rsbob 

https://www.sciencedirect.com/scienc...6041202031864X

Many impaired physiological functions which may contribute to heat stroke as we age. Be careful out there.

Condensed summary: https://www.nytimes.com/2023/07/20/w...e=articleShare
Heat Affects Older People More. Here’s How to Stay Safe.

Last summer in the low 90s after an hour ride, and drinking liberal fluids I became extremely dizzy and had to sit on the ground in the shade to recover. This explains why.

Biker395 

Well, for whatever reason, I can confirm this ... I am less tolerant to heat than I used to be. I used to go out in temps well in excess of 100F and as long as I drank plenty, I actually felt good doing it. Not so much any more. I tire more easily and am more apt to have the same symptoms you did.

DiabloScott

Not surprising I guess - your body's ability to cool itself gets worse, and its ability to function under heat stress gets worse with age.
Heat illness is one of those things people tend to dismiss, until it happens to them. Serious problem.

MikeWMass

Very thorough treatment of the subject.
Despite the graph cited above, most of the article was talking about longer term (days) exposure.
Clearly anyone with impairment of autonomic nervous system function or fluid regulation (diabetes, kidney disease, autonomic neuropathy, dehydration in the short or , d term) is at higher risk.

I must say, that at 71 I seem to sweat more than I have in the past, despite their saying that sweating decreases with age.

Iride01 

I'm not positive, but I don't think I sweat quite as profusely as I use to. I still break a sweat just going to the mailbox, but riding a bike, while I still get soaked and drip, it's not quite as much as I remember. And that does worry me since I ride even when the temps are hot. Today I downed 50 fluid oz. from my bottles in just 1hr 45minutes on a ride. That surprised me. But I did forget to down the usual 14 oz glass of water I drink right before I go out.

It was about 95°F and a little above, so I probably should have taken a third bottle.

GhostRider62

Being fat is 3.5x risk for heatstroke.

I seem to do less well in the heat as I age but my % BF seems to be a bigger factor than my age.

big john

Just wait until you're my age, Sonny.

50PlusCycling

This is true. In my younger days I was a medic in the Army, and spent most of my time working in training units in Georgia and Alabama. On any given day I would see at least a dozen cases of heat exhaustion, and an occasional case of heat stroke. Trainees and soldiers who were overweight were indeed more likely to fall out from the heat. The main preventative measure for heat-related health problems was proper hydration, and it was effective. I remember a company in basic training being marched back from the obstacle course on an August day. The drill sergeants of the first two platoons had made their trainees drink water regularly, the third had not. As soon as the company was halted, half of the trainees in the third platoon collapsed from heat exhaustion.

Stay hydrated, don’t push yourself too hard, and if you are overweight, pay even more attention to these two things.

bikemig 

I grew up in New Orleans and used to do long rides in hot, muggy weather. I handled it OK but I was young. Fast forward a few decades, I don't sweat as well as I used to and I now live in the Midwest. I ride early in the morning and do a ride that has good tree cover.

Bottom line is that I've always respected heat having grown up in it and seen what it can do.

GhostRider62

I have done a lot of distance cycling in 100-120F temps. Your point of not pushing yourself too hard is key. You can see a relationship of HR to Power go to hell in a handbag over a couple hours and once you overheat, it is hard to cool down. Rather, it is better to go a little slower and be consistent (and not over heat). When my BF is 10% (very lean for an oldie), I don't easily overheat. It is now 20% and on hot, humid days, I really feel it. That extra 20 pounds of fat is enormous and most older people like me are carrying extra fat.

Kabuki12

Yep , I had an episode that scared me last year during one of my rides . I have ridden in all sorts of weather , hot and cold , but never had heat related exhaustion . I left my house early as the weather was predicted to get in the triple digits by afternoon in my area. It was in the mid to upper eighties by the time I got out into the orchards . I could feel the heat coming from the asphalt so I opted for a shady canyon ride . It is about a 5 mile ride shaded by huge Oak and Sycamore trees . Not a huge climb but mostly uphill to the turn around spot. When I stopped to drink some water before heading out I felt very warm so I spent some time in the shade drinking water and soaking my cap with water before the downhill out. I hit 25mph without much effort and the cool cap felt great but didn't seem to cool me down as usual. At the bottom of the canyon I stopped to reassess and drink a bit more water in the shade . By then it was almost 100 degrees and I was not feeling well at all! I called my wife and she came and got me. I ride a lot , no real health issues , just over 6' and weigh 155 , so not overweight and will be 69 years old in a couple of months. I guess my body is aging as this would not have happened a couple of years ago . I now watch the weather and I am not going to push it in hot weather , it ain't worth it!

