA actually recommends 80/20 split between z1 and upper z3