Big Dogs Can’t Run — Training and Riding Tips for Bigger Athletes


By Steve Chambers — A popular t-shirt slogan a few years ago read “If you can’t run with the big dogs, stay on the porch”. The sad truth is big dogs can’t run with the pack. I should know; I’m a big dog, a/k/a a Clydesdale.

“Clydesdale” generally means over 200 lbs. for men and over 150 lbs. for women. Female Clydesdales are often called Fillies, Athenas or Amazons. For this article, I’ll refer to both men and women as Clydesdales.

Steve Chambers at the Cache Valley Century Ride. Photo courtesy Steve Chambers
Steve Chambers at the Cache Valley Century Ride. Photo courtesy Steve Chambers

I wasn’t always a Clydesdale. In high school I was too small to play football. But I made up for it by being slow. I was always at the back of the team running laps. Once, a coach, probably trying to speed things up, kindly told me that it was shorter to run around the inside of the track. I got bigger but I didn’t get faster.

In the 1980s, I discovered triathlons. At that time, I could run a steady nine-minute mile. Years and pounds have raised that to about 12 minutes. With some technique improvement and additional weight loss, I can improve, but probably not to what most people would consider normal mile splits. After a race, I tell people I flew through the course, passing rocks and trees like they were standing still. Forget about running with the pack; we’re lucky to see the pack after the first mile or so.

Why We’re Slow

So are Clydesdales just fat and lazy? A little more discipline, a little more effort, we’d be right up there with the so-called normal people, right? Wrong. Like a moving van differs from a sports car, Clydesdales aren’t built like their smaller brethren.

From high school physics, you might recall the formula for kinetic energy (the energy of movement): E = l/2mv2, where m = mass (weight) and v = velocity, (speed). What this says is that for a person to double his or her speed requires four times more energy. So for 250 lb. runner to drop from a twelve to a six-minute mile to keep up with a 125 lb. runner, he needs EIGHT TIMES more energy than the 125 lb. runner requires to run a 12-minute mile, twice as much for the size difference and four times as much for the speed differential.

But the real problem is VO2 max. This is the rate at which the body utilizes oxygen, which is necessary to convert its stored fuel into energy. As body mass increases, relative VO2 max actually decreases.

Here’s how Stephen Seiler, PhD in exercise physiology, explains it: If you take a highly trained 5’7″, 140 lb. cyclist and add 12% to his height, he will be just over 6’3′ tall. If you then configure this new, taller athlete proportionately to the original athlete, he will weigh 195 lbs. His absolute VO2 max will increase from 5.0 liters/minute to 6.25 liters/minute due to the increased heart volume. This should make a more efficient and therefore faster athlete. But because of the increased body mass, the relative VO2 max will actually decrease 9%. So while the athlete is now bigger, has more mass and therefore requires more energy to be competitive, his ability to utilize energy has decreased. It’s as if someone took the pistons out of a couple of cylinders in the engine at the same time they loaded up the trunk.

This is why there are very few large, competitive endurance athletes. Chris Froome and Romaine Bardet are almost identical. Both stand 6’1” tall but only weigh 149 and 148 lbs. respectively. Nairo Quintana stands 5’5” and weighs 128 lbs.

Clydesdales redline at very low speeds. When we try to crank up the velocity, our muscles send a signal to the brain that they need more energy. The brain orders the heart and lungs to deliver more oxygen so glycogen can be burned. Because the body has a low relative VO2max, the heart tries to compensate by beating faster to deliver more oxygen. This quickly pushes the athlete into the anaerobic area. Most trained endurance athletes have an anaerobic threshold of 75%-90% MHR. As soon as you exceed your anaerobic threshold, the effects of lactic acid begin to set in and you can’t sustain the pace.

Filling the Tank and Cooling the Engine

Clydesdales face a host of problems the Greyhounds don’t. Because our energy needs are greater, we have to carry more food and water in long races. Many times we come to an aid station long after the rest of the pack has left to find empty water cups, black banana peels, and little else. Our slower speed makes long rides really, really long.

Those of us who choose to ride centuries, run marathons or do Ironman-distance triathlons become creative in our training. Routes are planned to pass by convenience stores. We stash food along the way like through-hikers on the Appalachian Trail. Because of overheating, we train early in the morning or late at night, wearing headlamps and carrying flashlights. Sometimes we even break up long sessions over two days. For Clydesdales, every run is a marathon, every marathon is an ultra, and an ultra may be impossible.

Heat poses special problems for Clydesdales. Not only is staying cool more difficult, but due to the extra time we spend on the roads in the sun, we’re more prone to hyponatremia, low blood sodium due to excessive sweating. It’s crucial for Clydesdales to drink electrolyte replacement drinks during long training sessions, not just water.

