From this article Short workouts: Will exercising for 15 minutes once a week get you fit?
“The key to the short workout’s success revolves around a concept known as high-intensity interval training (HIIT). HIIT is a heightened form of interval training that involves alternating between periods of short, intense physical activity and fixed periods of low activity or rest. Intervals can include anything from fast squats and pushups to weight lifting and powerful cardio.”
The goal in exercise is expose the body to more than it is used to handling. If given enough time for recovery the body as a form of self-protection will come back stronger, more enduring, and more able to withstand the stresses previously placed on it. That can take one hour or two, or it can take less than ½ an hour. Regardless of the time period at the end the session you want to come out spent.
A prescription for the shorter sessions: Warm up on the bike (optional). Cut out the warm up sets. Cut out the intermediate sets. Start each rep slowly and safely until warmed up for that particular movement. Lift heavy demanding weights through a very safe range of motion. Minimize time between machines. Relentless go from one exercise to the next working all the major muscle groups at least once. Do not pace yourself. If after 20 minutes you have gas left in your tank and want to do more then you definitely didn’t do it right.
If you did it right your metabolism will be significantly raised for the rest of the day and on into the next. HIIT burns more calories than any other form of exercise particularly after the workout is over (See: EPOC – Excessive Post-exercise Oxygen Consumption). It will take your muscle days to recover and repair. The repair and rebuilding is metabolically expensive - it demand calories. It is cardiovascular demanding and positively affects cardiovascular health. Your blood pressure will easier to control.
Do it once or twice a week. Compliment it with sprint training on suitable aerobic equipment a couple of more times a week coupled with modest dietary changes. All this will take you a little over an hour of your week. If you haven’t exercised in years build up to this slowly. If you stick to it for six months (@ 25-35 total hrs.) your health will be significantly improved.
A little strength training, an active lifestyle, and better eating choices can have profound effects on one's fitness and health. These changes do not require endless hours in the weight room. Our fitness trainers at New Orleans Personal Trainers and at Austin TX Personal Training can guide you through an effective strength training program that will achieve life-changing results.