Here is some "food for thought" on Hockey as a form of exercise:
Caloric Consumption:
A regulation hockey game is one hour long. According to fitness resource website HealthStatus, a 160-lb. person playing one hour of hockey burns 586 calories. A 200-lb. person playing for the same amount of time would burn 732 calories.
Exercising in the Cold:
"But even when the temperatures start to plunge, there are plenty of reasons why exercising outside in the cold is better for you than working out in the warm.
In the cold, you burn more calories because the body uses more energy to generate heat. And because you sweat so much less than you would on a hot, humid day, you are much less likely to become dehydrated.
Plus, you can work out much harder in chilly temperatures than in hot ones — heat taxes the body so much more and the dangers of working out in excessive heat outweigh the benefits."
reprinted- http://www.dnainfo.com/new-york/20120113/manhattan/top-reasons-why-cold-weather-exercise-beats-hot-weather-workouts
Competition:
Hockey is a team sport. Practicing and playing with other people can increase your motivation to keep exercising, increasing your successes with weight loss. To lose one pound of fat, you must burn 3,500 calories. You can burn anywhere from 50 to 500 or more calories per hour depending upon the activity you are performing, but it usually takes a combination of reduced calorie intake and increased physical activity to create a significant enough caloric deficit to lose weight. Competitive sports can play an important role in your fitness routine.
