It is the quality of exercise, and not the quantity (duration) that yields perceptible change. Today, our lives are more hectic than ever. Making time for exercise can be difficult, if not impossible. There is good news. A mere 15 to 20 minutes a day is enough for fitness gains, as long as you are regular. This means that you do not have to spend hours sweating for great results.

The following tips help you get the most value for your time and supercharge your weight loss efforts. These tips save time, but also require consistency. You will see results within a few weeks if you stick with these ideas.

1) Do exercises that use multiple muscles, called compound exercises. Consult your gym instructor/ look online for a suitable program. For example, a squat uses the front and back of your legs as well as your butt. After each squat, add an overhead shoulder press using a light dumbbell and you will hit even more muscles. 'Isolated' exercises such as biceps curls and triceps extensions are less effective.

2) Focus on large muscle groups. Working your biggest muscles burns tons of calories and will give your metabolism a good boost. These muscles are your butt, thighs, back and core that is, lower back, abdominal and oblique muscles.

3) Increase the intensity of the cardiovascular workout. This increases the calorie burning effect and cuts the time. If you walk, then jog. If you run, then try the occasional sprint. An incline on a treadmill works well too. Instead of doing forty minutes of walking, jogging or low impact aerobics go on a bike or treadmill at a high intensity for twenty minutes. If you have been working out regularly for at least a month, you could try doing intervals.

4) Try periodic boosts in intensity. Exercise at a level that to you is hard, or very hard for two minutes. Then, lower your effort - but keep moving! - For one minute. Repeat this cycle for twenty minutes.

5) Double up your exercises. Rather than resting between sets, use that time to work a different muscle group. For example, alternate one set of biceps curls with one set of triceps dips. Alternatively, do a set of seated leg extensions with a set of leg curls. These are super-sets and they nearly double the number of exercises you can do in a short time.

6) Combine strength and aerobic workouts - Circuit training. Doing this type of work out gives you calorie-burning benefits with strength gains. For example, do a strength exercise for one minute. Without taking any rest, move on to another. Every two or three exercises add one minute of jump roping or your aerobic activity of choice for one or two minutes.

7) Squeeze in short bursts of exercise during the day - Before your morning shower and breakfast, or during your lunch hour, squeeze in two sets of ten of the following bare-essential moves: crunches, pull-ups, push-ups, squats and lunges. These calisthenics target and tone most areas of the body but do not take more than a few minutes to do. Short bursts of exercise add up. If you can accumulate 30 minutes of physical activity in a day in short bursts, you will get the same benefits you would if you did it all in one session.

8) Mix it up! Variation is the key to long-term progress. Monotony in an exercise routine leads to boredom, which will eventually lead to no exercise. A change in the type of aerobics, or your specific weight training routine will avoid this problem and will give you greater fitness benefits. You will burn more calories and stimulate muscles in a new way, achieving more in less time.