"The" Question: Does running 10 miles at an easy intensity burn the same calories as 10 miles at a hard pace?

When measured directly the calories burned per mile at various speeds is not exactly the same but it's close enough not to matter.

If you are 150lb you will burn 113 calories per mile at 12mph and 104 calories per mile at 10mph. So that's a 1:00 per mile pace difference and about 100 calories over 10 miles.

Alan

Runningart2004 wrote:

When measured directly the calories burned per mile at various speeds is not exactly the same but it's close enough not to matter.

If you are 150lb you will burn 113 calories per mile at 12mph and 104 calories per mile at 10mph. So that's a 1:00 per mile pace difference and about 100 calories over 10 miles.

Alan

Interesting, but where did you get that information from? Do you have a link?

Here's my take on it.

(1) Higher speeds have much greater inefficiency therefore greater energy cost. What uses more gas, traveling 20 miles at 110 MPH or 55MPH. Yes you are on the road longer at 55MPH but you still use less gas.

(2) After the faster run you remain heated longer, continue to sweat, heart rate stays increased longer all that consumes energy. After you stop running you continue to use energy longer after the fast run.

(3) Even well after a fast hard run your system is taxed to a greater degree, there is muscle break down, it takes more energy to repair and recoup from a hard fast run than a longer slow run.

Another Option wrote:

Which is more efficient - walking, jogging, or running? Depends on each person's biomechanics; though, I suspect that walking is most efficient since it has the least amount vertical displacement per mile and jogging is the least efficicent since it has the most vertical displacement. At sufficiently high speeds the energy consumed by drag overtakes the difference due to vertical displacements per mile and running becomes less efficient than jogging.

Walking is less efficient than running because at least one foot is on the ground 100% of the time, at times both. (That's the definition of walking, if both feet are airborne at one point during each step-cycle, it's running.) Feet on the ground is energy loss due to friction.

To get an idea how much energy is loss due to friction while walking, put on a pair of in-line skates, see how far you can roll on flat ground with one push of a leg using the same effort, F Force, as pushing off while walking. You roll to a stop due to friction between wheels and ground and friction of the wheel bearings. How many steps N do you have to take to cover that same distance, that's N x F necessary force to over come friction.

Lenny Leonard wrote:

Fitness Diet wrote:

There is a misconception that lower intensity exercise, such as jogging and walking, burns more fat. It burns a higher percentage of fat in comparison to carbohydrates, but higher intensity workouts will still burn more calories and with it, more fat.

Example:

30 minutes of low intensity exercise:

240 total calories burned: 96 fat = 41% fat, 59% carbs

30 minutes of high intensity exercise:

450 total calories burned: 108 fat = 24% fat, 76% carbs

The poster who mentioned intervals and higher intensity exercise is best when wanting to lose weight is correct.

Loss of lean muscle mass will decrease the resting metabolic rate, making exercise including resistance training important.

youre still not specifying what is high and what is low intensity.

I (and I think the OP) want to know: do I burn more calories running 10 miles in 60 minutes or 10 miles in 80 minutes?

Think Maximum Heart Rate (MHR). . As your heart rate increases, so does your respiratory exchange rate (RER). The latter determines how many fat vs. carb calories you burn. The higher the RER, the more carbs you burn. Low intensity, you could be around 60% MHR. High intensity around 80% MHR. MHR depends on the person, age, fitness level, etc. Now how long you can hold your MHR is another matter.

If you're exercising over equal time, of course high intensity will lead to more calories burned vs. low intensity. If you're talking the same distance (10 miles) at different intensities, that is a bit different. You're going to be running for a longer time at a lower intensity. Example: if you ran 10 miles at 6:30 minute/mile vs. 8:00/mile, that's 15 minutes less time running. However, I suspect that you would still burn more calories at the faster tempo. I don't think that extra 15 minutes is going to be worth that many more calories.

I have limited knowledge in the subject, but I suspect this is why you see somewhat overweight people finishing these half marathons in 3 hours, marathons in 5+ hours, etc. My guess is they have fairly decent resting heart rates, but because they do little more than slow runs and no real fast running that would increase their heart rate, they aren't losing more weight. My theory any way.

