High humidity strategy = slow down?
About a month ago, the weather shifted from cold to hot and very humid all of a sudden here on the East Coast. Because we normally have a gradual change in weather, this year's sudden change was a stunning demonstration to me of the effects of humidity on HR and pacing. (And I differentiate heat from humidity because it appears the humidity has a much more dramatic impact.) During workouts in this humidity, my HR has increased by 12-20 bpm versus the same pace/power/interval length as workouts earlier this Spring. On longer workouts, this elevated HR has significantly decreased my energy level.
So, is the only way to cope with these effects of humidity to slow down/reduce power? (I drink a TON of fluid during workouts because my "sweat rate" is about 75 oz/hour)
Comments
Fookin' hot is fookin' hot, whether it's 100 and dry or 85 and humid doesn't matter much, in my opinion. Increase heat = decreased power and pace = not as much of a make-me-faster adaptation as cooler temps and higher paces/watts. Therefore, if possible, you should try to separate your go-faster sessions from the heat as much as possible. That likely means very early morning, if you can swing it.
You only need about 3wks of purposely training in the heat to become fully adapted to the heat. Purposely seeking out heat before this 3wk period simply places unwanted stress on your body, decreases training power/paces and doesn't result in the same fitness gains.
Yes, I understand that we are often stuck with the weather we have but use the above as a guide when you can.
I wish I had read this yesterday, as I tried to do 3x1 @ z4 in 90 degree heat. I would have been much better off hitting the treadmill as I feel like I've had the crap beat out of me today and didn't come close to hitting my marks. I finished five miles @ 10 min miles, and it was more like a fartlek run. Tonight, I'm going to try the trainer, which has historically been insanely difficult for me during the summer; whether it's because the air in our house is more humid or just 'cause I can't open the window I don't know.
Bear in mind that "heat acclimitization" does NOT mean that, after three weeks of training in the heat, you will be able to go just as fast/hard as you would in 60F weather. Ain't gonna happen. What will happen, is you will maximize you ability to sweat and to retain sodium, and other stuff which will let you slow down by the minimum possible. But you MUST go slower when temps rise into the 80s and above when racing.
As to training, IMO there is no sense in doing hard intervals in the heat, for any reason ever. So fans, early AM, shade, etc are all helpful. If you HAVE to do run intervals in hot temps, you should be OK doing stuff like 1-4 minute intervals @ IP or TP, as long as you allow enough time to FULLY recover, meaning your HR gets well down into the recovery zone. For me, that means getting it down to less than 60% of my Max HR. Longer stuff, you're not going to get a chance to recover as much if you want the intervals to help improve muscle fitness, so you'll need to go slower. The longer the interval, the more important the slowing becomes, until you reach a point where it's just not giving you much value (to your muscles) for the effort entailed, and you might as well just be doing LRP.
"Dry" heat is just as bad as "wet" heat maybe even worse, as it is not obvious to you that you are sweating. The dryness means the sweat evaporates very quickly, but you are losing just as much water as at the same temp in higher humidity. So you may not realise how much you need to drink until it's too late. Also, you lose a lot of "insensible" water with each breath in your exhaled air.
Running in this heat doesn't exist for me for anything over 45 minutes. It's inside and on the DREADmill for me! EX, just yesterday I ran 2:10 on the treadmill at the gym, for 14 miles. Hit all my targets too! It helps if you can find the mill nearest the a/c vent - so nice!
Were you "that guy" on the treadmill in your tri shorts?
This seems counter-intuitive to me. I had always thought that when it's humid, you don't cool as well because there's no evaporation; therefore you sweat more. If it's dry, you do lose water, but less of it. Live and learn.
I lost 4.50 lbs and fueled with 2.50 lbs of fluid. It was crazy and dangerous, looking back at that fluid loss. So looking ahead my plan is to run a portion on the road and hit some hills then pack it up go to the gym and finish the run on a treadmill. As much as I don't like that treadmill the conditions for running outside are just not worth hurting my heart over with that kind stress.
The past couple weeks were hot and humid - yesterday it was just humid. Sun was setting, it was mid-high 70's - so not bad temperature-wise. In fact, my skin felt cool - totally comfortable in that regard. But the humidity was 85%+. Yes, I had more sweat on my skin than normal because of lack of evaporation, but it was still evaporating (as evidenced when I would stop briefly, and sweat would start to pool up again).
However, the entire time, my chest felt like it wanted to take in a nice refreshing breath of air, and all it got was a couple lungs full of moisture-ridden soup.
I'm a good 13 years removed from my Chem E background, so I can't recite and formula's off the top of my head, but both humidity and temperature affect air density (negatively), and as the air density decreases, so does the absolute amount of oxygen available. I'd say that depending on what your bodys' rate limiting factor is in terms of fueling your muscles and getting them to move you across the ground, decreased oxygen density and potentially compromised oxygen uptake could certainly affect ability to hit pace, or cause the same pace to require a higher HR as compared to the nice, cool air in October.