This question has come up a few times, and usually misconceptions abound.
Perhaps the most important one is that calories do not matter all that much. Consider this simple fact:
1 handful of peanuts = 500 kcal.
1 hour jogging = 300 kcal.
Most people are shocked when they realise how little calories one burns when exercising. (which should not discourage people from exercising – it should just show how misguided the “calorie” approach is).
In fact the average 2500 kcal a day the average Joe burns on a day are mostly used to keep one’s warm. Sit down in front of the TV all day long and you will burn 2000 calories (a bit more if you press the remote). If you want to burn calories, have cold showers in winter and wear no coats. In summer do the opposite. Your body will spend far more calories trying to balance your internal heat than you ever thought possible.
Calories are completely the wrong way to go about this. Let us say that you use 50 kcal in one hour of piano practice. Does that mean that six hours of piano practice equals one hour of jogging? Only in terms of calories. In terms of effects they are just not comparable.
First, jogging is an aerobic exercise: As you run your heart beat will go up, and without going into too much detail (which can be provided if there is interest), it is not unusual for joggers to run to a pace that keeps their heart rate at 135 – 145 bpm.
Now get a heart monitor (any sports shop will have one), strap yourself and play your most athletic virtuoso piece for as long you wish. If you have an average 60 bpm heart rate in rest, I doubt it will raise over 70 bpm (if it does, you better se a doctor). If you have the usual runner 40 – 45 bpm, you will barely get over 55 bpm. So how can you compare piano playing to jogging? You cannot.
Jogging mostly use your legs. In piano playing you do use the pedal, so I guess there is some leg usage. Can they be compared? Surely not.
This takes care of the aerobic aspect. What about the anaerobic exercises such as weight lifting? Again, most everyday activities require far more muscle strength (and that includes pressing the buttons of the remotes – they are surprisingly hard to press! And if like me you hop channels constantly, this can significantly increase your forearm and hand muscle strength). This means that when you play the piano you will be typically requiring far less strength from your muscles that you do when you go about your everyday business. So not a good anaerobic/strength exercise either.
We could go on to flexibility and the same would be true. Piano playing requires far less flexibility than everyday chores. So you will not develop it from playing piano and you will not require it to play the piano.
So what is it that piano playing develops (if anything)? It develops and requires to an inordinate degree – arguably more than any other activity in the universe – motor co-ordination and mental qualities (such as focus, concentration, memory, pitch recognition, etc.) As such it is an integrativeactivity par excellence, which other co-ordination and integrative activities (like jogging and skipping rope) do not come even closer.
This of course is the summary of the summary.
One last word: Although it is relatively easy and straightforward to determine the amount of calories in food (you just burn it), it is next to impossible to determine how many calories one spends in any specific physical (or mental) activity. So all the figures you find (and it is a very instructive exercise to google such – you will be amazed at the variation) are tentative, best guesses. But piano playing is right there together with pressing buttons on the remote.
If the subject interests you, I suggest you read:
Edward Jackowski - “Hold it! You are exercising wrong” (Simon&Schuster) which dispels many of the myths regarding exercise.
Best wishes,
Bernhard.