Earlier this week, I gave a mini 101 on what muscles make up our abs and when to give them a rest. Today, I'm offering you my six favourite ab-toning exercises.

When designing your abdominal workout keep in mind the golden rule of resistance training: The last few repetitions should be difficult to complete. If your abdominal exercises are performed correctly, 16 to 24 repetitions for one to three sets of each exercise, should be sufficient.

If you can perform more than 24 repetitions of an abdominal exercise with ease, then you are either a) not providing enough resistance, b) performing the repetitions too quickly, or c) using improper form, which means you're not properly engaging your abdominals.

1. Planks
The set up:
• Lie face down flat on a mat; place your hands underneath your shoulders.
The move:
• Forward plank: lift your body off the ground with your knees or toes on the ground and hold for 30-60 seconds to work deep into the core muscles.
• Side plank: from your forward plank shift your weight into your right hand and rotate your entire body so that the left side is facing the ceiling, then do the other side.

2. The Bicycle
The set up:
• Lie face up, flat on a mat with your lower back pressed to the ground.
• Place your hands behind your ears.
• Feet off the floor, knees above your hips.
The move:
• Touch your left elbow to your right knee, then your right elbow to your left knee.
• Work at a steady pace; inhale as your elbow touches the knee; exhale to extend.

3. The Captain's Chair
The captain's chair is a piece of equipment found in most gyms. It looks like a tall chair with arms but no seat.
The set up:
• Stabilize your upper body by gripping the hand holds and pressing your lower back against the back pad.
• Your body is in an upright position with your legs hanging below your torso.
The move:
• Lift your knees in toward your chest in a controlled manner.
• Return your legs to the starting position.

4. Vertical Leg Crunch:
The set up:
• Lie face up, flat on a mat with your lower back pressed to the ground. Place your hands behind your ears, elbows out.
• Extend your legs straight up over your hips with a slight bend in the knees, cross your ankles.
The move:
• Contract your abdominal muscles; lift your torso toward your knees.
• Keep your eyes towards the ceiling, maintaining a small space between your throat and your chin.
• Exhale as you lift, inhale as you return to the starting position.

5. Crunch on Exercise Ball:
The exercise ball is a large ball which is excellent for strengthening core muscles. Not only does using the ball create a unique range of motion, it also causes many of your abdominal muscles to fire as you aim to keep balance (no one wants to drop off the ball).
The set up:
• Sit on the ball with your feet flat on the floor.
• Let the ball roll back slowly so you can lie down on it. Your thighs and
torso are parallel with the floor.
• Cross your arms over your chest, support your head by slightly tucking your chin in toward your chest.
The move:
• Contract your abs, raise your torso to approximately 45 degrees and then lower back to the start position.
• Exhale as you lift; inhale as you lower.
Helpful hints:
• For more stability, place your feet wide apart.
• To make it more of a challenge, place your feet closer together.

6. Reverse Crunch:
The set up:
• Lie face up flat on a mat with your lower back pressed to the ground. Place your hands behind your ears.
• Lift your knees over your hips at a 90 degree angle, and cross your ankles.
The move:
• Press your lower back into the ground and contract your abdominal muscles and reach your legs towards the ceiling, keeping them bent.
• Exhale as you lift, inhale as you return to the starting position.

Keep the following in mind when it comes to abdominal work:
• Your muscles need a 48 hour rest period to repair and become stronger.
• Your six pack (rectus Abdominus) is only one of six abdominal muscles.
• Diet and lifestyle habits are as much at play when it comes to the appearance of your abdominal area.
• Body type is also a factor when it comes to the appearance of your abdominals.

Sarah Brown is a very healthy woman. She is not only a fitness instructor at Goodlife where she teaches Body Pump, Body Flow and yoga but she is also a registered holistic nutritionist. If you have a question for Sarah, leave a comment below and she will try and help, but note that not all questions will be answered.