General Cycling Discussion - Heat stroke

Hi there,

I was wondering how much water everybody here would typically drink on a
30 kilometer (18 mile) ride ?

Awhile, I went out on such a ride. It was fairly hot and humid even though I set out fairly early in the AM.
Anyway, I emptied (drank) both the bottles on my bike midway through and got them refilled for the remainder of the ride.

However, in the last 10 kilometers, I started to feel weak and my head was starting to ache a little. I had been sweating profusely and stopped several times feeling a little ill.

When I got home, I realized that I had stopped sweating completely. I had a splitting headache and threw up several times. I was so disoriented, I left my place to go to hospital and went in the wrong direction, then collapsed. The paramedics were called by a passerby and I was taken to hospital where I spent two days being rehydrated and treated. They told me I had heatstroke and that my temperature was 105 when I arrived at the hospital.

So...obviously I didn't hydrate enough but I went through almost 2.5 liters of water.
Has anybody else had Heatstroke ?
I believe it is primarily from being dehyrdated right ?
Would it be better to fill one bottle with Gatorade instead ?

Justen
23, female and loving my new bike !

I was riding home from work yesterday afternoon, and only had 2 bottles of water, no sports drinks. I went through all my water, and when I got home, felt very weak, It is 18 miles from my home to work, and the temperature was 94 degrees F . I also had a headache, but I don't think I was as severe as you were. I would tend to agree that this would be more related to being dehydrated .

How much did you drink before the ride? You might need to concentrate more on hydrating before you head out.

Try to hydrate all the time and always before/after a ride. not just durring the ride.
For me i always have a bottle of watter handy durring the day, and comsume at least 1-2 liters a day,more when im real active in the heat.

Here is an article on heat stroke .It could be the exertional type where the heat and exertion together are the problem but certain illnesses and medications can also complicate this as well apparently so I would talk to the doctor to make sure those are not a contributing factor.As others said apparently hydration is key and like was said its best to start well hydrated and continue to drink fluids during and afterwards well. http://abcnews.go.com/sections/living/Healthology/heatwave_dangers.html

About 10 yrs ago I had heat exhaustion (not as bad as heat stroke) on a century MS ride...it was in the mid 90s with high humidity....riders were dropping like flies....at the finish they had shaded cots where they laid you down and then covered you with sheets that they had soaking in ice water...it really worked - within 15 minutes I recovered such that I could walk around again

Bad scene, Justen. I think I may have gotten heatstroke a little bit once. I was biking in 100 degree heat, and I started to feel dizzy and actually got the chills. I guess that was like a fever, higher body heat giving you the chills. Anyway, I just stopped and sat in the shade drinking fluids for a while. It eventyually passed and I finished the ride. In heat or on long rides, I take my 100oz camelback with me as well as a cage bottle full of sports drink. I found that it is important to get that stuff back in your system during hard riding.

I had a similar problem on the Shiner Bash this year. We latched on to a big dog group and were running about 5mph faster than our normal average. I remember asking my buddy if we could maintain and we decided to try.

Bad Idea, got dehydrated, too hot. Got the Chills, Goosbumps, dizzy. Had to stop 4 times in the last 4 miles (No, I would not sag....I guess my stupid male pride) Hurled twice. Seems odd that the body expels that much needed fluid.

Oh, well, I did make it in, and at my normal average speed overall though I had to stop more often. Had we just maintained our normal pace we would have finished earlier because we would not have had to stop so much.

Lesson learned. I will be better on the century I am doing tomorrow as well as the HHH in August.

No one has mentioned electrolyte balance. That could be a major contributor, with all the sweating.

Hydration begins long before my ride. At the very least, the night before.

DnvrFox is right on about electrolytes and sweating.

My first 22oz bottle has 70% Gatorade 30% water, my 2nd one has 60% water and 40% gatorade. Anything stronger on the 2nd bottle is just too sweet for me. That will generally last me for my ride 20-24 miles. Sometimes a plumb makes it into my jersey pocket.
I generally have to pee on my ride. If I don't, it's a good indicator I'm not drinking enough.
Another bottle of 80% water 20% Gatorade when I get home while I'm stretching and rinsing my clothes.
Another bottle of water while I eat a bagel or whatever, usually around the 30 minute mark.
Another contributing factor may have been you road to hard.
If my ride is longer than 40 minutes, I'll keep my % of max heart rate around 80% and try not to exceed 85% for any length of time.

