The recommended duration of cardiovascular exercise for good health and disease prevention is at least 30 minutes per day. The American College of Sports Medicine suggests that 60 to 90 minutes of moderate exercise might be necessary for weight loss or to maintain weight loss. If you are training for a specific endurance event, two or more hours is acceptable, but you should gradually increase duration, focus on cross-training and know the symptoms of over-training.
Endurance events, including half-marathons, marathons, triathlons or distance cycling races can involve two or more hours of cardiovascular exercise. Performing that amount every day is not recommended. One or two long cardiovascular sessions per week will be sufficient if you are training for a specific event. Before increasing your cardiovascular time, define your goal and devise an appropriate training plan that includes long- and short-duration exercise with adequate rest to achieve your goal.
Cross-training increases aerobic fitness, muscular endurance and decreases the risk of injury. According to an article published in the January/February 2011 issue of American Fitness, too much of the same exercise often results in an overuse injury. If you perform the same cardiovascular workout each day, try doing other modes of exercise to prevent injury. Cycling, running, stair climbing, swimming, rowing and elliptical training are effective calorie-burning exercises for cardiovascular fitness.
A web page on the Princeton University website reports fatigue is the most common symptom of over-training. Moodiness, depression, irritability, altered sleep patterns and persistent muscle soreness can result from exercising too much. Single-sport athletes tend to suffer from over-training more often than those who participate in more than one activity. If you have lost enthusiasm for exercise because of fatigue or have symptoms of over-training, add rest days and other types of exercise to your routine.
One hour of vigorous-intensity exercise per day is beneficial for aerobic fitness and has been shown to significantly suppress appetite, according to PhysOrg.com. If weight loss is your goal, you can divide workouts into morning and evening sessions for a longer calorie-burning effect. Training for long-distance endurance events takes time. Listen to your body and incorporate rest or lighter workout days as needed to allow for sufficient muscle recovery.