How much does running in the heat effect your performance?
I have recently (within the last 30 days) had two very difficult runs in the mid morning to early afternoon heat.
My overall fitness is increasing; my 8-10 milers are getting faster and faster. Swimming going thru the roof with improvement.
I have been running 30-40 miles a week for a long time, but I haven’t done any LSD type of runs since my last Marathon in May. I do mid distance runs frequently.
But when I recently started adding some slower longer runs in the heat ,I hit the wall hard after only 5 or 6 miles. I mean could barley hold on to 10-11 minute miles, when I usually do 7:50’s to 8:15 on 10 miles. And I am not talking horrible sun beating on you heat, but 85-90 degrees even in the shade.
Is it possible that by running faster and faster in the 10 mile range, that I have lost “slower fitness”? If I go out on a faster pace I seem to have more energy.
My run today I started out slow in the 9 minute range, a little quicker for the first mile, kept about 9min pace until 7 mile point. Then, I had to struggle just to keep moving at any pace. (Like the last couple of a marathon) I just kept slowing and slowing, trying to keep moving forward, finally after about 5 miles like that (brutal), my HR came down and I started to feel good. I was finally able to run the last mile (up a big hill) fairly fast.
Maybe an energy source thing. In slow running I think it is 50 - 60 min that most switch over to more fat burning. Maybe the faster pace that you usually run keeps that change-over from being as abrupt, or happenning to the same extent.
Interesting question, since I am dealing with this right now. I had a Oly race on Sunday, and was very hot. I normally drink very little
water after a race, but this one I did like 5 bottles. Not good.
So, during my 2 training runs this week, I went in the afternoon while it was hot. In both runs, I cut them short, and was way slower then I have been for a long time.
I am going to go out real early tomorrow morning and see what happens. So, my plan is to try to get out earlier when it is cool, or just get in a short slow run in
the afternoon heat if that is all I can fit in.
Heat and the sun have a huge effect on performance. Not only does it take energy away from your body as it the body tries to cool itself down, but you will also get dehydrated much faster. While I would encourage wearing a hat/visor, sun glasses, and a little sunscreen to prevent some of the effects, I would caution you not to train in much cooler weather if you are training for a hot weather event. An important part of training is acclimating yourself to the probable conditions. Most importantly, keep drinking and take in salt tablets or capsules. It will help immensly. Good luck!
Yep, great inputs. I always run with a hat, and sun glasses, even when cool. Thats why I was trying to do some running in heat
since the races here now tend to be hot.
Heat can have a considerable impact on physical performance, especially if you have adapted to the dramatic temperature changes. I offer as exhibit A, Lake Stevens 2006. The temp was in the mid-90s, very hot for Seattle, and my 1:39 run split was in the top 50 for a 70.3 event with 600 people. I watched the field melt in front of me, passing 163 people on the run. It’s not that I am that fast, but rather the field had had very limited opportunity to engage in heat training. I had been running in Hawaii in the weeks leading up to the race.
That said, the impact should not take you from a 7:45/mile to an 11:00/mile unless there is something else going on, likely sub-optimal hydration or nutrition or poor pacing. The LSD thing doesn’t explain it either, your fitness would not fall off a cliff. I just think you need to spend more time in the heat before you know the root cause.
Heat does weird things to you, and it doesn’t take much in terms of degrees to make the difference. Just like all the people who complain if the pool is too warm, heat outside makes it more difficult to cool your body, which means more energy goes to that purpose as the body struggles to keep up. The only real fix for this that I’ve found is acclimatization. When we get recruits in boot camp, even though they might already be in good shape, we spend a bunch of time getting their bodies used to exercising in the heat, hydrating properly, etc. Also, running slower does use different muscles than running fast. Are you hitting the wall from a general energy standpoint, or from a leg standpoint or cardio?
Has anyone tried the glycerol-based supplements that claim to increase your body’s tolerance to the heat? I think Hammer makes one, and there might be others.
I also train in the heat of the day (Mid 90’s already). Should one do the mid and short distance runs outside to acclimate and do Long runs indoors on the dreadmill for pacing and performance, or vis versa.
Me too! I’m 6’2" tall, 160 lbs and absolutely die in the severe heat. I’ve been running at lunch once or twice a week to acclimatize and it is sooo hard. We’re into 100 degree heat and it doesn’t seem to matter how well fueled I am.
