Heat Stress or Not?
This morning went for 2x20min@FTP. Temp/Heat index over 2 hours spanned from 83F/88F-85F/100F, humid, windy, sweat pouring.
My FTP recorded in normal conditions is 276W, about 4 W/kg. Started interval 1 @275W and faded to 263W. Started second "conservative" @ 260W and by min 11 could no longer hold 250W........Took 600cal and 2000mg of sodium over 2hrs. I did race olympic distance( slightly shorter) tri this weekend. I am not completely recovered but I don't think that would induce this fading of these proportions.
Anyone can share any experience with 2x20min@FTP in high heat/humidity. How severely does that affect your work.
Is it better to dial it down at the start and see what happens or just take it @FTP until you implode, like I just did.
Thanks.
Comments
This post is starting to look a little lonely, so FWIW here are some thoughts.
Temps at those levels should not be a BIG issue for cycling - remember the wind chill factor @ 22 mph +/-. The wind IS helping to evaporate your sweat away, so getting some fluid in both before the ride and before each interval (about 6 oz each time) does help.
BUT: 600 cal intake for this two hour ride? That may be a fly in the ointment. You should have enough fuel already in your system from liver and muscle glycogen to cover all your needs during a 2 x 20 FTP test with a warm up. Maybe a Gu packet between warm up and start of interval 1 if you must have something, but 600 cal in the GI tract is taking blood flow away from your muscles to your gut.
When I do hard workouts like bike or run intervals or a long (2 hr +) run, I don't eat for at least two hours prior, and nothing but one or two shot bloks (30 cal each) during. For a long run, I may have 1 or 2 gel packs (100 cal each) during.
I ended up riding with a few friends and decided not to test, I think it may have been the hottest ride of my life. I drank 3 bottles of water in 1.5 hours and and my bike shoes, along with everything else, were completely waterlogged. But what was weird though was aside from sweating like I've never sweat in my life I didn't feel that bad. I didn't do the 2x20s but I did a 5 min interval at 315 (~4.4 w/kg) and soon after a 10 min at ~290. I'm pretty sure I would have popped had I done longer intervals, but I was suprised that if I did like Al said and drank before and after each interval the heat almost seemed to help my legs for short hard efforts.
If I really had it set in my mind to do the 2x20 (2') though I think I would have just headed to my basement, fired up the fan and did the test on my trainer. I never test as well on the trainer as I do on the road but it at least helps eliminate external contributing factors like weather extremes.
I agree that you should be able to ride fine when it is that hot, totally different story than running. Eating way too much before or during and or being shelled from the weekend is a totally different issue than the heat. That is more calories that I can properly take in at IM intensity, at FTP I can take in closer to nothing. Doing a test and ending up 15 watts lower than what you were aiming for is really not all the unexpected anyhow. Some days are better than others. 15 watts is about 5% right? Some days I feel 5% better than others for sure.
Thanks guys. Trevor, that is exactly where I was going with this. Power does drop off just like the run pace with heat and humidity. Longer intervals usually do reveal that better than short. You are correct. This is from literature and personal experience. Just like you, I had 3 bottles in 1hr 45min and could have had more. Lost 7lbs by the time I came back. I weigh 156lbs.
I agree that 80-85F with no to low humidity should not affect performance much if at all. That is due to cooling of the breeze that we are creating while riding. Now, at 85F put 82% humidity and now you are pushing a heat index passed 95F. I was drenched like never before as that sweat was not evaporating, it had nowhere to go. The implosion came all at once, felt ok, felt ok, yeah sweat going into my eyes at 25mph+, little unusual, than boom, legs dead, struggling to hold onto 250W........That is how it went. Sounds like bonk, doesn't it. I have done it to myself running in heat before, many times, feels good, little warm, little hot, still ok, wham, legs made of lead all of a sudden. Typical for heat stress.
Thanks to all of you guys for chiming in. I appreciate having someone I can cry to. Will see this Sunday how it goes, olympic tri is on schedule, hills, heat, humidity and wind, Eastern Kansas baby.
Trevor, the race is on the same bike course as 70.3 Kansas, just the flat section is taken out and the lake is Lone Star, just a little south of Clinton. Should be "fun".
my two cents is that if you raced just this past weekend and then three/four days later attempt a test, then I would think it would affect your results. That would be two "race" efforts in less than a week... not sure heat would affect the results unless you weren't heat acclimated yet. 600 cals is a lot. at that high HR, wonder like AL if that was just too much. wouldn't that be your Ironman nutrition caloric intake and not race pace? wondering here, mine is 220 per hour for IM but less for a TT effort. you didn't mention your hydration the day before and leading up to the Test, so that could be contributing to it. only by imploding do you understand what NOT to do on race day!! lol. good luck in future testing and results!!
Thanks for all the good info. I will examine all the nutrition practices too. It was not a test, just a 2x20min(4min) that turned ugly.