which generally improve oxygen consumption and energy production. Physical activity targets several processes which are essential to maintaining good cardiovascular health. Furthermore, many studies demonstrate the positive impact of exercise in treating depression; others have proven that regular physical activity – at least three times a week – boosts the brain’s metabolism and diminishes the risk of Alzheimer’s by 40% in seniors .It also increases bone mass, thereby helping to prevent osteoporosis. And that’s not all; physical activity reduces stress, improves sleep and keeps immune function in good working order, heightens libido and self-confidence, by releasing endorphins into the brain, which ‘reward’ physical activity by triggering a feeling of euphoria. On top of increasing tissue sensitivity to insulin and improving carbohydrate metabolism, regular physical exercise helps avoid, or reduce, the effects of aging on reaction time– the time required to react to any given situation. 65-year-old subjects who exercise regularly have identical, or sometimes even better reaction times than 20 year-olds who don’t exercise. They also improve their ‘fluid intelligence’, that is, their problem-solving skills.