First some background. I'm 75 and have been riding nearly daily (except in winter) for four-plus years following bariatric surgery and a long history of diabetes, high blood pressure, high cholesterol, irregular heartbeat, etc, etc. Along with losing 120 pounds, I got rid of the diabetes/high cholesterol and reduced my blood pressure significantly (with periodic adjustments of my medication).

While riding -- and gradually building my comfortable daily distance to about 20 miles (sometimes more, sometimes less) -- I've closely monitored my sugar levels (since I now tend toward dangerously LOW blood sugar) and my blood pressure/heart rate. For more than a year, my blood pressure after a ride has been around 122/68 with a pulse rate of between 55 and 65. Occasionally, my after-ride PR dropped to around 45 or climbed as high as 75, but never higher, which initially worried my doctors a little, so they cut back on my irregular heartbeat meds (Carvedilol) with no observable results.

Over our horrible winter, I gained 10 pounds (from 165 to 175) due to lack of physical activity, and my 2014 season's goal has been to drop at least five of those pounds. To my pleasant surprise, within a few weeks I felt I was back in pretty good shape and was registering a post-ride blood pressure of around 115/63, with pulse rate still in the 55-65 range. I was surprised even more when my BP dropped to 105/60.

Last week, having rebuilt my biking speed and distance, I decided to stretch my ride to a hard-and-fast 25 miles. At the 20-mile mark, I discovered I had averaged 15 mph, which was my best-ever speed for what I considered a long ride, and I was so ecstatic, I phoned my wife and told her I felt able to ride another 20! She was horrified and insisted I take it easy on the last five miles of my planned route.

Of course, you know what I did --I tried to maintain my 15mph average over those 5 miles. But after less than a mile, my whole body turned against me. I was barely able to make the pedals go around. My muscles ached, I was gasping for breath, and I was ready to quit. Somehow, I managed those last miles and drove home.

I needed my wife's help to pull off my riding clothes, and she was so worried by the way I looked, she took my blood pressure. It was 96/60 with a PR of 49.

I spent the rest of the day like a zombie and went to bed early. But I felt better the next morning and went out just after daylight for my morning ride. Three miles later, I turned around and headed home, so exhausted again, I could barely make the return trip. That morning, my BP was 100/62; pulse rate 52.

My wife was so alarmed, she phoned the doctor, and he shifted his schedule in order to see me right away. He ordered blood tests, did an EKG (which showed my heart was okay) and told me to stop using one of my blood pressure meds (Spironolactone) and leave my bike parked for awhile. He theorized either I had a serious potassium deficiency relapse (which turned out not to be true), or my blood pressure was too low for the amount of exercise I was getting.

Since then, my BP has risen to about 135/77, which I'm told is a normal level for someone my age. Heart rate still ranges from 49 to 65. I'm feeling good again and ready to hit the bike trails, but my wife is threatening to put a lock on my bike unless I "rest" a few more days.

Needless to say, I have more doctor appointments and blood tests ahead, and since the first blood test revealed a potential kidney function problem, I also have to see a nephrologost.

So while I'm waiting and yearning for my freedom to be restored, does anyone have any ideas about that happened to me?

Don
Elkhart, In

It almost sounds like you bonked, what with the muscle aches and running out of gas. If you're riding harder and faster than usual, your body might need more fuel before and during the ride.

That is what it sounds like to me also. I would suggest trying a few sport gel packages for consumption during the next few rides. These gels are digested very quickly and are soon available to fuel the ride. They contain simple carbs that is rapidly converted to glycogen.

Those low BP numbers, combined with low HR, mean you can't get enough perfusion* to keep the body going during exercise.
When we exercise, our BP and HR both go up in order to meet the increased demands.
It is quite common for meds given for cardiac or blood pressure issues to interfere with that.


* Perfusion: The carrying of nutrients and O2 to the cells, and the removal of CO2 from them.

I also concur with the “you bonked” assessments.

However, you didn’t mention your “before ride eating procedure”, so it’s difficult to say with greater accuracy, but if you headed out without eating some kind of decent meal to provide the necessary energy for the ride distance per its elevated average speed (faster requires even greater expenditure), then bonking sounds like what happened to you.

Just as you must fuel a combustion engine, you must fuel your bio-engine or either will eventually run out of fuel and leave you stranded.

I'm in Shimagnolo's camp - I doubt very much that bonk is an issue for what is still a relatively short ride. Even if you're on a low-carb diet, you should have had enough energy stores to do the ride. That HR number is extremely low considering you were active at the time. An easy ride for me has me running at 115-130 bpm and although it may drop soon after getting off the bike, it's at 80 for a long time afterward. At 49, you were asphyxiating!

Bonk after an hour and 20 minutes though? It's not really enough time to burn through the glycogen. The meds, the heat, not enough water, not accustomed to the level of effort, it could be a lot of things IMO.

I had to quit one century with about 12,000 feet of climbing due to the same kind of symptoms. They took me to the ER where I had BP of about 90/49. My doctor now has me forgo BP meds before long/ hard rides. I am almost 72.

True, unless already low due to low calorie intake such that you're losing weight.