I suspect that the energy systems in play probably impact calorie expenditure. If your lactic threshold for 6:00 pace is somewhere around 10 miles, then 10 miles at 7:00 pace won't burn more than 10 miles at 8:00 pace, but 10 miles at 6:00 pace will burn more than 10 miles at 7:00. And if for that same example if your threshold for 5:30 pace is maybe 5 miles, then running 5 miles at 6:00 won't burn more than 5 miles at 7:00 but running 5 miles at 5:30 will burn more than running 5 miles at 6:00. So there's an interaction of pace, distance, and energy system (aerobic vs. anaerobic) and probably muscle glycogen state (ie. you may burn different amounts of energy when puling from stored muscle glycogen vs. when trying to break down body fat into fuel).

I'm not stating this as fact, or even opinion; this is speculation.

drag out some equations.

Work =Fdxcos theta.

10 miles/same distance. Is the force the same--differs in acceleration phase at the least

Kinetic Energy=1/2 mv^2.

10 mph gives a lot more kinetic energy than 7.5 mph, but then how much energy is expended in maintaining this pace vs. accelerating to it? And then you are holding the pace for only 60 minutes vs. 80 minutes (but same distance).

Don't forget wind resistance, which is substantially greater at 10 than 7.5 mph.

One more common sense point supporting #3. Think about how you feel for the rest of the day or even the next day after a very hard 10 mile race. Now compare that with how you feel after an easy 10 mile run.No comparison. Which is using more energy? Easy answer.

I've looked into this before and Alan is correct in terms of calories ex poo ended DURING the exercise. At the range of normal running intensities the difference in calories burnt is negligible (due, in part, to the fact that wind resistance is relatively insignificant at, say, 7-15 mph compared with a car at 55mph).

People I've talked about this with before get confused with the miles/time thing. The long and short of it is that a mile is a mile at whatever pace and has the same energy cost. If you do it slower you expend energy at a slower rate per MINUTE but do so for a longer time.

If you have a fixed amount of TIME to train then a higher intensity workout will obviously require more energy.

As far as the question of energy expended after the workout is concerned I can't offer anything more other than the common anecdotal evidence of feeling more tired for longer after a hard effort seems to logically suggest that the energy requirements for the body to recover are greater.

You do have to deduct your resting metabolic rate, otherwise everything gets screwed up because the slower you go, the longer you're out there.

The main factor that changes energy cost is the aerobic/anaerobic breakdown of the exercise. Anaerobic metabolism is very, very inefficient, so when you get up to around tempo pace, there's a non-negligible (from a scientific standpoint) difference in your calorie expenditure. That said, you're not going at those paces for very long, and the difference in calorie expenditure isn't big enough to matter for purposes of diet planning.

You will expend more kcal running at a greater intensity. Theoretically, if you are using 100% fat as a fuel source, you will expend 4.7 kcal per liter of oxygen consumed. That would be a resting condition, since you use mostly lipid as a fuel at rest. If you are using close to 100% carbohydrate as a fuel source, you will expend 5.05 kcal per liter of oxygen consumed. That would be maximum effort, since most people use almost 100% carbohydrate as an energy source at maximum effort (perhaps less if they follow a ketogenic diet). You can find these data in any physiology text.

So, if you are running at intensities in between these efforts, the kcal per liter of oxygen value will change. Not much difference between 4.7 and 5.05, so the common average value used is "5 kcal per L of oxygen" when you want to calculate kcal expenditure, regardless of speed/intensity. But, yes- you will expend more kcal if you run the same distance at a higher speed/intensity. Not only will you consume more oxygen, but you will expend more kcal per liter of the oxygen consumed. The difference might seem negligible at distances of, say, 5K, but over a marathon, the difference might be relevant for some people.

Exactly. You burn more calories when you run faster because a 60 minute run at 6 minute mile pace covers more distance than a 60 minute run at 7 minute mile pace. There may be some small increase in per mile energy expenditure as speed increases, but mostly you're burning more calories because you're running farther in a given amount of time.

