Cycling vs. Running ‘which burns more fat?’ and ‘which is harder?’

I’ve followed a thread on the Facebook and there some views aired on ‘which burns more fat’ and ‘which is harder’.

So which is it? Lets find out:

Muscular stress

Running is a high impact active, it involves repeatedly striking the ground with impact force of roughly 2 -3 times body weight. That means that as a 70 kg human being, your leg muscles, bones and ligaments are subject ~210 N of force every single step of the way. Now cycling, on the other hand has negligible impact. The bike is supporting your body weight and eccentric forces acting on the musculature and bones are negligible. It’s worth noting this is true of road cycling, but not mountain biking.

Muscle contraction type also differs. In cycling muscle contractions are concentric, that is the muscle is lengthening. This is also the type of contraction that produces the least force. In running there’s the whole array of muscle contraction type: concentric (in propulsive phases) and eccentric on the breaking phases. The degree of muscle activation in the running movement actually occurs just before ground contact in running as the body ‘pre-empts’ the impact.

So which is harder on the muscles? Running by far. This is the reason we see bike races lasting weeks, while just one marathon takes weeks to recover from. You can do a massive amount of cycling before needing to stop.

Why is it ‘easier’ to run hard than cycle hard? In cycling the volume of muscle used by the activity and requesting oxygen from the respiratory system is less (60% versus 80% in running).

Ventilatory and cardiovascular stress (heart + lungs)

In both sports, trained athletes are able to attain ‘VO2max’ -that is maximal aerobic capacity, or the maximum amount of oxygen that your body can absorb. The body, like a combustion engine needs oxygen to produce energy: fuel + oxygen ≅ energy; heat + work. VO2max represents a ceiling of how much energy can be ‘burned’ aerobically. Where VO2max can’t be attained it’s unlikely that that exercise will be as effective at burning fat as these ‘big muscle group’ exercises. Other factors leading to performance in sport are efficiency and energy derived through other (anaerobic) mechanisms, also at which point one reaches Lactate threshold (LT), which varies from sport to sport and basically defines rates of sustainable exercise.

For sub-maximal exercise, a roughly linear relationship  exists between heart rate and energy expenditure -regardless of exercise modality; the unit cost of oxygen per amount of energy remains very similar regardless of ‘metabolic substrate’ (that’s fuel; Carbs, Fat, Protein). So what we’re seeing is if you cycle at the same intensity you run, you’ll burn round about the same amount of energy!

Excess post-exercise oxygen consumption (EPOC) is also about the same when comparing cycling and running, so post exercise fat burning remains about the same for both.

So which is harder on ventilatory/cardiovascular system? They’re the same more or less, it depends how hard you exercise and not how you exercise.

So which burns more fat? We’re back to the question of exercise intensity, rather than modality…

N.b. one important aside: LT will likely come a different stages in the same person doing the two sports. Generally LT is higher while running than cycling, except trained cyclists: If you’re a runner, runner is ‘easier’. If you’re a cyclist, cycling is easier. If your neither, then running is easer. Non-cyclists find it hard to reach VO2max on a bicycle.

Mental stress

The much ignored nervous system: the one that actually gets you up, out and exercising is obviously also an important factor.

Both sports provoke a large amount of cognitive load to people new to them: There are literally billions of ‘factors’, degrees of freedom open that the mind has to deal with. Think about what’s going on: posture, muscle activation, sensory feedback from the body, sensory feedback from the environment, cognitive interference, spatial processing and navigation, etcetera… An awful lot more is happening that just sitting on the couch! This can cause an overload of the neural structures that have to process the information. Hence it is interpreted as ‘unpleasant’ by those unaccustomed to momentum sports. People beginning sport often make subconscious efforts to reduce cognitive load by exercising indoor, listening to music, exercising at a reduced intensity, picking exercise modalities which minimize the amount of, or disassociating themselves from the activity at hand by using distraction techniques, such as counting strides, singing, thinking about something else.

With practice a person develops automatic ‘coping mechanisms’ (schema) where things that would normally take up their attentional resources become automatic.