There are a lot of good articles out there on proper hydration for cyclists.

Originally posted by DnvrFox
No one has mentioned electrolyte balance. That could be a major contributor, with all the sweating.

Hi there,

Good point ! I did exactly the same ride today as I did that day I had heatstroke. This time I drank plenty before I left and also had one bottle with iced gatorade and the other with iced water. I had to put ice in it because it is so hot and humid, it gets warm too fast otherwise.
I like the chilled drinks.

I feel just fine now and am going to down at least a couple of liters over the next couple of hours to recover.

Be careful folks - Heat stroke is nasty ! I learnt a valuable lesson and was very fortunate to have collapsed outside where I was seen and help was on the scene quickly. The docs told me it could easily have resulted in death as my body was no longer capable of cooling itself down.

Justen

Originally posted by Brennan
Bad scene, Justen. I think I may have gotten heatstroke a little bit once. I was biking in 100 degree heat, and I started to feel dizzy and actually got the chills. I guess that was like a fever, higher body heat giving you the chills. Anyway, I just stopped and sat in the shade drinking fluids for a while. It eventyually passed and I finished the ride. In heat or on long rides, I take my 100oz camelback with me as well as a cage bottle full of sports drink. I found that it is important to get that stuff back in your system during hard riding.

Hey there,

Thanks for your message. Yeah..it was horrible. The headache that I got was absolutely horrible. I felt like somebody was pounding a spike into one point in my head over and over again. And the hurling - yuck..that was nasty too but I guess is just the bodies way of reacting.

I think the chill you described may have come from your body having trouble regulating temperature. It does sound like you had heatstroke, especially with that chill and the dizziness. I think the chill may have come as your body tried to somehow cool itself off but it was clearly having trouble trying to regulate your temperature.

I did stop in at a firehall as I was feeling so ill. They offered to call an ambulance at that point but I just wanted to get home. I don't think I was thinking that clearly at that point. Anyway, they gave me a bunch of wet papertowels and some cold water and I headed home. I wish that I had taken them up on the ambulance thing. I probably wouldn't have become so sick if I had just gone to hospital at that point.

Justen

Remember to avoid the combination of ephedra, sudafed, type substances with caffeine since there is a high incidence of heat strokes related to using them in conjunction. (These were the main mechanism felt to be the cause of the string of professional athlete deaths who used ephedra like substances... but that is another whole drawn out topic....just keep that in mind.)

I am continually amazed at the differences in people and their responses to such stress factors as heat and cold, for example.

Prime examples are my wife and myself. I can go for a 50 mile ride in temps between 95-105 with just a bottle or two of water which I may refill once along the way and some Grandma's cookies with a stop along the way for a sandwich, and be perfectly fine and ready to go at the end.

Her body would never allow her to do this, and she would be in extreme distress immediately. Heat prostration (weakness, etc.) would start almost immediately and we would have to take severe emergency measures to prevent things from going further.

This creates in me a need to not set her up for failure in riding when, to me, the conditions are perfectly acceptable for a nice bike ride, and for her they are downright dangerous, as she occasionally reminds me.

Similarly, I am not much susceptible to cold, while she is.

So, what causes that difference in people? Is it male/female. It is not age in my case as she has been this way ever since we got married almost 40 years ago.

Any thoughts as to what are the physiological factors in folks that cause such a wide range in responses to stimuli?

Originally posted by DnvrFox
I am continually amazed at the differences in people and their responses to such stress factors as heat and cold, for example.

Any thoughts as to what are the physiological factors in folks that cause such a wide range in responses to stimuli?

Good question !
I am not a physician but would hazard a guess that some underlying medical conditions can make some people more susceptible to heat/cold conditions than others - particularly under exertion (like exercise). I have a younger sister who is very light complexioned and she does not do well at all in the sun. While one of my other sibs is darker (although we are caucasion) and can spend hours in extreme heat with no difficulty.

I do have fairly severe asthma and find it much harder to breath in hot weather but I believe that dehydration was the main factor in my heat stroke.

