What is better for me, cycling 5 miles or walking 5 miles?

Paul Ryder, Ashton under Lyne, UK

• There are so many variables in this calcualtion as to make any answer pretty meaningless. How many gears does your bike have? What gear will you be cycling in? Are you going uphill, downhill or both? You might be able to freewheel the whole way, so running would certainly expend more energy. What kind of surface are you cycling/running on? How fast are you planning to run/cycle? The list of variables is endless.

  Max Wurr, Stanmore UK

• It depends on the relative intensity of each effort, and whether you want to be a better walker or a better cyclist. It also depends on what you mean by 'better for you'.

  If you wish to gain an aerobic training effect - that is, to improve oxygen uptake and utilisation in the muscles involved in the activity in order to improve your performance at that activity - then you would need to work at around 70 to 90% of your maximal aerobic capacity in either activity.

  This would mean cycling fast for 5 miles, or walking at much higher than normal fast walking pace for 5 miles. In practice, it would be very difficult to walk this fast without practice. On the other hand, cycling would allow you to reach the training threshold with less technical difficulties. Hence it may be easier to improve your aerobic power at cycling than your aerobic power at walking.

  It is important to note that aerobic power improvement is specific to the muscles used in the training activity - principally the quadriceps in cycling and the plantar flexors in walking. Thus cycling training will not make you a better walker, and walking training will not make you a better cyclist. In fact, neither exercise will confer any fitness advantages upon any activity except the one which is performed in training.

  If you merely wanted to reduce your risks of heart disease, then you would not need to reach any training thresholds to gain benefits. Both activities undertaken at an easy intensity may be equally able to reduce 'bad' cholesterol, increase 'good' cholesterol and reduce blood pressure. However, walking 5 miles may use more energy than cycling 5 miles on the flat, so the weight control component of walking may be more beneficial.

  In addition, walking carries less risks of being killed or injured in a road traffic accident. Overall, then, walking may be better for you if you wish to maximise your health without getting 'fitter'.

  Mark Perry, London, UK

• Cycling, especially if your in trouble with the wife.

  Tom Yates, Manchester UK

• Given that it would probably take anywhere between 30 minutes and a hour to walk five miles (based on pre-existing fitness level) compared to 15-30 minutes to cycle it, walking is better for you insofar that it keeps your heart rate elevated in a target workout zone for a more sustained period of time. Conversely, cycling will elevate the heart rate to a higher level (potentially too high for the unfit) but you would complete the distance before you have really started giving yourself any benefit.

  Chris, Hong Kong

• Depends how much of a hurry you are in and what the weather is like. You'll probably use more calories walking (which will be good if you're overweight) unless you cycle uphill and do it fast. You'll get wetter cycling if the weather is wet so I'd consider walking instead.

  Shaun, York UK

• Of course it depends what you mean by better. Cycling is more efficient than walking, so you'll probably work harder by walking briskly and probably exercise your heart, lungs and major muscles more. On the other hand, cycling is probably less hard on your hips, knees and ankles than walking. I find it more fun to cycle five miles on roads in town than to walk those miles - though the cycling is probably more dangerous - so I'm more likely to cycle regularly than to walk. Overall, regular exercise is probably better for your health than idleness, so the best exercise is probably the one that you will gladly repeat regularly and often.

  Beefy, Bisham Abbey UK

• A bicycle gives mechanical advantage compared to an unaided human. This would apply almost regardless of any other variables, unless the bike is ridiculously heavy or in the wrong gear. Otherwise, why bother using a bike? So, if it's easier to use the bike, walking is better for you because it is more work. It's also safer...

  Simon Blake, Shrewsbury