A friend of mine has suggested in our conversations about exercise that I "cheat" while cycling. His belief, which I believe is uncorrect, is that when I ride a bike for exercise and I coast a little bit here and there that I'm no longer exercising/burning calories, thus I'm technically cheating. He says when he walks for 3 miles he has to keep moving. If he stops walking he can't coast and is no longer moving forward therefor there is no cheating.

I've kinda tried to explain to him that because of Newton's Laws Of Motion that every action has an equal and opposite reaction. Thus if I am indeed coasting on flat ground, I've already applied the effort to the pedals and burned the calories to propel the bike forward. Thus my stance is coasting is not cheating in regard to exercise.

Does anyone know the math for this or have a formula? I'm curious to know who is right, but my guess is I am.

EDIT: I meant to post this in the General Discussion area, so please feel free to move it there.

Also, when my friends says "cheating" I'm fairly sure he means "no longer burning calories" and not breaking some type of rule.

Once you get up to speed, there are a myriad of forces that conspire to slow you down. A body in motion stays motion only in a vacuum. Thus, you have to input energy to maintain a constant speed. Also, you may not be expending much energy on a descent, but you probably put in more effort on an ascent than a typical walker does during a three mile walk. Road cycling is not about maintaining a constant effort, it's more about the total energy output.

Cheating is a poor word choice here. So is uncorrect.

Well...it would seem to me that the math wouldn't be hard at all. But getting numbers to do the math with would be a pain. You'd need to know things like how much force you applied to your pedal for how long in order to get such and such a distance. And you'd need numbers for how much force your friend applied to the ground in order to get so much distance.

It's hard to imagine that it would be worth the trouble. And I'll bet your friend knows this, too. He's probably just making an unprovable claim in order to bait you.

The next time he gives you a load like this just tell him, "Bicyclists are happier than walkers". If he disputes this, just keep on saying it.

Well, there is a way to observe the results of pedaling vs coasting although it does not quantify well. Pedal your route with your usual coasting. Now pedal the same route in the same time (in the same wind) on a fix gear. I promise you will find it a lot harder. Terrain and wind have a lot to do with how much. Truly flat, even terrain in no wind are very close. HIlly windy rides are much harder.

I have for years used the ratio 4/3 to express how much harder fix gears are than gears averaged over all conditions. (4 miles of geared riding = 3 miles of fix gear riding.) Now part of that is obviously that the fix gear isn't always the "right" gear for the conditions. But the fact that you never coast (or "cheat") takes its toll. In my racing days, in stormy, wet weather I would take out my fix gear, ride to a town 50 miles upwind, stop for lunch and fly home. But that flight home was hard!

My miles geared and fixed are roughly 50-50 so I have developed a pretty good idea of the toll always pedaling takes. Try riding fixed some day. You might find it is significantly harder. And you might develop an appreciation of how much easier being able to coast is.

Ben

I'm going to skip the math, not because I can't do it but because it's not necessary to prove your case. When your friend walks, he uses various muscles as his stride proceeds. At intervals, each of those muscles has cycles of flexing and rest. Same for your pedalling. So, each activity "cheats" by your friend's definition.

Now, about that coasting: sure, you've broken the rhythm. But you are likely also doing something else. For example, when you descend at speed you may be expending quite a bit of energy holding a tuck or dealing with the steering around that skunk carcass in the curve. Even when you're lolly-gagging on the flats you may bend down and get your water bottle. Every movement does some chemical work (and some of them do physical work too).

For the same power level, your friend is right, all-cruise will get you there sooner and spend more energy than cruise-and-coast, because you are making cruise power only part of the way instead of all the way.

Yeah, is there seriously any doubt that you'd do more work by constantly pedaling? The amount more would depend on the power at which you pedal, but it would be more no matter
what.

You're probably burning more calories than him and pedal then coast burns even more than travelling at a steady speed, assuming you end up with the same average speed! Why? Because the amount of energy needed to achieve a speed is proportional to the cube of your speed because of air resistance. So say you pedal up to 15 miles and hour and coast down to 10 miles an hour, so you end up with an average speed of around 12.5mph. The bit where you exceed 12.5mph uses more energy than the bit where you are below 12.5mph. They don't add up to the same energy compared to a steady speed of 12.5mph they add up to more, because it takes more energy to get to 15mph from 12.5mph.

When you stop pedaling, it's the same as him stop walking. Whether you are burning more calories per minute than him when both of you are exerting is a different story. It doesn't take a physics major to understand that.

Get a fixie. Are you still pedalling if the pedals are dragging your feet around?

