The American College of Sports Medicine is recognized as one of the top authorities on exercise and weight loss. In 2011, the ACSM released a revised set of exercise guidelines that include specific recommendations on time and intensity for cardiovascular, flexibility, resistance, and neuromotor exercises. In conjunction with the updated exercise guidelines, the ACSM gives clear directions on how much physical activity is needed for weight loss and maintenance.
According to the ACSM, you should perform a minimum of 150 minutes per week of moderate-intensity cardiorespiratory exercise. This recommendation can be met by completing 30 to 60 minutes of moderate-intensity exercise on approximately five days per week. As an alternative, you can perform 20 to 60 minutes of vigorous-intensity exercise on approximately three days per week. The ACSM stresses that the required daily amount can be broken up throughout the day.
Resistance training for each major muscle group should be done two to three days per week with a variety of exercises and equipment. Performing two to four sets of each exercise, with eight to 12 repetitions per set in order, will improve your muscular strength and power. The ACSM suggests a break of at least 48 hours between resistance training sessions to give the muscles time to recover.
Stretching exercises should be done at least two to three days per week. Static, dynamic, ballistic, and PNF stretches are all deemed effective. Hold each stretch for approximately 10 to 30 seconds to the point of mild tension or discomfort. Repeat each stretch two to four times until you accumulate 60 seconds per stretch. Before stretching, the ACSM suggests taking a hot bath or performing some light aerobic activity. Flexibility exercises are most effective when your muscles are warm.
Neuromotor exercises -- also known as functional exercise -- were part of the 2011 updates. They improve physical function and stability. The exercises should involve motor skills, proprioceptive training, and multifaceted activities such as tai chi and yoga, should be done two to three days per week for 20 to 30 minutes.
The ACSM suggests 150 to 250 minutes per week of moderate-intensity physical activity for weight loss. For most people, this breaks down to 30 minutes of exercise five days per week. People going for modest weight loss will need something more than 150 minutes a week. Those seeking clinically significant weight loss will need to exceed the 250 minute mark.