Why Add Intervals to Your Workouts! from Tracey Mallett

Interval training is alternating short, fast bursts of intensive exercise with slow, less intense exercise often called steady state. It works both the aerobic and the anaerobic system. During the high intensity effort the anaerobic system uses the energy stored in the muscles (glycogen) for short bursts of activity. Anaerobic metabolism works without oxygen. The by-product is lactic acid, which is related to the burning sensation felt in the muscles during high intensity efforts. During the high intensity interval, lactic acid builds and the athlete enters oxygen debt.

During the recovery phase the heart and lungs work together to 'pay back' this oxygen debt and break down the lactic acid. It is in this phase that the aerobic system is in control, using oxygen to convert stored carbohydrates into energy. After repetitive training the body begins to build new capillaries and is more efficient at taking in oxygen and delivering valuable oxygen to the working muscles. This process is called adaptation response.

Over time the muscles will develop a higher tolerance to the build-up of lactate (the by product of high intensity training which causes the muscles to cramp and get sore), also the heart muscle is significantly strengthened. Overall, all these changes will result in a higher improved performance with the cardiovascular system, which enables you to work harder burning more calories and fat.

Interval training is a great way to spice up your workout routine adding some cross training to your workouts. What I love about interval training is that you can burn more calories in less the amount of time as steady state. Now as a busy working Mom this sounds very appealing, more for less time. This is the primary reason why most of my workouts have increased harder effort with lower intensities. The workouts are short but intense burning maximum calories through out the workout and at rest. According to the American College of Sports Medicine, more calories are burned in short, high intensity exercise.

Note: high intensity intervals need to be slowly introduced even for the experienced exerciser. Start off with short intervals
(1 to 4 minutes steady state) then progress to shorter steady state cycles. Remember everyday is different switch it up and you’ll never get bored. Your body will be constantly challenged in different ways this also decreases repetitive injuries and works a variety of different muscles.

Tips for Safety
1. Always make sure you’re warm before going in to an interval, I recommend my clients to walk or run for 5 minutes prior to starting the intervals.
2. Listen to your body, work within your own limits
3. Set reasonable goals - build up the intensity gradually
4. In the interval keep a challenging pace, you should feel form a scale 1-10 about a 7-8
5. Slow your pace down considerably in the rest period, give your body time to recover.
6. Train on a flat even surface and slowly introduce hills.

What are you waiting for? Go and get your running shoes on!