Heat Exhaustion

Iona

Hi there,

I rode in a very hot and humid 75 mile bike event yesterday - and during the final 25 miles I could barely take in any water (let alone gatorade, solids, etc) because I felt so sick. Not knowing how I managed to, I finished the ride and a few minutes after vomited. I tried to cool down and sip water and went home to lie down with ice packs and fans, etc. Anyway - an hour after finishing I felt worse and was really violently sick. I don't think I've ever felt so bad in my life!! My husband became increasingly worried and called an ambulance. I was taken to hospital with heat exhaustion and was given four drips....

Any tips on how I can avoid this kind of thing in the future!? My legs felt fine and I felt fit enough (I've done almost this distance in training numerous times) - but the weather was brutal. I'm very, very fair.... am I destined only to ride in cool conditions?

I should add that I saw two riders outstreched on the road 15 and 2 miles from the finnish line with seeming the same problems - and medical assistants around them...

Thanks for any tips...

dhk

Sounds tough. I've never had a problem that severe, but have noticed that I run an elevated HR in the heat.

Tips: Expect to slow down in the heat. If you've got a HRM, use it to keep your effort down. When you see your HR starting to climb and not come down, it's an indication of either a rise in body core temp, or beginning of dehydration. Time to stop for a cold drink.

Without an HRM, when you notice the legs are burning or breathing getting heavy, time to stop in the shade for a tall cold one. You might need a liter an hour or more of water/Gatorade. I drink about 2 or 3 bottles of water for every Gatorade bottle in the heat.

I'm fair skinned also, so I know how sunburn will add to heat stress. Use SPF 50 sunscreen, and reapply as needed.

If all else fails, avoid the longer events in the heat. I passed up a Century last weekend in part because of the heat. Having to ride 100 miles in the blazing sun with a 100 degree heat index isn't really my idea of fun. Besides, plenty of great Century events are coming up in the fall.

Iona

Yes, it was tough! I went for a ride yesterday and, while I don't have a HRM yet, I could sense that my HR was still above normal and my stomach was still queezy. During the 75mile bike ride I stopped at all the rest stops and took on extra water, a little gatorade, and something solid to eat. Unfortunately, I couldn't stand to slow down.... I was thinking to myself, 'the sooner I get back the sooner I get out of the sun"!! This is clearly the wrong kind of thinking... and I should have taken an extended break at the 50 mile mark; not least because that's when my GI seemed to shut down.

But perhaps I'll put off a planned late August centry until the end of September when it should be much cooler!

Thanks!

Cowboyathlete

Where did this ride take place, and what were the temp and heat index readings that day? I am in Houston, TX. The heat index is already 108 and climbing. If it is not any cooler by sunset, I may skip my usual Tuesday ride. Death ain't worth it.

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Iona

I'm far from you - and not in a place usually associated with high temps - but it was certainly high for me! I'm in Southern Maine, and the heat index, I believe, was in the mid to upper 90's. The humidity was 90% as one point - which made the air quality pretty bad and probably increased the heat index. I think I'm used to sub-zero weather! I'm sure that in Texas this might be considered a cool day... but if I were you I'd think I'd skip the workout. I think I mentioned in an earlier post that I saw two other riders stretched on the ground with medical staff around them - only a few miles from the finish... so I wasn't the only one!

rlimbert

As someone who's also fair skinned, I find that sun, more than heat, is my problem. I can handle heat as long as I'm in the shade (with the usual caveats - drink a lot, don't push too hard, etc.). And it isn't just sunburn - I can SPF myself and I won't burn, but being in strong sunlight still just feels bad to me. It's as if I'm genetically programmed to avoid it.

As a practical matter, this means riding late in the day from about May through August. My worst experiences, though nothing compared to yours, involved riding on hot days right around noon. So I don't do that anymore.