So which is ‘less stressful’ I am not aware of a comparison between exercise modality and rate of arousal (although it probably has been done), so have to go on common sense here. I would guess running causes a greater amount intrinsic stimuli while cycling causes a greater amount of stimuli from the environment. In colloquial: Running hurts more than biking, but the movement is slower, so you have less things like cars, obstacles, dogs and potholes to deal with, biking is more stressful due to environmental factors. Given rates of participation in sport I’d guess about the same as cycling and running have a very similar amount of participants.

Coming next we’ll get Ricardo to throw swimming into the equation.


Nilsson, J. and Thorstensson, A. (1989) ‘Ground reaction forces at different speeds of human walking and running.’ Scandinavian Physiological Society,  136(2) pp. 217-227.

Scott, C. B., Littlefield, N. D., Chason, J. D., Bunker, M. P., Asselin, E. M. (2006) ‘Differences in oxygen uptake but equivalent energy expenditure between a brief bout of cycling and running’ Nutrition and Metabolism, 3(1).

Keytel, L. R., Goedecke, J. H., Noakes, T. D., Hiiloskorpi. H., Laukkane, R., van der Merwe, L., Lambert, E. V. (2005) ‘Prediction of energy expenditure from heart rate monitoring during submaximal exercise.’ Sports Science, 23(3) pp. 289-97.

Ekkekakis, P. and Petruzello S. J. (1999) ‘Acute Aerobic Excercise and Affect.’ Sports Medicine, 28(5) pp. 337-347.

Wilson, M. (2008) ‘From processing efficiency to attentional control: a mechanistic account of the
anxiety performance relationship.’ International Review of Sport and Exercise Psychology, 1(2) pp. 184-201.

Derakshan, N. and Eysenck, M. W. (2009) ‘Anxiety, Processing Efficiency and Cognitive Performance. New Developments from Attentional Control Theory.’ European Psychologist, 14(2) pp. 168-176.

Sport England (2013) Active People Survey 7. [Online][Accessed on 14th November 2014]

Barefoot running?

why I started running barefoot -independently of the fad

n.b. I am not advocating one way of running over another -this is my story.
I started barefoot running purely because it makes logic mechanically speaking: Placing weight at the end of a lever, has a bigger moment than the lever alone. Therefore, logically barefoot running should be more effective in long distance events. Some sources claim a saving of 1% energy per 100g of each shoe, others 50g. What’s certain is that shoe weight is a factor (albeit marginal) in running performance.

first steps

It’s a little know, but well studied factor, is that cycling can produce fragile bones. The intensity of exercise and the lack of impact mean calcium is drawn from the bones at a greater rate than it’s deposited, resulting in weak bones. N.b. if you are a cyclist training a lot it’s good to maintain a component of weight bearing exercise in your program.

Sixty-three percent of NWB [non-weight bearing] athletes had osteopenia of the spine or hip, compared with 19% of WB [weight bearing] athletes. Cyclists were 7 times more likely to have osteopenia of the spine than runners, controlling for age, body weight, and bone-loading history. Rector, R. S. (2008)

I was aware of the importance of running while cycling and would always do quite a lot of running each off-season, occasionally even reaching fairly respectable levels of running form.

Bike shoes, especially the excellent Bont cycling shoes I used provide so much support for the foot, it’s essentially limp in the shoe. While this is great for cycling performance, it also means the foot structure hasn’t got much stimulus to develop. So I began running barefoot also, to strengthen my feet. I know the rationale is hardly scientific.

The first time I ran barefoot, I could barely get out the door and after 50m running on the road would be reduced to a walk. I was aware something wasn’t quite right and did what comes natural, which is, I started running on the mid to forefoot. Now I can run proficiently barefoot.

some more ‘untested’ rationale

I’ve done a fair bit of studying of ‘ground reaction force’ data collect from a force plate in a Laboratory both in Loughborough and a couple of years ago at MMU. While I’ve got knowledge in the area I haven’t read very deeply and I haven’t run any tests on barefoot running personally.

When people run with shoes, they slam their ankle into the ground, creating a ‘force spike’ which, given this force doesn’t contribute to forward momentum directly, is absorbed by the shoes and lower leg muscles, dissipated as noise and heat means it’s essentially wasted.

shod heel strike
normal force profile for a heel strike wearing shoes.