I wonder how much of a factor age is ?
Certain medical conditions and medications can make you more prone to sun and heat sensitivity as well.

Justen

Originally posted by cbhungry
Remember to avoid the combination of ephedra, sudafed, type substances with caffeine since there is a high incidence of heat strokes related to using them in conjunction. (These were the main mechanism felt to be the cause of the string of professional athlete deaths who used ephedra like substances... but that is another whole drawn out topic....just keep that in mind.)

hmmm..I do use decongestants during the spring and summer to control my allergies. I had taken my regular dose the morning that I had this heat stroke but not in combination with caffeine or ephedra. Still, this is good to know as I have taken ephedra in the past.

Justen

I'm with the others who say that hydration before the ride is the key. If you were dehydrated before the ride and tried to correct it during the ride it would have just made it worse as your body would have used energy in absorbing it while you were trying to make it do something else.

I've ridden in temps a lot hotter than 105F without those sort of problems. I make a habit of drinking 5-10 litres of water/day (regardless of riding patterns) as a matter of general health. If you had started properly hydrated you probably wouldn't have felt the need to drink 2.5 litres during the ride.

Justen, it sounds to me that you had a bout of heat exhaustion, which is different than heat stroke. I got it back in 1972 painting a fence in the heat. I had the same symptoms as you - stopped sweating, headache, vomiting, disorientation. I understand that the way to tell if it's heat exhaustion is when you stop sweating and then your body overheats. Took me a couple of days and lots of Gatorade to get over it. The doctor also told me that once you have heat exhaustion, it's easy to get it again. The key is to take it easy on really hot days and keep the fluids flowing. Glad you're feeling better now.

Originally posted by Chris L
I've ridden in temps a lot hotter than 105F without those sort of problems. I make a habit of drinking 5-10 litres of water/day (regardless of riding patterns) as a matter of general health. If you had started properly hydrated you probably wouldn't have felt the need to drink 2.5 litres during the ride.

Hi Chris,
Yes, I understand that now but it was still very hot and humid and although I did drink some water before I left, it obviously was not enough.
BTW...the temperature was not 105 degrees. That was MY temperature when I was first assessed in the Trauma bay.

Anyway, I have learnt my lesson - drink lots before you cycle..and during and after.

Justen

Originally posted by Justen
Hi Chris,
Yes, I understand that now but it was still very hot and humid and although I did drink some water before I left, it obviously was not enough.

The water you drink before setting out needs to be spread over time. If you try to put away four litres in one hit before setting out, it will only cause problems. As I said earlier, I treat drinking a lot of water as a matter of general health - I find I perform better in virtually all facets of life if I'm well hydrated. It's not something that can be dealt with by just "loading up" five minutes before setting out.

Originally posted by slotibartfast
Justen, it sounds to me that you had a bout of heat exhaustion, which is different than heat stroke.

Ah..no. It was Exertional Heatstroke according to the ER physicians. I would think they would be qualified to make such a diagnosis so that is what I am going by. Although, they did tell me that it would have started out as heat exhaustion.
I had stopped sweating, my temperature was pretty high, I had been confused and disoriented, then I collapsed. They did some blood tests and a CT scan as well as using a cooling blanket and fan. I also got a bunch of IV fluids.

Anyway, regardless - I know that I did not hydrate properly and that a hyperthyroid condition apparantly contributed to the problem.

Justen

Originally posted by Chris L
The water you drink before setting out needs to be spread over time. If you try to put away four litres in one hit before setting out, it will only cause problems. As I said earlier, I treat drinking a lot of water as a matter of general health - I find I perform better in virtually all facets of life if I'm well hydrated. It's not something that can be dealt with by just "loading up" five minutes before setting out.

No..I am well aware of that. Admittedly I should have had more water to drink the day of the heatstroke but I'm not an idiot. I normally drink a fair amount of water through out the day. Over a two week period - I typically drink 36 liters of water (I use a water cooler service which delivers 18 liter bottles of water every two weeks) and about 12 liters of Gatorade which I dilute to varying degrees.

Ever since I got the cooler, I have been drinking significantly more water than I ever did before.

Anyway, thanks for the tips.