I know better now. I’ll take the runs out at a ridiculously slow pace to avoid complete destruction. When I’d go out at a “normal” pace I’d come back totally shelled. Halfs and IM kill me, because I’m off of the bike in some nasty heat. Prime time for a melt-down.
Funny thing is, in the few IM I’ve done I am able to pick up the pace as temps cool off. But the early run suffering totally ruins the day.
Not only does the heat have an impact on your performance, but the humidity does as well. As soon as the humidity kicks in my times get slower and I feel like I’m sucking in more water than air. Practice training inthe heat, especially if you have a race coming up and you know its going to be a hot one. Take extra water along to pour on yourself. This will aid in your body cooling itself. (Landis went through 70 bottles on one leg of the TDF last year.) You could also run with a small wet cloth around your neck or under your hat. This was recommended when we hiked to the bottom of the Grand Canyon in 100 degree heat and it worked great.
That said, the impact should not take you from a 7:45/mile to an 11:00/mile unless there is something else going on, likely sub-optimal hydration or nutrition or poor pacing. The LSD thing doesn’t explain it either, your fitness would not fall off a cliff. I just think you need to spend more time in the heat before you know the root cause.
Heat won’t do that…dehydration will. As a resident of the Floriduh sauna I weigh myself before and after every single workout, and I can easily correlate performance with hydration. I take salt tabs, etc to make sure that I am staying hydrated. If not I’ll go from a comfortable 8:00 pace to struggling at 10ish. Get an accurate scale and try this for a few weeks to see if that’s an issue. Anything more than about 2lb lost could be a problem.
All that said, if I can keep cool sweating well (and it evaporating) I am better off running a bit faster than slower…maybe it’s just evaporation rate vs energy expenditure.
Did you race the Boulder Peak today? That was as hot as anything I’ve run in – I was in the 7th wave. It was interesting to watch the pros running in even hotter weather. It looked like they were mostly drinking water and also splashing some on their face.
no!
Its killing me, but I had to back out to save my sore knee the punishment of Old Stage.
one of the toughest things I have ever done in training, was NOT doing this race. But my main focus this year is the Long Course at the REZ and NYC marathon.
how did you do?
OK, let’s be honest about the fact that a triathlon is not just 3 events.
It is actually 5 events:
Swim
Bike
Run
Dealing with the environmental conditions
Nutrition (primarily before and during the event).
So your issue is “the heat” and falls into the fourth event category.
There are some good posts in the forum for learning to deal with the heat. I have posted a few myself.
I encourage you to “search” the forum.
I now seek out the hot races because I have taught my body (of Northern European heritage) to excel in it.
Practice and patience will be your best allies in this battle.
Good luck.
Yeah.
Bikes have two wheels. Dont swim with your running shes on, some things are obvious…
Of course the “larger than life” details outside of the events make all the difference in the world. That was the point of the post.
I wanted to make sure it WAS nutriton and enviromental fitness , which pretty much everyone explained to me.
If I know my weakness, I can Improve it. Thank you and everyone else for the input.
I am startin to get it!
I did ok at the Peak. I knocked about five minutes off last year’s time – I saved about 8 minutes on the swim and two transitions, and lost about 3 on the run. I felt really awful after I finished, so I guess I went hard (for me, anyway).
As for the heat, I went quite conservatively on the bike – I coasted most of the downhills, was out of the saddle for maybe 20 seconds the whole ride and kept the pace quite manageable. Although my run ranking was about 200 places higher than my bike ranking, it was still by far my worst run leg of a tri. I am thin and I thought I was doing well on the fluids. I drank before the swim and kin T1 and drank most of a water bottle of Gatorade during the first 25 minutes of the bike. But, the heat still got to me on the run. The one change I’ll think about for next time is also getting a bottle of water on the bike (maybe at the first aid station). I think I could drink more fluid that way – having just a sports drink means that I slow down the drinking as I get that bloated feeling. Other people were suffering a lot more on the run, which is a minor consolation.
Sorry about your knees. I have bad knees and with a 34/25 (I have compact cranks) I can spin up Old Stage without too much stress on the knees.
Good luck at the 5430. That thing can be a scorcher – mid day sun with no shade.