Nothing about his eating habits was conveyed!

What if he’s one of those individuals that doesn’t like to eat in the morning and just heads out on his ride? He is after all 75 years old and only 175 pounds (don’t believe he conveyed his height, but 175 pounds doesn’t even leave a bundle of fat reserves). If he headed out without eating, pushing as hard as he did to achieve his 15 MPH average speed, he could easily have burned off his reserve from the meal the night before.

My friend doesn’t like to eat when he gets up in the morning, then wondered why he bonked an hour or so into our ride (and we push hard on our rides). He’s since realized the importance of eating prior to heading out for a long distance ride, so now he eats before the ride, even if it’s in the morning, and he’s been fine ever since.

Until more info is provided about his eating habits, bonking cannot be dismissed.

Everybody is different. He's 75.

Last year I had to fuel a lot more then this year, or speeds dropped from slow to damn slow...

This year to date, nearly as many miles as all last year, I seem to need about 1/2 the fuel for given distance at a less slow pace.

TO OP

HOT DAMN!
YOU ROCK!

Too much too soon, not enough conditioning, and probably, not enough nutrient reserve.

The OP is on a variety of meds so there's no telling what his blood chemistry would otherwise be.

Bonking is very easy for diabetics or hard dieters, because there's very limited ability to maintain blood sugar levels as those are consumed faster than normal. Since the Op didn't mention any symptoms indicative of lactic acid, we'll assume that the heart and lungs are able to keep up the oxygen level, which is a good sign.

lastly there's the issue of electrolyte balance. No mention of hat, but it's easy to sweat a bit more than usual, and either not drink enough, or drink too much. Small changes in blood volume or electrolyte balance can bring on symptoms similar to bonk.

It's hard to say what is happening, but at 75, post bariatric surgury, and on all kinds of meds, it's very to throw something out of balance (possibly dangerously so), so the OP has to learn his limits, and be attuned to how his body is handling the load. Nothing wrong with pushing limits to increase speed or range, but if the OP is going to tickle the dragon's tail, he has to stay close to familiar ground.

I know what happened...if you're like me, you gave up your freedom when you got married!

I suggest you listen to your wife.

Thanks to everyone for the really great input. FbinNY makes some excellent points. As a (former) diabetic, I do have some difficulty maintaining blood sugar levels on rides, and I’ve learned to keep close tabs on that and carry remedies with me in the form of glucose tabs and high-protein/high carb bars. Typically, on a ride of 20-35 miles, I will have to wolf down one or two of the bars in order to keep my sugar from getting too low. My body is quite good in warning me about reaching that level, and since I’ve had a few scary episodes of dangerously low blood sugar, I pay attention to those warnings.

I intentionally do NOT take my blood pressure or irregular heartbeat meds prior to a ride, primarily because my after-ride BP level is always fairly low, and the heartbeat meds do tend to slow my heart rate.

Now, as for nutrition, I learned quite early on that I needed appropriate fuel prior to a morning ride, and through lots of trial and error, I’ve settled on this quite large (for me) breakfast: A poached egg on half an English muffin; a heavy slather of peanut butter on the other half; an envelope of instant oatmeal with whole milk and non-sugar sweetener, and a bottle of protein-rich Boost or similar shake.

Admittedly, as attuned as I am to my body’s ebbs and flows, I know zip about electrolyte balance, and I guess I’d better study up on it. The only time anyone has ever said anything to me about electrolytes has been the doctor’s office following my periodic blood work, and I’m always told my electrolytes are in balance, whatever that means.

From what you guys are saying, maybe I’m depending too much on my blood sugar level warning and should simply get into the habit of eating something like a power bar during the ride BEFORE I feel tired or hungry. CbadRider makes a good point: Maybe since I’m riding harder and faster than usual, I need more fuel while doing it.

I like Berner’s suggestion of gel packages. Never used them, but they sound just right for me if they are digested quickly. The bars I carry with me but seldom eat are Nature Valley Greek Yogurt Portein bars with blueberries & cranberries, some almonds & peanuts; 17 grams carb, 10 grams protein. I have to be a little careful because, in addition to my other issues, I came away from my surgery with a stomach ulcer.

Shimagnolo, the term “perfusion” is new to me, but I’ll definitely look it up and see what I can learn about the interference with it by cardiac/blood pressure meds. Thanks for the tip. It’s also something to talk with my doc about.

Good points, Gnosis. I’ve been eating the same basic breakfast before riding for the last two years, but what’s changed is I’m riding much harder and faster than ever before and also extending my ride periods and distances as well as taking more difficult routes. My egg-size stomach won’t hold any more pre-ride food, but it processes everything I eat very quickly, probably leaving me without any reserve to make up for the harder rides I’m taking.

BlazingPedals, the low HR has my docs totally baffled. At first they were alarmed and ran a bunch of tests without getting any definitive answers. They finally decided to cut my irregular heartbeat meds in half, and although I didn’t have any negative effects from that, the HR numbers increased only slightly.

Fastcarbon, I shudder to think what my BP would be if I took my meds before a ride!

Yankeetowner, you’re right. And of course, I listen to every word my wife says and do exactly as she requests........