After burn is also relevant, but probably less so for distance running than interval training. Probably not much difference between running two miles at 7:30 pace versus running two miles at 8:30 pace, but I'd guess that a hard 8X400m repeat workout would ultimately result in much higher calorie expenditure.

lol lol lol lol wrote:

No. The difference is modest, but it does exist.

"why are elite runners or just people who run fast all the time so much leaner than ultra runners?"

I assume--if this is true, and the ultra events don't involve dealing with extreme cold--that ultra events simply are not that competitive, **yet**, and it is possible to reach the top without achieving the extreme levels of conditioning--including very low body fat percentages--of top distance runners in the 5000, 10000, etc.

Elite runners - who do intervals - are leaner than ultra runners who tend to do little to no intervals at all (at least anything 1000m). Interval training burns fat. Look it up.

Read Tim Noakes book *Lore of Running* where there is a detailed formula for calories burned paced on pace. If i recall correctly there is approximately a 5% extra calorie burn running 1 mile near mile race pace compared to 1 mile at an easy jog.

Wind resistance is a key factor (it's a square function, a 10mph wind has 4X the resistance as 5mph wind). Also systems (human bodies, engines etc) become less efficient (require more energy/burn-more-calories) near maximum loads.

There is also post exercise calorie burn, which will be greater at higher intensities.

How can you run 10 miles near mile race pace? 10Xmile. Even running 5-10k race pace will have slightly greater burn/mile then an easy jog.

Also, consider this: If you run 10 miles @ 6 min. pace your total TIME running will be 60 minutes, but if you run @ 9 min. pace your total time running will be 90 minutes. So you will be burning less calories/minute but for a longer duration of time. IMO it's a wash because the duration increases the slower you run.

When I was out injured I would walk the same course I ran daily. It took twice as long, but I did not gain any weight, probably because of the longer duration.

Yes, they burn very similar amounts. Because the slower you go, the longer it takes. You may not be burning them at the same rate as a fast pace, but there is extra time added allowing you to burn some extra.

Ultra joggers typically walk most of the course, except elites....Chris Vargo is pretty skinny, man.As well, ultra joggers drink tons of stupid IPAs as "recovery" and also tend to believe in dietary myths and trends like Paleo and "fat adaptation."

burningbridessuck wrote:

Confused, people say that is true but then why are elite runners or just people who run fast all the time so much leaner than ultra runners? It isn't diet since I've seen elites each some bad diets

The only thing this thread proves definitively that letsrunners suck at physics.

The only one with any sense on this thread is Alan. No way you can get a reasonable conclusion starting from basic principles. The act is too complex. Good physics runs from the empirical to the abstract but almost everyone on this thread is running their reasoning backwards.

Insults out of the way, A few points:

1. In the work equation the distance is constant but why would we assume the same force is applied at different speeds?

2. The increased effort of running faster is related to increased power demands not energy demands. Of course running faster requires more power -- whether it requires more energy is a question of efficiencies not effort.

3. The question of whether energy is used during or after the run is irrelevant... Here the physics is absolutely clear. The body can be treated as a mechanical system. But even then just as a motor vehicle has efficient velocities and inefficient velocities due to hearing there should be some variation from runner to runner.

4. All things considered the differences in energy efficiencies at different speeds should be very slight compared to the work done in moving the body over 10 miles. For that reason the fact that running at 8 minute miles vs 6 minute miles ought not be too different in terms of total energy requirements. However, the POWER requirements are totally different and that's the main thing in running.

Actually, "The" question is will jarmin ever get laid?

There is a simple mathematical formula that calculates calories burned. Google it.

Key points:

1. Walking burns less per mile than running.

2. Running burns approximately the same per mile regardless of speed (10 cal difference per mile at 1:00 faster pace).

3. Calories burned over a 24 hour period following higher intensity exercises exceeds calories burned over a 24 hour period following lower intensity exercises (afterburn effect).

So....if your goal is weight loss then focus on higher intensity exercises (sprints, intervals, weight training) alternating with lower intensity lower impact exercises.

Alan