Everybody knows that exercise is essential to keep us healthy. It lowers the risk  heart disease, and helps us to maintain a healthy weight. It also reduces stress and makes us happier. Doctors say that exercising  cold weather is even better for us. Going  a jog or even a swim when it's chilly or freezing outside has extra benefits  our physical and mental health. The reason  this is that the cold gives our heart a more energetic workout. Dr Angela Pepdjonovic,  the Hospital  Special Surgery  New York, explained why. She said: "Your heart has to work a little bit harder to pump blood  your body in the cold. This can help to boost your endurance  time."
Dr Pepdjonovic said cold-weather workouts can help the body burn calories  a faster rate. She said: "As your body is required to work harder to maintain its core temperature, you actually increase your calorie burn  exercising in the cold." Physical activity  cold temperatures can boost our metabolism, which helps us lose weight.  the cold, our metabolism slows , so we can preserve fat and keep warm. Another benefit is that being  natural light helps to reduce our stress. This is especially so  people who suffer  Seasonal Affective Disorder (S.A.D.). This is a type of depression caused  the shorter, darker days of winter. It is more common in people who live far  the equator.