The key to being successful (and by that I mean completing) in long distance events, besides the proper training that all athletes have to undertake, is fueling. Think of the glycogen in your muscles (the energy your body will draw on during a race) as a box of matches. There are only so many matches in the box; when they’re gone, you stop. You can’t will yourself to finish when the glycogen is gone any more than you can will a jet liner to stay airborne when the fuel tank is empty.

You can delay using up all the matches by fueling during the event, but you can never replace calories as quickly as you use them. The best you can do is time it so you run out of calories as you cross the finish line. A Clydesdale might burn 1,300 or more Calories per hour during a long race. Considering that glycogen stores in the muscles and liver probably can’t exceed 2,000 Calories, there is at most energy for less than two hours. Remember that it takes 30 minutes or so for whatever you eat to get to the bloodstream, so you need to start eating 60-90 minutes after you begin exercising.

The body can’t convert more than 250-280 Calories of intake per hour into usable energy. Anything above that amount will slop around in your stomach, eventually causing gastric distress. Most people who become ill during a race do so because of overeating, not over-exerting.

Know Your Limitations

I’ve learned that for rides up to an hour in length, I’m usually safe without taking any food, as long as I took in 350-400 Calories before I started. Over an hour, I need to eat something. During your training, keep track of what you eat, when, and how you feel, then plan race day accordingly.

Try out different fueling strategies before race day. Don’t ever use a new energy product from your goodie bag that you get at check-in during the race. Save it for a training ride. Find out what works for you and stick with it.

Expect Something to Happen

Preparing for my first Spudman, I had my fueling strategy all worked out — when I would start to eat and drink, how much, how often. On the swim, I swallowed about half of the Snake River and didn’t feel like eating or drinking until the turnaround on the bike. By the time I ate and drank, it was too late and I bonked on the run. My plan was fine if I had been able to stay with it. But things happen in a race. When it happens, deal with it; don’t let it ruin your race.

Take Charge of Your Life

No race day strategy can overcome a poor nutritional foundation. Here again Clydesdales face problems unknown to others. Most of us are trying to lose weight, and we might be tempted to try various diets, especially the low-carbohydrate ones That’s a big mistake. Those diets are designed for the average American who leads a sedentary lifestyle. Athletes need fuel and fuel comes mainly from carbohydrates.

Many Clydesdales have health issues associated with our size. I ride not to win but because cycling gives me the motivation I need to keep exercising, and I exercise because I have three of the four markers for heart disease. If I weren’t active, a low-carb diet would be ideal for me. But I am active, I need extra carbohydrates those diets don’t provide. The problem is, how to get the fuel I need and still maintain the blood chemistry my doctor advises.

Find out what’s going on inside your own body. Educate yourself. There are dozens of books about nutrition for endurance athletes. The American Diabetes Association has some excellent recipes and meal plans if you’re facing diabetes, like millions of middle-age Americans are.

Don’t Give Up

Carry your Clydesdale frame with pride. If it takes you two and a half hours to finish a sprint triathlon, that’s no less an accomplishment than a 2:30 marathon for a skinny runner. If you don’t want to commit to training for century rides, marathons or even Olympic-distance triathlons, focus on shorter events. Whatever you do, Big Dog, get off the porch.


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  1. Thanks Steve! Nice to hear some advice for us big dogs! I’m 6’5″ and over 300 lbs but have been riding centuries in the summer for the past 4 years – some better than others, but I’ve completed them all so that is a success. I do well when I ride with “normals” that are out of shape – hah! My favorite line – “I’ll catch up to you on the downhill.” I’ve had my fair share of bonking so I appreciate your advice on food.

    A couple of things I’d add to your observations: equipment choices and failures. I’m an amateur mechanic because I have to be – I can replace spokes, bottom brackets, chains, cogs, and true wheels out of necessity. While the Clydesdales might be slower, we are likely putting much more power on the bike and stressing components out more than the normals – I’ve broken cranks and chains and wheels and burn through cheap Shimano bottom brackets in a single season. I’m finding slightly wider tires are much more comfortable and they make me more likely to ride. I’m also considering buying a bike specifically for Clydesdales from Zinn Cycles. I’m less worried about bike and component weight and finding myself more focused on maintaining power and strength and cardio fitness and just staying on the road. Finding bike clothes that fit is also a bit of a laugh – the last two years the largest jersey at the Cache Gran Fondo just wasn’t going to happen. This year I’ve lost a few pounds and hope to squeeze into the xxl…

    Thanks again Steve – any Clydes in or visiting Cache Valley, I’d be happy to take you out on a ride.

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