Keira Knightley's Abs

Though Keira claims she rarely exercises, her flat -- but not too muscular -- tummy she shows off in films like King Arthur is not just God-given. For natural-looking abs, you need to work all the different muscles in your abdomen and mix up your routine frequently. "Your body is very smart and will adapt very quickly," Gabe says, "so you want to change it up a minimum of every six weeks."

With proper form, bicycle crunches are a great way to trim your obliques: Place your hands behind your head and bring the inside of your shoulder to the inside of the opposite knee as the other leg extends out in front of you (this is more effective than bringing your elbow to your knee, which works the wrong muscles).

For your lower abs, do crazy eights: Lie on your back, squeezing your lumbar into the ground, and point your legs straight in the air. Circle them out, down and back up for eight reps, then repeat in the opposite direction.

Work your entire core with a more advanced move: Start with your shins on a stability ball, hands on the ground and body straight. Tuck in your abs as you roll your legs toward you and pull your torso up to an almost vertical position

Calorie Expenditure

Although you might think that physical exercise accounts for most of the calories you burn, it actually accounts for only about one third. In general, your calorie expenditure depends on three things:

(1) Your Basal Metabolic Rate. This accounts for about 60 percent of all calorie expenditure. Basal (or resting) metabolic rate is the amount of energy or calories your body consumes while at rest, in order to power the thousands of chemical reactions required to maintain health - such as, temperature, cell-repair, cardiovascular system and so on. Put simply, basal metabolic rate is an estimate of how many calories you would burn if you were to lie asleep for 24 hours, with measurement beginning 12 hours after your last meal to ensure that your digestive system was inactive and not burning calories digesting food.

(2) Your Physical Activity. Typically this accounts for about 30 percent of calorie expenditure.

(3) Dietary Thermogenesis. This is the calories you burn while digesting food. It accounts for about 10 percent of the total calories you burn.

What is the best exercise for weight loss?

Doing both aerobics and strength training is the optimal way to lose more fat and gain more muscle. If you are trying to lose weight, studies show that weight loss increases by 56 percent with aerobic and strength exercises combined.

Muscle may weigh more, but when you increase your muscle composition, the body is able to burn more fat, even when you are resting, because your metabolism is higher. A pound of muscle will use 350 to 500 calories per week to survive, while a pound of fat only needs about 14 calories per week. New studies have shown that building muscle helps your body fight disease better, too.

Strength training involving several sets of multiple repetitions using moderate weights will not result in huge muscles. Instead it builds bone mass and increases the metabolism, as well as toning and firming the muscles, giving a leaner look.

It is very important to do both aerobics and strength exercises. The aerobic exercises help your heart and lungs get stronger and help your body utilize oxygen more efficiently, which in turn helps with strength training and overall fitness. The strength exercise helps develop muscle, reduce body fat and maintain bone mass.

Aerobic Exercise is a type of exercise that elevates the heart rate and breathing for a continuous sustained period. This overloads the heart and lungs and causes them to work harder than at rest.

There are many options to choose from, bicycling, aerobic dance, swimming, walking, and stepping are all examples of aerobic exercise. Which ones to chose depends on your physical condition, your history, your interests and your goals. Many experts believe it is better to alternate between 2 or more types, to get a better workout.

There are two main types of aerobics- high impact and low impact. It is better to alternate between high impact aerobics (which are harder on the body and may cause more damage) and low impact aerobics, such as walking and swimming. This is called cross training, and helps reduce the chance or injury and overuse of certain muscles.

You will want to perform aerobic exercises at least 20 minutes a day for at least 3 to 4 days a week. If you are trying to lose body fat, or your physical condition is very good, then you may want to work longer at it. Try exercising up to 40 to 60 minutes 5 to 6 days a week.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~