Just tell your friend, walking is for people that cannot ride a bike.

Assuming your friend is not as obtuse as he sounds and simply having a little fun trying to bait you correct?
if so, just challenge him to a very simple contest.
You walk three miles with him and he rides three miles with you.
Assuming you are an avid cyclist as you post here frequently I am guessing he will not be able to stay anywhere near you on a bike but you will match him step for step on a walk.
Once that happens you then ask him how you can be in better shape than him if you are cheating

It all depends on how much power you put to the pedals. You could easily burn fewer calories by constantly pedaling, by simply not pedaling as hard.

What matters is how much work you do. That's determined by the time, distance, elevation change, and speed.

If you cover the same distance, over the same terrain (assuming same bike, and same position on the bike) you do essentially the same amount of work, whether you constantly pedal, or pedal and coast.

In fact, it's possible to burn more calories pedaling then coasting, to the extent you increase your speed when you pedal, and let it drop while you coast. The squared increase in wind resistance with the increase in speed, will result in an increase in the total work for the same distance over the same time.

Air resistance is proportional to speed squared, not cubed.

Your friend would be better off stating that walking is superior to cycling because when walking you have to support your body weight whereas when cycling you are in a seated position. Regardless, the calorie burn from cycling is far higher than walking, whether you pedal & coast or pedal continuously. And what if you didn't coast? What if you did intervals & went at your max for 5 minutes and then recovered by pedaling lightly for 1 minute, rinse & repeat... are you still cheating? I prefer to pedal continuously as it's flat where I live but I still vary the cadence & power so I am constantly either tiring myself or recovering.

The bicycle is still, for all intents and purposes, one of the most (if not the most) efficient modes of human-powered transportation.

Walking is a fight against gravity, in which you're constantly falling forward and catching yourself with a forward foot. Rolling through, you transfer that to forward momentum.

From a subjective point of view, cycling is more fun.

Yes, correct...I was assuming that the OP, in stating they ride for exercise and coast "a little bit here and there," is not out noodling about, is putting in a good effort, and would continue to make that effort level if they subbed pedaling for coasting, but those assumptions aside, your point is well-taken.

I'd bet money, though, if we put a power meter on the OP's bike and had them ride their regular way and then had them make the effort to pedal continuously, we'd see a net increase in work/calories.

If you ride at a casual pace with lots of coasting, say around 12 mph, you'll burn about the same calories per hour as walking at 5 mph (a super-fast pace). Any faster on the bike, or slower walk, then cycling wins for calories per hour.

I ride lots of road miles fixed.

Pedaling constantly gives you a better workout, developing muscles better. Pedal-then-coast keeps you from getting in as good a workout in in the same amount of time...whether you get to your destination faster or not.

Most people want a good workout when they ride.

Ergo, keep pedaling. It is one thing if you're on a hilly century and spent and letting gravity do your work on the downhills, quite another if you're on a 20 miler and coasting on flats. Best way to see exactly how guilty you are of not getting good workouts in, look on Garmin Connect at the graph of cadence....if the graph looks like a rack-gear on your car, it means your endurance is getting short-changed. Odds are you're short changing yourself by coasting a TON more than you think you are.

Sure, when you're coasting you're not expending much energy, and when riding a hilly route one tends to coast more than a flat one. However, a two-hour ride on a hilly route with more coasting felt about the same as a four-hour ride on a relatively flat route with much, much less coasting effort wise, and in how-I-felt-the-rest-of-the-day wise.

So if I pedal constantly, keeping a speed of 12mph, will I get a better workout than if I pedal up to 30mph, hold for a minute, then coast until I am back to 15mph and repeat, both for the same amount of time? One should be careful when making definitive statements.

There is no correct answer because the question is wrong. Or better put, question is not well enough defined.

I think your friend is just jealous because he is not a cyclist, so let him have his delusion that you are "cheating."

Thing is...90% of people I see pedaling and then coasting are not doing intervals, which is what you describe. If they are doing intervals they do not post on cycling forums calling the activity "pedaling then coasting", rather they call it what it is-"intervals". Most people pedaling and then coasting are not doing training intervals. Most are turning 12-15MPH and then stop pedaling, and only continuing pedaling once their speed drops more than their liking. It is a bad habit to get into, that is easily suckered in if you do lots of MUT riding.

Definitive, sure? But not careless, rather reasoned. You can read a fair deal by how people phrase things.

I agree it is a bad habit. Mostly because accelerating is very energy consuming, so keeping a constant speed/effort is a more efficient way of pedaling.