Staying active and exercising enough can be a difficult thing to do when combined with a 40-hour work week and an active family/social life. The American College of Sports Medicine gives guidelines for how much exercise and what intensity is enough to stay physically healthy. Its recommendations are as follows:
Exercise three to five days each week
Warm up for five to ten minutes prior to exercise
Maintain your exercise intensity for 30 to 45 minutes
Gradually decrease the intensity of your workout, then stretch to cool down during the last five to ten minutes
If weight loss is your major goal, then participate in your aerobic activity at least 30 minutes for five days each week.