Justen

Originally posted by Justen
Ah..no. It was Exertional Heatstroke according to the ER physicians. I would think they would be qualified to make such a diagnosis so that is what I am going by. Although, they did tell me that it would have started out as heat exhaustion.
I had stopped sweating, my temperature was pretty high, I had been confused and disoriented, then I collapsed. They did some blood tests and a CT scan as well as using a cooling blanket and fan. I also got a bunch of IV fluids.

Anyway, regardless - I know that I did not hydrate properly and that a hyperthyroid condition apparantly contributed to the problem.

Justen

Well if you had stopped sweating, it was heatstroke and that is bad news. Heat Exhaustion is less severe. You feel weak but you are still sweating.

Electrolyte imbalances are similar. I can get hyponatriumia riding in the FL weather. I can get it if I ride hard for over 50 miles, swill down over 5 L and sweat a whole bunch. I can keep from getting it by eating table salt. Sports drinks do not have much sodium in them because to have enough to do any good, they would have too much sodium to taste good. It would be like drinking sea water. The symptoms of hyponatriumia are weakness, fatigue, disorientation, and vomitting. It can progress onto convulsions and death or so I have heard.

Even here in FL, most people do not sweat enough to have a problem with this. I am one of the lucky few.

I wonder about age and the heat too, because I am old. Is heat exhaustion mostly a function of age or physical condition?
When I ride with the Studs and try to keep up. I can feel the exhaustion starting, so I slow down to my regular speed. The problem goes away. I stay hydrated all of the time.

Originally posted by Wes
I wonder about age and the heat too, because I am old. Is heat exhaustion mostly a function of age or physical condition?
When I ride with the Studs and try to keep up. I can feel the exhaustion starting, so I slow down to my regular speed. The problem goes away. I stay hydrated all of the time.

Age could be a factor - although my Grandmother was playing Tennis several hours a day even into her 70's. She actually only stopped at 75 when her eyesight was failing but was still incredibly spry and much fitter than most her age and her adult childrens' age. She would play regardless of the weather and the heat never seemed to bother her.

I would encourage you not to try and keep up with the "Studs". Perhaps you could start a cycling group yourself and then would not feel the pressure to keep up but could still enjoy the comraderie of cycling in a group ?

I prefer to cycle alone for the most part - especially when I am doing it for exercise. I don't like to be pressured into going faster than I am able to or be frustrated by going too slow. I can go at my own pace and go wherever I want. When I am cycling for leisure, I enjoy the social part of it and we just cycle and chat.

Back to your original question though - there are some that seem able to tolerate the heat much better than others - regardless of their age. I am not one of them and I am 23 years old. I just came home from another 40 Kilometer trip in extremely hot and humid conditions but have figured out the right formula for hydrating and feel fantastic now. No sign of heat exhaustion at all.

Just take it easy, have fun and don't push yourself or you will suffer some physical effects and won't find cycling as appealing. That would be very sad.

Justen

From what I have found age can factor into this due to the sweat mechanism becoming sluggish as one ages and decreased aereobic capasity.Women are at a disadvantage due to generally lower aerobic capasity.Fit individuals would be more tolerant of heat due to greater aerobic capasity.Obese individuals generally have lower aerobic capasity and as well based on their mass to surface ratio,it is more difficult to cool themselves.Also don't overlook the importance of gradual acclimitization to the heat as an acclimitized individual will have a lower heart rate,lower blood pressure,higher sweat rate and more dilute sweat.Apparently it takes an unfit individual 50% larger to acclimitize to a hot environment than a fit individual.
As Pat said too much water too quickly can become a problem without accompanying electrolyte replacement as it dilutes sodium and other minerals lost in the sweat creating many of the same symptoms as exertional heat illnesses though without the high body temperature.

>>I would encourage you not to try and keep up with the "Studs". Perhaps you could start a cycling group yourself and then would not feel the pressure to keep up but could still enjoy the comraderie of cycling in a group ?<<

Now I am getting nauseated.

Originally posted by Wes
>>I would encourage you not to try and keep up with the "Studs". Perhaps you could start a cycling group yourself and then would not feel the pressure to keep up but could still enjoy the comraderie of cycling in a group ?<<

Now I am getting nauseated.

Whatever. Maybe I was off the mark but I did not intend this as an insult to the original poster.

There's no need to insult me for it, is there ?

Justen