Training in Heat/Humid conditions run Power or Heart Rate
Hey folks, I tend to throw my random questions within the groupme because its convenient for me, but I figured I'd post here as well.
I live in South Florida so it's warm all year round and I'm prepping for a 50k. At 6am its high 70's and goes up. I've been having issues keeping my heart rate down while training for long runs (10miles>). I am a power/styrd user, and I generally perform my workouts via power. My issue is its hot and my heart rate is not tracking 1 for 1 with where my power should be. I've had some really good runs where my HR has stayed in my long run zone (<143 HR) although it feels really slow pace/power wise (Zone 1) and I've felt really good, but others where it's been a fail. I've done a few things to help me with this.
- Do my long runs with the Desoto long sleeve cooling shirt which when wet is designed to keep you cool.
- Focus on hydration (although today I purposely did not hydrate the last 5 miles of a 10 mile run in 85 degree temps with my cooling shirt and my HR stayed in the correct zone while progressively runner faster sooo not sure about this, but for a 50k im sure this should be consistent)
- Just leave heart rate on my watch and not worry about pace.
I'm sure I answered my question, but I'll still phrase it here. When its hot and humid 80 degrees>, should you
A. Run by Power
B. Run by Heart Rate
Comments
B. Just like on the bike when it's hot and humid, forget about power/pace and monitor HR and use RPE.
On some of your training runs, I suggest not looking at your HR until after your run in order to tie RPE and HR and pace together. IOW, when you're running 10:00 miles you should be able to guess your HR +/- 3 bpm and vice versa. This will prepare you in case your watch or HRM fails during the race.
What is the location and expected climate for your race?
@Derrek Sanks solid advice, thanks!
The location is Key West, Fl. It's the same climate as Fort Lauderdale.
OMG! We need to talk about race selection. LOL. At least it will be flat and maybe a nice breeze. 😂
Derrek is spot on, especially his suggestion to start learning how to sense the proper RPE to use for the HR you will racing at. Come race day, the numbers will probably not correlate the way they do during training, due to any number of factors: weather (temp, humidity), terrain, taper, adrenaline, etc. Meaning, I'm a firm believer in racing via RPE first and foremost. But you have to learn the RPE that is associated with the HR you learn through training that you will be able to manage mile after mile on race day. The pace & power (which are pretty much the same thing, in my experience) will then be what it is.
Al & Derek are dead on. For the run, as heat and humidity increases your HR will climb as well, so RPE is the way to go and getting to know the balance of RPE to HR will help you to not over extend. You will be running slower at a higher RPE/HR, as temps climb into the 80s with higher humidity, than you do at lower temps.
A while ago some super smart people put together a spreadsheet to help people estimate their IM marathon times based on temp/humidity, so if you need help narrowing down paces, etc. it may help although your race is a little longer. If nothing else it give you a feel for how heat impacts pace. It can be found here:
https://app.box.com/s/0sh530z6qjcf8k0oe4cc
I can't access it at work, but @Brian Terwilliger put a link to a Stryd spreadsheet on the Dashboard the other day, calling it a "Great calculator from Stryd just released on how to adjust your race power for heat, humidity, and altitude.".
Might be worth checking out.
Found it @John Withrow !
https://docs.google.com/spreadsheets/d/1KU9U6QdjWlvmsQXVsCj1AnKEzywNL0Hq5yXIwOcYLF8/edit?fbclid=IwAR1L2WXi8j_9LGITEt9Hbw3GFp3IpefbewFyJEpFgmrHQ9xf4Ln5YA3LPkk#gid=0
@maurice matthews
Is it the Keys100, 50k from Big Pine Key to Key West?
Looks self supported, with crew allowed to provide water/ice? Minimal Aid Stations?
31 miles in that kinda heat/humidity is no joke. Keeping the core body temp down so that you can keep moving forward with minimal slowing is your only goal. Sure use Power/HR as a limiter to keep yourself from doing anything stupid in the first hour, very quickly it will be all RPE, develop a run/walk strategy and complement that with a body temp management strategy, and use it right from the beginning. Something like run 1 mile walk 30" from the start until it gets hot (80-85?) then go to run 1/2 mile walk 30". Water/Ice on head and body , ice water towel on neck, ice in hands, shorts, pockets , in hat etc as often as needed or as often as possible. The DeSoto longsleeve shirt is my go to shirt for almost all outside training , however the theory of cooling is that its supposed to be more effective in hot dry conditions when the water can evaporate, many believe the shirt does not provide the same cooling effect in humid conditions, I'm not so sure as it also provides sun protection from direct sunlight, that full exposure feels so hot on the skin, so tough call on the longsleeve shirt or not? If you plan on using water/ice on the body, may I recommend a thin layer of Desitin coating your feet as well as a thin layer of lube , then socks, this should prevent your feet from becoming macerated if they are soaked for 4hrs or more. Definitely try that out a few times pre-race .
@tim cronk Yes, that's the exact race. I believe I hit 6 aid stations which is about every 5 miles. I plan to run with my camel back to carry my own hydration. So glad I posted this in here. You all have come with great GEMS. I like the DeSoto longsleeve for the the three pockets on the back which can be stuffed with ICE 😀(just thought about this LOL)
Maurice -
Age? Weight (or leanness)? Fitness level? Body type?
(I was going to ask about existing day-to-day heat exposure, but your location answers that for me ... unless you spend 99% of your time in A/C).
@Dave Tallo Hey Dave,
I'm 37, 5'5 168 pounds (stocky build/Running back build), hitting between 120-150 miles per month running 6 days a week. I did a 6hr race in January down here although it was on trail and I power walked it to keep my heart rate in low Z1 and ran towards the end. This race in Key West I planned to run and it's flat,road surface.
I played with this tool a little bit and it's really neat.
Do you know if there is there an HIM version of this? I've noticed that a lot of the EN tools are IM-specific.
@Janyne Kizer i helped put that together about 7 yrs ago. We only did it for IM. It was based on data from 10s of 1000s of individual IM run splits, correlated with hour-by-hour heat and humidity on race day.
NO HIM version.
T his comes up every year; we wrote some wiki posts so as not to keep repeating ourselves:
http://members.endurancenation.us/Resources/Wiki/tabid/91/Default.aspx?topic=Heat+Acclimatization
Thanks, @Al Truscott!
I see Patrick included a link to this thread in a recent email.
As posted above, if running with Stryd, give that heat/humidity/altitude adjustment calculator a try. What I’ve been doing is for anything Z3 and up I’ve plugged the current conditions info into the spreadsheet to get the adjustment and used that as my floor. I try to hit my actual zone watts, but if the conditions are just too much, I drop down to the adjusted power. Has been working great.