First Half-Century - Followed by a Blackout!
 

I just turned 50, and have only been riding for about two months. But I've been riding 12-15 miles every day during the week, and 20-25 miles on Saturdays and Sundays, so I figured I'd try a half-century on flat terrain on Sunday.

I got up early enough to have a protein shake and 24 oz. of water an hour before starting the ride at 7am. Then for the 3.5-hour ride, I'd stop every 45 minutes for an energy gel and 24 oz. of electrolyte water. I also drank periodically from a water backpack over the course of the ride (about another 64 oz. of plain water).

I finished the ride and still felt pretty good - not gassed out or "bonked" at all. But then I bent over to give the cats some food, and when I stood back up, I felt lightheaded for a second and the next thing I knew I was waking up on the floor with a sore elbow from where I hit it on the floor. My wife heard the crash and said that I was already coming to when she made it into the kitchen, so I guess I was out for 5-10 seconds in all.

My blood pressure was 110/60 right afterward, and stayed there for the next few hours ('normal' for me is closer to 120/70).

I don't think the distance was excessive, considering I'd been riding 100+ miles per week for several weeks prior. But I guess the moral of the story is that I wasn't as ahead of the "hydration curve" as I thought, and that there's a huge difference in how much water I need for a 50-mile ride compared to even a 25-mile ride.

Not a doctor, but I play one on the bike. "when I stood up" is the clue to me. your bp dipped significantly. your description of 45 minute "top offs" suggests no dehydration issue, just a bp drop. see if this sounds like you: https://www.runnersworld.com/advance...-but-fainting/

IMHO, you should have been up to a 50 mile ride without any difficulties. I think you should see a doctor.

How hot was the temperature?

Thanks for the article link - that does sound like me. I've occaisonally gotten a little lightheaded in the past when I've stood up too quickly; Sunday was just the first time I've ever passed out, or even come close to it. I've also lost about 50 pounds through diet and exercise over the past eight months, (I'm 6'2" and have gone from 230 to 180), so I think that's lowered my blood pressure as well.

I'm due for an annual physical, so I'll definitely bring it up. I felt too good immediately after the ride to think that the distance itself was excessive - I just think I should have drunk more water over the course of the ride. The article that blacknbluebikes linked to upthread mentions dehydration contributing to a drop in blood pressure when standing up quickly.

It was 70F when I started, and almost 90F when I finished, with humidity around 60%

I've benign paroxysmal positional vertigo (BPPV)...it comes and goes. Never have it while riding only when I'm relaxed and rise from a seated postion at home. Never blacked out with it, though it has made made me feel a little dizzy for a few seconds.

It's called orthostatic hypotension, it's not necessarily indicative of an underlying condition, and it's just a thing that happens every now and again to cyclists, because we participate in an activity that pretty much just uses the legs. Blood gets down there, wants to stay down there.

I have a pretty much perfect physical, am 2 years younger than the OP, ride a ton more (for a fair bit longer) and I'll still get a little bit 'o the woozies from standing up too quick (hopping up from the sofa) or rising from a bent down position, probably a couple of times a week.

I've had this happen to me after rides for decades, starting when I was in my mid-teens, some 50 years ago, although I usually don't pass out. Instead, I have to stand where I am for anywhere from 10 seconds to a minute or so before the feeling dissipates. Feels (and probably is) very much like coming out of general anesthesia.

Mildly unpleasant, but I figure it's the price that we endurance cyclists pay for developing a very efficient cardiovascular system.

Ah---I see that Dr. Isotope has elucidated the phenomenon clearly.

Could also be initial signs of heat exhaustion.

I get the almost passed out thing sometimes, especially if I've been riding a lot. A friend passed out while heading to the bathroom at 2:00 am last week. He saw multiple doctors and they came up with nothing. He did hit his head pretty hard on the floor.

I like to weigh myself before and after hot rides. I generally come home 5 or 6 pounds lighter after a 60ish mile ride with climbing and hammering.
Also, the color of your urine is an indicator. If it looks like orange paint, you might be dehydrated.

You're 48? Did you get a pass to be in this forum? Did you at least bring pie?