Generally experienced barefoot running present ground reaction force data without this ‘spike’. Also this running style (forefoot strike) loads the muscles differently, with the gastrocnemius (calf muscle) in particular acting like an ‘elastic band’ storing elastic potential energy to then convert that to forward momentum.

barefoot strike
this is what the vertical force profile for a barefoot strike looks like.

minimalism shoes and proprioceptive feedback

The great thing about being barefoot is that it opens up a whole other ‘tactile’ dimension to running that helps control the movement I find: You know what your foot is doing on the ground. With minimalist shoes, I found this didn’t happen and that in some ways I had the worse aspect of both shoes and barefoot running. I.e. it reduced feel and reduced protection.

Due mostly to gung ho last minute training but also to crappy shoes I gave myself an injury. This wasn’t the fault of the shoes, but as a result of my idiocy: Running needs to be adapted for the environmental conditions, equipment and state of physical conditioning.

One thing that puts people off running is the fact it takes so long to adapt. You tell a sedentary person that they’ll be walking and cross-training for months before they should blast out a few km and they drop all notion of training there and then. However it’s the responsible thing to do. There are serious risks to engaging in heavy exercise without a sensible routine to get started.

When I did the half Ironman distance race in March I also found my musculature wasn’t strong enough to support good(?) technique at the end of such a long race. So training and how this training is done is by far the most important factor in injury prevention

Performance gains?

I’ve had no performance gains what so ever since running barefoot, in fact, maybe a slight decrease in performance. However, it’s early days and I have yet to put in a really good run either in triathlon or running alone. In training and in the (hilly) Luz triathlon I’m running 3:44 per km, equivalent more or less to 6′ miling or 16kph, so a bit shabby. In a test I did at the running 3:30 per km about four weeks ago and recently ran at 3:35 in an aquathlon. It seems I am slower than before by about 0.5 kph.

why I stuck with minimalist shoes

I got a fairly fancy pair of Saucony Hautori minimalist shoes. These shoes improved my performance because they gripped the ground better than running barefoot allowing a longer stride (again this is ‘untested’). One problem running barefoot I found was bare feet don’t ‘grip’ much and some stride length is lost. I still do a couple of km after each run barefoot.

the argument against barefoot running

If your in tune with the topic you’ll no doubt be aware of the ‘Vibram’ Lawsuit. There a good write up on The Science of Sport website:

The big thing against barefoot running is ‘puncture wounds’, i.e. stepping on something sharp. I’ve had blisters running barefoot and with minimalism shoes did give myself a stress fracture. On rough road surfaces at a high pace I find the skin can last about 6km, but I haven’t pushed it further to developed stronger skin. I use it in complement to normal running training with shoes.

If you run on glass or something, you’ll probably get some sort of injury. The trick is to see and feel where you place feet. I’m sorry, but this is common sense. If you get up and like, do something stupid like a half Ironman untrained, you will probably get injured no matter what equipment you’re using… It’s about being patient and taking care with you training.

Lower leg injuries are another common complaint: Achiles tendon and calf muscle especially. I understand why, was when you start running barefoot, this segment takes a battering and quickly fatigues, in fact I would find it hard to train on repeated days as the muscle was still recovering. Further into the process of habituation it’s a non factor. I don’t ‘extra’ tiredness in the muscle, it feels fine.

Perhaps the most annoying aspect of barefoot running is people gawking. I could be running down the road buck naked and people wouldn’t be so surprised. Maybe we should be analysing the problem from a Psychological perspective rather than a Biomechanical one :-D.

the fact of the mater

Running style has to be adapted for the conditions and the footwear. What’s true is that injuries are common and this has probably got more to do with poor physical conditioning of the individual and the hard surfaces people tend to run on.

I’ll be returning to this topic in the future as I learn more and gain more experience.


Rector, R. S., Rogers, R., Ruebel, M. and Hinton, P. S. (2008) ‘Participation in road cycling vs running is associated with lower bone mineral density in men.’ Metabolism,57(2) pp. 226-232

Daniel Lieberman et al. (no date) ‘Biomechanical Differences Between Different Foot Strikes’ Biomechanics of Foot Strikes & Applications to Running Barefoot or in Minimal Footwear.
[Online] [Accessed on 18th May 2014]

Tucker, R. (2012) ‘The Vibram lawsuit, barefoot running and science perspectives.’ 15th of May. The Science of Sport. [Online] [Accessed on 15th May 2014]