Biker395 

Lol ... at my rate, I'm not sure I'm gonna make it!

10 Wheels

I went Night Riding to beat The Suns Heat.

OldTryGuy

Got out at 2:19AM this morning for 25.52 miles with weather being -- Temperature -- 81 ℉, Humidity -- 87%, Feels like -- 89 ℉

big john

Back on the bike yet? Sure hope you're feeling better.

Fredo76

I have learned that if I get hot enough to need to pour water over my head to cool down, I will likely need to keep doing that all the way home. it's sobering to realize how quickly your coordination, balance, and judgement can leave you, in a dangerous situation. That 70+ yo man who died on a hike through Death Valley recently had plenty of hot hiking experience. His wife said that he thought that he'd be OK. When it happens, it happens fast.

Be careful, indeed.

CliffordK

Still in my mid 50's, I believe that I am reasonably temperature tolerant.

I avoid Air Conditioning as much as possible. I have for years. I believe it is harder on the body to work outside in hot weather, then run into an ice chest.

Most of the temperatures around here top out in the mid 90's, although I have tried a few bike rides in 100°+ weather.

I also tend to let my house get a little cooler than average in the winter, with the opposite effect.

rsbob 

In my 30s I looked forward to group rides in the high 80s and low 90s (hot by PNW standards). I seemed impervious to the heat and would excel while others started to drag. On those rides the whole group would stop to jump in a river or lake. It was amazing that we would be dried out in 5 minutes after we continued on.

Fast forward 30+ years, with the self generated winds cooling effect at those temps I feel pretty good until I don’t, and then, wham. In the mid 80 degree range, I carry an extra water bottle to pour on my head. So when it’s high 80s, I use the trainer.

Two years ago, I made the call of shame while attempting a 42 mile mountain bike ride in the mid 90s. Made it 32 miles and knew I was in trouble after downing 4 large water bottles, a huge iced drink and taking a cold shower in my gear/kit at mile 28.

I prefer the 60s temperature wise.

Maybe it’s time to go jump in a lake.

Iride01 

Mid sixties and less is cold for me! My legs don't work as well for me in those temps. Even in the seventies my legs don't seem to perform as well as they do in the eighties.

downtube42

I have not read through the whole article, but enough to get the idea: heat tolerance declines with age for real reasons. The bit about the reduced thirst response is new to me, and useful to know.

When it's 80's or more, I'm seeking or the shady way even when walking. That's the behavioral response to heat, which fortunately is still working for me.

In my 50's i moved to west Texas from Indiana, rode in dry 115 degree conditions, and my body managed. I didn't enjoy it, and avoided the heat when I could, but I rode a full super randonneuring series which meant full days on the bike.

Now at 62 I've moved to the PNW. I doubt I could handle those conditions if i wanted to, which i don't. I did a 600k up in Seattle early this summer, and we had unseasonably hot weather. Mid 90s both days was rough.

Calsun

The problem is one of dehydration coupled with high humidity that results in the body's core temperature rising above 105 degrees. At that point the body starts to shunt blood away from the head and the heart has to work a lot harder. Most heat stroke cases result in a heart attack and that is what is put on the death certificate.

Our bodies are designed to work at 98 degrees and hotter than that they work very hard to maintain the core temperature. Higher than 105 degrees and body functions cease and the internal organs melt.

I had run cross country for years in the California deserts in 100+ degree weather and did fine. The first time I road my bike 100 miles to Cabazon to stay with friends I came close to heat stroking as a result of the heat waves off the asphalt. I had to make cooling stops to make it to my destination without passing out. When I moved to Dallas and would ride in the summer months I became aware of how poorly my body adjusted to the heat with the humidity at 80% or more. My ability to cool my core by sweating was greatly reduced and it became necessary to join a gym with air conditioning and do my summer riding on a stationary bike. A local Dallas man participated in the Olympic trials for the marathon and died from heat stroke during the race. No doubt he thought he had acclimated to the conditions and was not going to affected as much as the other runners. He was dead wrong.

Even today when marathon runners die during a race the blame is put on their hearts and not on heat stroke which would create a liability problem for the race organizers. With our warming planet the marathon is becoming a high risk and increasingly deadly sport.

