QUESTION: I have been riding on and off for about 35 years. I am 54 now. My problem is I frequently “bonk” after about an hour. It doesn’t seem to matter if I am doing moderate or higher intensity ride. I can do 20 miles flat riding at about 15 MPH, my heart rate stays above 150 the whole time, after about an hour I just run out of gas.
I drink Gatorade and eat small snacks every 30 minutes or so. Sometimes I find a second wind. Sometimes I just crawl (metaphorically) back to the car. I always recover quickly. About an hour after a ride my heart rate is 70 or so. My resting HR is about 60. What can I do or increase my endurance and be able to ride 75 plus miles without bonking. I have the right gears and my position on my bike is pretty good, I am not a newbie. Just trying to get to where I was 20 years ago. – Brian W
ANSWER: Do you have any issues with low blood sugar when you are not riding your bike, or when doing any other types of exercise like hiking or long walks?
Most cyclists should be able to complete a ride of up to an hour without necessarily needing any calories at all. So if you are experiencing any other types of low blood sugar issues off the bike, my first recommendation is to see your doctor and make sure you don’t have an underlying issue such as Type 2 diabetes or some other type of insulin resistance.
Assuming no underlying blood sugar issues, I might suggest a counterintuitive idea. Might it be possible that you are triggering the bonks by consuming particularly high carb, sugary drinks like Gatorade and snacks that your body is overcompensating and trying to get your blood sugar back down just as you are exercising, causing a bonk?
How about trying to eat solid, regular food (like a meal) a couple of hours before your ride so that your glycogen stores are topped off, and ride the first 45 minutes to an hour with just water and then begin fueling? Additionally, you might try switching to an energy bar with water instead of Gatorade, to prevent a blood sugar spike from the liquid calories that could be followed by a bonk.
Kevin Kolodziejski recently wrote a column about his experience bonking after a sugar spike from eating a more highly processed food than he was accustomed to eating before his ride.
Two other articles about fueling — one from a retailer that sells endurance nutrition products, and another one from a manufacturer that makes it — have some decent tips about fueling for a ride.
The Feed writes,
A few years ago, I was about to start a 130-mile ride down the coast of California as part of multi-day San Francisco to San Diego charity event. For many of the participants, this was a daunting athletic challenge. At the start –at 6 am I might add– I saw a number of people tear into and devour a Gel…
This is actually the moment that I decided that I needed to start The Feed. That I could share my knowledge and help people with how to use performance nutrition, like Gels and Chews to their advantage, not their detriment.
The folks I saw devouring the gels and chews were going to be in for a rough day. They were now spiking their sugar levels and there was no way they could now consume enough chews and gels, aka Quick Energy, to sustain themselves for the next 8 to 10 hours of riding. The result I predicted (and came true) was that they had a significant energy crash after the first few hours and really struggled to finish the ride.
And Hammerhead Nutrition writes,
Yes, the body needs your assistance in replenishing what it loses, but that donation must be in amounts that cooperate with normal body mechanisms, not in amounts that override them. Here’s an important fact to keep in mind: at an easy aerobic pace, the metabolic rate increases 1200-2000% over the sedentary state. As a result, the body goes into survival mode, where blood volume is routed to working muscles, fluids are used for evaporative cooling mechanisms, and oxygen is routed to the brain, heart, and other internal organisms. With all of this going on, your body isn’t terribly interested in handling large quantities of calories, fluids, and electrolytes; its priorities lie elsewhere.
Your body already knows it is unable to immediately replenish calories, fluids, and electrolytes at the same rate it uses/loses them, and it has the ability to effectively deal with this issue. That’s why we don’t recommend trying to replace hourly losses of calories, fluids, and electrolytes with loss amounts. Instead, we recommend smaller replenishment amounts that cooperate with normal body mechanisms.
When even the guys who make and sell endurance fuel are telling us this, there might be something to it.
Readers, what is your perspective on this? How have you overcome bonking issues?