Maybe warm-ups need a good ad campaign. An ad for warming up would tell you that it burns calories, enhances your fat burning potential, prevents injuries, and more. By not warming up, you do miss out on many important advantages.

For your warm-up activities it is recommended to do 10 minutes of light aerobic type activity, consisting of several different moves, to prepare your body for circuit training. You will move at a leisurely pace, say 50% of your maximum heart rate. In that 10-minute span of time, you can expend up to 100 calories. When it comes to exerting energy, every little bit counts.

Throughout the full 10 minutes off your warm-up, your body will tap initially into sugar for energy. By the time you begin your workouts, you will get a less sugar to spare, so your body will dip into its fat stores for energy much earlier. The advantage, you guessed it, more fat is burned.

Think about what it’s like to start your car’s engine when it’s cold. It performs poorly, right? Well, muscles are the same way; they don’t work well until they reach the proper temperature. Warming up also increases blood flow to your tissues, so that more oxygen and more nutrients are channeled to your muscles for fuel. Increased blood flow also helps remove waste products from muscles, such as lactic acid, that makes you want to quit. Finally your warm-up speeds up neural responses. Nerve impulses travel faster, improving your motor skills, coordination, reaction time and agility. Warmed up muscles move faster and generate more force than cold muscles and they burn more energy which means your body is better primed to lose weight.

If your muscles are cold and stiff and you go full throttle into your exercise routine, you are inviting injury on a couple of fronts. Your muscles shouldn’t be used until they are warm and pliable. But in addition, when you warm-up properly, raising your muscle temperature your body begins to lubricate your joints for easier movement and your muscle tissue becomes more elastic. This is important for strength training exercises in which you will need to move weight or resistance through a full range of motion. All of these psychological responses to reduce the risk of over stretching or tearing muscle fibers and connective tissue.

Also, if you begin a workout without a warm-up, you may provoke an irregular heart rhythm. In studies of healthy people, abnormal heart rhythms were found in those who exercised intensely without warming up, but disappeared when an appropriate warm-up was included in their exercise routine.

Keep you back straight but not arched. If your back is curved while you add a weighted load to any exercise, you are placing  an unhealthy strain on your back

Activate your core (trunk muscles) when performing any movement. The more stable your core, the less risk of injury.

Isolate the muscle group you are working. Make sure you can feel those muscles – and only those muscles – during an  exercise. That means, for example, if you are doing a biceps curl, the only body part that should be moving is the portion  of your arm between your hand and elbow. Your back, shoulders and legs should not get in on act. That means no swaying,  rocking or any other ways of helping that weight up.

Choose a grip when using dumbbells that feels most comfortable and natural to you. Your grip should be firm but not too  tight. Squeezing the equipment wastes valuable energy that should be exerted in the exercise.

Always control the exercise – no rapid, jerky movements, which place harmful stress on the joint ligaments. Jerky motions  actually give the weight so much impetus that it practically glides to the midpoint of the repetition, using little muscular  force to get there. As a result, muscles encounter limited resistance. Without resistance, muscles aren’t properly  challenged and may not respond as well. If you can’t lift the weight without jerking it, then it is too heavy. Try a lighter  weight. Strict style and technique are more important than the amount of weight you lift.

At the midpoint or top of the exercise, pause for a second to tense your muscles. Then lower the weight slowly again,  accentuating the negative portion of the lift. Your muscles thus get maximum stimulation from the exercise.

Breathe naturally as you exercise. Never hold your breath. Holding your breath cuts oxygen supply to the blood and, coupled  with the exertion of the lift, could cause lightheadedness or fainting.