One problem as I aged was that my enlarged prostrate reduced the amount that I could empty my bladder and so I drank less water as a result. After a prostatectomy my bladder is no longer restricted and I am able to drink at least 4 times as much water each day. When I give blood every 60 days the tech often is surprised at how well my blood flows and it is the result of my high level of hydration.

In ultra hot weather I wear a hat, stay hydrated, and avoid asphalt surfaces. One of the advantages to have mountain bikes in addition to my road bikes is riding on dirt where it is always going to be cooler than out on a paved road.

big john

It's been over 100 for 13 days straight here and will be for the foreseeable future. That's when it bothers me ,when it just goes on for weeks. The last few weeks I have done lots of climbing, but have kept most of the rides under 50 miles. Yesterday we started early and climbed a canyon with steep walls and lots of trees that made a lot of shade. We were finished by 11:30, before the predicted high of 108 came to be.

Don't have a good a/c at the house and I think my old cat is suffering the most.

CliffordK

My cats are all less than 3 or 4 years old. They spend most of their time outside during the summer by choice, although I think they can find cool shady areas. The oldest one has mid to long hair. Good to keep her warm in the winter, but not so much in the summer. LOTS OF SHEDDING.

teacherman62

I'm glad to see this thread. I restarted riding in my early 40s, and found I was insanely tolerant to high heat riding, to the point where if it was 100˚ with super high humidity (eastern Kansas),I was mad if I couldn't get out for a forty mile ride. Couldn't find anyone willing to ride with me. Now I'm restarting again at 63, in the hilly Shenandoah Valley of Virginia, after a midlife adolescence that involved a new Harley, complete with the attendant lifestyle... 🙄. Got clearance from a cardiologist to train for a century in October. Did one in 1973, a few in 2003, and 2023 looks to be a good year for another. PVCs in heart rhythm are apparently an actual thing.

My ego struggles to admit that I might not be quite the thermophilic bike animal I once fancied myself to be. I still like the heat, and can tolerate it better than most, but I do notice a slight decrease in heat function. What really bites is going from a reliable 16-17 mph to 13 on a good day. Yeesh. Hills are harder, to be sure. I did not stay in shape during the Harley years, and I did marry and have a son, a process which somehow magically transformed a hopped up Road King Classic with added tour pack into a new Subaru seven years ago. My son, now 9, is becoming an avid rider, which I rewarded with a new Specialized Allez the other day. The hope is that we can do a century together. That boy can climb some hills. He overheated yesterday, and I did not, for what it's worth.

I think electrolyte supplementation is key. I use something called Liquid IV, which I get at Costco. It tastes good, and has some sort of theanine caffeine relative which also helps keep airways open. Additionally, the high salt content of my smoked ribs and brisket hobby moves from the inside to the outside of me remarkably well. I do think many people underestimate just how much salt is lost exercising in the heat. I know there is a relationship to blood pressure, and that needs to be balanced and monitored, but the term "hyponatremia" is not a hoax.
I also retired from teaching at 57 and started a tree trimming/climbing business because it seemed safer... I still do that in my own back yard, and it is strenuous in the extreme. Aging well involves seeking out physical discomfort, I'm afraid. Staying lean is a big part of that as well. I'd like to shed ten myself.

I hope nobody gives up on themselves because they have a heat event. I had a bad one on July 4, 1982, which I sort of barely made it through. Please keep your electrolytes up out there...

I also managed to log 30+ "pack years" along the way, a not-so praiseworthy term that gets me an annual fancy chest X-ray. One hopes those days are forever past... 😉

Calsun

You do not need electrolyte replacement which is something put out by the Gatorade marketing department. The company pays the NFL teams to use their product and advertise it on the sidelines.

If your core temperature is over 103 degrees it needs to get in a cooler environment to recover. What is essential is staying hydrated to keep your blood as thin as possible and minimize the stress on your heart. Heat stroke victims have core temperatures of more than 105 degrees and then go into cardiac arrest as their hearts cannot cope.

In Phoenix the temperature of the asphalt gets up to 170 degrees. That heat is reflected back up to anyone one it whether they are walking or bicycling. Qutite a few people getting admitted to the ER with third degree burns on their feet when they have been stupid enough to go outside barefoot.

Buy a cheap thermometer and use it to check your body temperature. Nothing high tech or expensive is needed to determine your current state. And wear a long sleeved shirt and a hat and try to stay out of the sun and off the pavement.

Glad to hear you are letting your cats outside in the heat. Two many free roaming cats as it is and a few less is good for the local wildlife.