All things equal, what is healthier, 15 min of daily biking or jogging?

Both are great. But 15 minutes is NOTHING and won't do you any good. You need to power-walk, jog or bike for at least 45 minutes to 1 hour. If you are trying to lose weight, then you need to do one of those things every day. If you are just trying to tone yourself, then you can do that every other day.

It takes about 15 minutes just to get your heart-rate up, then you need to sustain that heart-rate for at least 25 minutes....then a 10-15 minute cool-down to get your heart rate to slow easily. That's why just 15 minutes is nothing.

Biking, it works muscles you dont normally use although jogging burns more fat than biking over the same distance, but using those underused muscles will make up for the fatburning difference. Plus its a lot easier on your feet

Both are good cardiovascular exercises. It depends on which you prefer or you could bike some days and jog on others. If you have any problems with your knees, biking might be easier on your joints..

From an exercise standpoint, jogging is better. It requires you expend more energy to keep moving and thus you burn more calories.

Bicycling you can peddle a few times and coast a good distance. What good does that do you?

Do either of those for an hour, rather than 15 mins.

I think biking would be better. Riding on bumpy terrain has been shown to help build bone mass. Also, it is less hard on the joints and feet.

biking, jogging will eventually destroy your knee joints.