The margin of error is much wider on the high side rather than low. So I suggest that you stay ahead of the game rather than reacting to low warning signs. Also marginally high sugar will have you feeling and riding better compared to operating at the minimum fuel level.

You might also get pointers and advice from the folks at Team 1, which is a pro bike racing team, all with diabetes.

As for all the rest, stay on the safe side with hydration and electrolytes, and push yourself beyond your limits, but only by degrees. Think like a mouse who'll venture out, but always within a quick dash to cover.

Well, I’m back in the saddle!

After a week off and reading the suggestions and tips from you guys, I returned to the bike path today, fired up and raring to ride. First, I had to convince my bride of 55 years I wouldn’t overdo it. Just 10 or 12 miles, I promised her. Moderate speed. No racing with any 30somethings. Ate a good, protein-rich lunch and purposely didn’t take any meds.

I did the 12 moderate miles easily, not even breathing hard. No low-sugar reaction, but I ate a power bar anyway during the last 3 miles.

As I approached my car, I thought about what FbinNY said about tickling the dragon’s tail. I chuckled to myself and rode right past the parking lot and onto a stretch of bikeway that climbed up a long hill, went under a highway overpass, then through a tree-shrouded section of farm country that was picture-postcard perfect.

The bike path ended at a heavily traveled section of county road that I had ridden dozens of times, including a week earlier when I had my collapse. I thought about it but then turned around and rode back to my car, finishing with just over twice as many miles as I promised my wife I’d ride.

I felt good!

At home a few minutes later, my blood pressure was a very reasonable 129/68. And heart rate was (for me) a remarkable 70!

My child bride isn’t home, so I don’t have any Ricky Ricardo-type ‘splainin’ to do. Yet.

And yeah, I’ve got a smile on my face. Now about that perfusion....

Like yourself RV writer I have been married a long time. When it comes to doing thing that can be percieved as less than brilliant, I have found it better to not share that info with my bride untill a long time has passed. Some thing about 2 weeks after my death.

Baboo

Baboo, not only is your comment very funny, but it is also quite profound, accurate, insightful and great advice to any young man who is contemplating the institution of matrimony.

I"ve had two recent instances of doing 60 miles, feeling OK, taking an hour nap and waking up dead. Well, not dead, but very draggy. In both cases I measured my BP and it was around 95/60. I ate some salty stuff and got some electrolytes, and felt fine after an hour. Can't say for sure it was the lytes, of course.

Are you on any rate-limiting medications like β-blockers (e.g. metoprolol, atenolol, etc.)? It sounds like you got dehydrated but your heart did not (could not?) speed up sufficiently to maintain a decent cardiac output.

The heart rate of 49 is the key. Ain't a normal response. Several posters have pointed out some potential causes. There are quite a few more. Make sure your doc knows that detail.

JohnDThompson: I am, in fact, taking the Beta-blocker Carvedilol for cardiac arrythemia (irregular heartbeat).

I appreciate your concern regarding this issue, but it’s an area with which I am quite familiar, unfortunately. Carvedilol has a wide range of unpleasant side-effects that I’ve learned to live with for the last 40 years in order to ensure that my fluttering heart doesn’t result in a stroke.

For example, the meds are at least partly responsible for sleep disorders such as apnea, insomnia and nightmares. I won’t go into how I deal with those except to say that I dread bedtimes the way most people dread visits to the dentist.

Sleep disturbances aside, Carvedilol lowers my body’s plasma glucose and stimulates hepatic glycogen breakdowns, leading to potentially deadly hypoglycemia (very low blood sugar). The drug’s natural tendency to do that is exaggerated by physical activity (such as bike riding) without appropriate carb fuels (digested food, in other words). For me as a (former) diabetic, each bike outing is a balancing act of trying to ingest enough food into my egg-size stomach without either throwing it up or gong into low blood sugar shock. If I make myself sick by over-eating or eating the wrong things (solid meat, for example), I’ll spend from two to six hours in the bathroom and not be able to ride anywhere. If I don’t eat enough and fail to refuel while riding and/or immediately afterward, I could end up in the hospital or the morgue.

It’s an unpleasant game I play with my body every day, but it’s a game I believe is absolutely necessary in order to maintain my muscle tone, fitness and weight (currently 175 – about 7 pounds above my maintenance weight).

Dehydration is a potential side effect of Carvedilol but is much less likely than with other B-blockers. It is definitely not a problem for me. On the other hand, there is no doubt Carvedilol causes edema (fluid accumulation) in my legs, and biking lessens that somewhat.

As I mentioned earlier, my doctors believe Carvedilol might be responsible in part for my low heart rate, but although dosages have been changed and tweaked over the last couple of years, there’s been no significant change in my HR, no matter whether I’m bike riding or spending all my waking hours behind my computer.

Dudelsack: My docs (including my cardiologist) are very much aware of my low HR. They’ve had me do the treadmill/ekg routine several times and tell me that my treadmill-HR is just slightly below normal, but my at-rest HR, while a little alarming, appears to be normal for me currently.

I really appreciate everyone's thoughtful comments.