Unfortunately, if you're riding in a scheduled event, or even a long ride where you might run out of daylight if you start in the late afternoon, that won't be an option. I'm supposed to ride a century next month, which will obviously take me right through the midday hours. Since it's in late September, I don't foresee a problem, but I probably wouldn't do such a ride in, say, July.

Rob

Iona

Hi Rob,

I'm very similar to you. Even when the temps are fairly coolish the sun really overheats me. Last Saturday was supposed to be cloudy.... it wasn't of course, and the sun was positioned as such that even roads swamped by trees offered little protection.

I generally head out very early - around 5 if it's going to be hot. I will certainly rethink when I schedule an organised event. Ordinarily I wouldn't have done it but I had sponsorship...!

Iona

kf5nd

Heat index 110 here today in Houston. Consequently, I am not riding today.

Otherwise, I drink about a quart of fluids an hour, taking a drink every 10 - 12 minutes (I am reminded by my count-down timer on my watch)

I supplement electrolytes, either with sports drink or electrolyte gels or caps

I keep heart rate down by watching monitor

Haven't had problems recently

jflumerfelt

I also did the MS150 in Maine last weekend and it was certainly hot. I'm not surprised many folks had heat related problems. The key to success is the right balance of hydration and electrolyte replacement. On a hot (and very humid) ride, a good rule of thumb is a minimum of a litre per hour of water and 500-1,000 milligrams of an electrolyte replacement formula per hour. I use either Endurolytes made by Hammer Nutrition (hammergel.com) or Thermolytes made by Sportsquest (carbopro.com). Liquid products like Gatorade usually don't have the right balance of electrolytes relative to carb needs for these kinds of situations, and peoples' needs vary widely. The above products are widely used by triatheletes, etc. in combination with their favorite carb supplement. Its very important to hydrate enough, which everyone knows. However, if you over hydrate without electrolyte supplementation you can get into real trouble since the water dilutes your remaining electrolyte balance.

Hope that helps.

Iona

I trust you faired better than I! Thanks for the product information - I shall certainly check it out. In general I have very low rates of sodium in my system (every blood test indicates this) - so I'm also going to try to intake more sodium in general.

It was a little cooler on the Sunday... but some rain! I was sad not to be able to take part. I did see the riders on their way back along the 114 (I live very close by)....

Iona

Iona

THE HRM is a great idea - as is the timer. As for electrolytes - what are 'caps'?

Iona

Otherwise, I drink about a quart of fluids an hour, taking a drink every 10 - 12 minutes (I am reminded by my count-down timer on my watch)

I supplement electrolytes, either with sports drink or electrolyte gels or caps

I keep heart rate down by watching monitor

Haven't had problems recently[/QUOTE]

kf5nd

By caps I mean capsules, Endurolytes made by Hammer Nutrition (hammergel.com)

I also use e-gel from cranksports.com


[QUOTE=Iona]THE HRM is a great idea - as is the timer. As for electrolytes - what are 'caps'?

Iona

jflumerfelt

Each of the websites I mentioned has good nutritional info about carb and electrolyte use. You also probably weren't doing yourself any favors by eating solid food at the rest stops, unless it was just a bananna or something. I couldn't imagine eating one of those sandwiches they were making! On intense rides like that you're often better off with things like hammer gel and/or carbo pro since solid food takes energy to digest and really doesn't start pumping energy into your system for a couple hours. I've found that 300 calories per hour of liquid carb mixture plus 1-4 electrolyte capsules per hour can get me through rides up to 6 or 7 hours. Also its important to get a protein and carb recovery drink as soon after the ride as possible.

dhk

I'd say water and electrolytes are more critical in the heat than eating. Too much food really seems to sit on my stomach when heat and HR is high. Last Century I rode on 3 July had the PB sandwiches and bananas cut into quarters which was just right.

Despite doing everything right though, extreme heat and sun is still a stress factor. My HR seems to run as much as 10 bpm higher on a hot sunny day. If you have to ride through the heat in a long event, believe slowing down and watching the HRM is still a smart thing to do to ensure you'll still be having fun at the finish.