I didn't think any of you codgers were still allowed to have pie, unless it's sugar-free, and I refuse to buy that. I could bring you some rice cakes, probably. :roflmao2:

On topic, lower blood pressure can be a sign of severe dehydration; mild dehydration causes blood pressure to go up. From the sound of the OP, he put down over a gallon at a ~15mph pace. I don't think hydration is much of an issue here.

Yes, it did sound like he had enough water. Rice cakes? Lovely thought but I'll just have some styrofoam.

I can experience the same thing too if I jump up to quickly after a long strenuous ride. It's an easy fix though. I just get up a bit slower.

DrIsotope make mine rhubarb pie. If you can shape a rice cake into a crust for it that might be okay! Used to grow rhubarb when we lived in IL and MO, but the winters don't get cold enough for it to do well here. Root has to go dormant or something like that I was told.

i always thought they were the same.

kidding aside it happens to me too from time to time.

Could be a sign of coming into good form. Still, quite worrisome. A dear friend once passed out and hit her head on a doorknob, like instant Alzheimer's.

Protein shake + 88 oz. of water + 96 oz. electrolyte water + 4 gels, all for just 50 miles ???? :foo:

My longest ride prior to Sunday had been just under 25 miles, and I have a history of not handling the heat well, so I was trying to err on the side of "too much" rather than "too little". The "bottle of water and a gel" every 45 minutes was something I read here and it didn't seem unreasonable. The protein shake is just 150 calories and had nothing to do with the ride - it's my everyday breakfast.

Ditto, postural hypotension. Happened to me after getting fitter through endurance exercise, lower BP and HR.

Now I'm more careful about getting up, bending over, etc.

Sure, hydration and temperature are factors too.

And at 62 I need a rest day after most rides longer than 20 miles or so, especially harder rides in hot weather. I had a good 70 mile ride Saturday, pretty hard pace in hot weather, felt great. But Sunday I could barely stumble around. Felt better Monday night after plenty of rest.
​​​

Too much can be just as bad as too little so finding the personal balance is all important. As for protein, I had some 2 hours before Sunday's 52 miler that began in 84F temp and ended in 93F temps(SW FL). During the ride I had a 20oz and 24 oz water bottle, 1 peanut/chocolate snack bar, a Clif Shot Double Espresso 100mg caffeine gel and a Crank Sport e-Gel. For an effort of a marathon, Ironman Triathlon, hard 100 mile ride protein is 4 hours before with carbs and water closer to start. At 70yo I've had time to find my zone.


Experiment and BTW, congrats on your accomplishment. :thumb: :thumb:

I've always had a rough adjustment period after a hard ride. It's worse when hot. Doesn't matter if the ride is 30 miles or 200, after I stop I have a bout of light headedness. Blood pressure undershoot.

My PID control loop needs a bit of tuning, but I don't know where the parameters are stored.

Hello darkness my old friend,
I stood up too fast again

I’m still too immature for 50+ but my complex cardiac history wants to tell you be mindful

I get it all the time (3-4 times a week), but my root cause is something else entirely. Now I have what my cardio doc calls "highly labile bp" (and it can go really high, too). I just have to be aware of it and manage it. Such as: 20 minutes after a ride, increased probability of a drop; 20 minutes after eating, increased probability. Excessive overheating, like running for a train in a winter coat after drinking, increased probability (ah, yeah). Sitting semi-comatose in the gravity chair watching Netflix, stand up and "wooze." So, I say to the real docs (quite a few), what do I need to do? One, recognize when you feel it coming on, so you don't fall and really hurt yourself (one doc has a patient that is now paraplegic from such a fall). Two, when it starts, get your head down - I usually act like I'm tying my shoe, but I'm really trying to get my head next to my knees. Two(b), don't hesitate to sit on the floor immediately (hard to fall off the floor). Three, put something cold on the back of your neck. Four, you definitely know when it's gone, and it you're not sure, stay in a safe posture. And they all said "don't stop riding if it doesn't happen on the bike." Never has.

And of course, remember that Dr. Internet is not your friend and you should discuss medical issues with a legit medical pro. We're just a bunch of bike riders that think we're really wise.

:lol:

I have the same issue, but not so much after exercising. I am finding myself laying down more than usual (long story) and have a bad habit of just popping up and walking away.

OP: Be careful with it ... you can really eff yourself up with a fall. See a doc.