A well-developed six-pack is achieved by a combination of cardiovascular exercise, resistance training and of course, healthy eating. Understanding the structure of the abdominal area will help you see why two forms of exercise are required.

The top layer of the abdomen consists of fat. The only way to burn fat is by cardiovascular exercise, which will supply oxygen to the fat in order to burn it. Below the fat layer lie the abdominal muscles, which when developed make up a 'six-pack'. This requires resistance training (floor work using your own body weight as resistance). Until the fat is burnt off the top, the underlying six-pack will not be visible, no matter how toned it might be.

It is important to also train the muscles that support and oppose the six pack muscle in order to protect your spine, which could get injured by training just the main abdominal muscle. Also, your entire midsection will then look well-toned.

The six-pack routine

~ Cardiovascular exercise

Frequency -- 5-6 days a week
Duration -- Minimum of 30 minutes, non-stop (can go up to 60 minutes)
Intensity -- Brisk
Choice of exercises -- Walking, aerobics, swimming, cycling, stair climbing

~ Resistance training

Frequency -- 3-4 days a week
Sets -- Start with 2 of each exercise, consisting of 16 reps per set. You can increase to 3 sets as you progress.
Level -- Start off with the moderate level. Try the advanced once the moderate becomes easy to do.
Time of exercise -- Do this right after your cardiovascular workout since your body is warmed up.
Breathing technique -- Exhale as you lift, inhale as you lower.