Regular aerobic and strength training exercise offers numerous health benefits -- both short-term and long-term. In fact, after one exercise session, you may notice some physical and psychological changes. However, most of the benefits from a routine exercise program will start to appear within four weeks of consistent training.
The effect of exercise on your mood and energy level is one of the first and possibly most valuable benefits of your workout. Exercise, either aerobic or strength training, can improve your mood, reduce stress, fight depression, energize your body and improve sleep. In fact, just 10 minutes of brisk walking can help to improve your mood and energize your body. Performing three 30-minute moderate-intensity aerobic sessions a week for at least 10 weeks can reduce symptoms of depression, reports the Association for Applied Sports Psychology.
You may begin to notice that your aerobic endurance is improving in as little as two weeks when exercising just three days a week. The same exercise that was previously difficult or challenging is no longer quite as difficult to perform, or you can perform the same activity for longer. Whenever you exercise aerobically, your body responds to the stimulus by increasing heart rate and blood flow. Overtime, your body begins adapting to the stimulus by increasing capillarization in the muscle allowing for greater blood flow to the tissues, which can help improve aerobic endurance.
Gains in strength can occur in as little as one or two weeks after beginning a new strength-training program. These changes are primarily a result of neurological adaptations rather than muscle growth. Strength gains occur initially because the connections between the motor neurons in the spinal cord allow the motor units to act more in sync, which increases the muscle's ability to generate force. As a result, an untrained person may experience a 25 to 100 percent increase in strength gains within three to six months of consistent training, notes Jack H. Wilmore and David L. Costill, authors of "Physiology of Sport and Exercises."
Disease Risk Reduction
One of the significant benefits associated with regular exercise is reducing your risk for chronic diseases such as heart disease. The minimum recommendation for decreasing your disease risk factor is at least 30 minutes, five days a week of moderate-intensity aerobic exercise, such as cycling or brisk walking. However, the greatest benefit for reducing your disease risk is through a caloric expenditure of 4200 calories or more a week, reports the Cleveland Clinic. The caloric expenditure can be achieved through a combination of moderate or vigorous activity using a variety of different exercises, broken up into at least 15-minute-long training sessions.