To really benefit, break out of a walk into a jog

RUN CLINIC:In her fortnightly column, RUTH FIELDcompares the benefits of running, even running very slowly, with power walking

JUST NEED to ask you something. I run very slowly. Pretty sure there’s people who walk faster than me. How beneficial is very slow running/jogging compared to power walking? I’m not planning on giving up my running to power walk because I run now for other reasons (not just to keep fit), but I just wondered. Thanks.

Firstly, I must confess, so do I sometimes (run slower than I walk), and I’m sure there are a hell of a lot of others in the same boat so you are not alone in wondering if you might be faster in reaching the end of your circuit if you just swapped your jog for a fast walk. This is to be expected at the beginning of your running adventures. The more you practise jogging, the better you will become at it and the faster you will be able to get round. In no time at all you will be able to jog 4.5-5mph which is when the magic really begins . . .

There are undoubtedly benefits to power walking: it is good cardiovascular exercise, with the added bonus of not impacting your joints so much, making it the ideal way to start out when you are desperately trying to extricate yourself from a committed relationship to the couch and the remote control and have never before run farther than the bus stop.

In fact, it is an essential precursor to learning to run, and indeed is a very good alternative to jogging for those who are extremely overweight and/or have genuine problems with their joints or other medical concerns which make jogging an impossibility.

But if you can jog, there is no doubt that it is the superior way to use your legs. It is better for your heart, for the number of calories you burn, for muscle tone in your legs and bum, for building fitness and for getting drunk on endorphins.

For an average person, walking at 3.5mph (a typical power walking pace) burns around 346 calories per hour while jogging at 5mph burns 728 calories per hour. Once you are able to jog at a rate of 5mph, your jog is going to burn up double the number of calories over an hour than a fast walk would, so you are miles better off concentrating on improving your jogging speed as opposed to switching to power walking.

And there is another compelling reason to jog rather than walk which seems counterintuitive at first blush: the motion of jogging helps calf muscles to work more efficiently than when we are walking briskly.

Studies have shown that the calf muscle acts as a car clutch, effectively allowing you to shift into a different gear.

A team of scientists at North Carolina State University noted that walking fast makes the muscle work harder but provides less energy, with this inefficiency ultimately decreasing our stamina. However, jogging at a speed of just two metres per second prompted the muscle to change its length more slowly, providing more power even though it isn’t working as hard.

Study author Dr Gregory Sawicki propounds that – Olympic race walkers aside – people generally find it more comfortable to run than walk when they start moving at around two metres per second (about 4.5 miles per hour).

Ultra sound imaging of muscles on a treadmill shows a gentle run is actually less tiring and is better for your muscles than a brisk walk.

So good news: once you are able to jog a bit quicker, not only will you get more bang for your buck, but your muscles will actually find it easier than walking fast and you will simultaneously improve your fitness.

A gentle jog is more efficient, easier on your muscles, releases more energy and builds more stamina than a power walk. So, it is without question a much better use of your time.

The Grit Doctor says:

Use your clutch to crank it up a gear.

RUTH FIELDis the author of Run Fat Bitch Run. Tweet your running queries to Ruth at: @gritdoctor.

See also: irishtimes.com/bodyandsole