It is speed skating.The skater has to go as fast as they can .It is unknown which burns the most calories.
Hockey, 5000m speed skating and long crosscountry skiing
running, but swimming still burns a lot
It is most definatly a sport. You sweat and it burns alot of calories/fat. So yes, it is a sport.
cross country skiing
swimming and sprinting
tennis burns off the most calories
the exercise that burns the most calories per hour is jumping jax and jogging in the same spot