Interval training: a good way to cross train
Interval training is simply alternating bursts of
intense activity with
intervals of lighter activity.
Interval training works both the
aerobic and the anaerobic system. During the
high intensity effort the anaerobic system uses the energy stored in the
(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.
This repetitive form of training leads to the adaptation response. The body
begins to build new capillaries, and is better able to take in and deliver
oxygen to the working muscles. Muscles develop a higher tolerance to the
build-up of lactate, and the
heart muscle is strengthened. These changes result
in improved performance particularly within the cardiovascular system.
Interval training also helps prevent the
injuries often associated with
repetitive endurance exercise, and they allow you to increase your training
intensity without overtraining or burn-out. In this way, adding intervals to
your workout routine is a good way to cross train.
Circuit training is a common method of interval training.
The benefits of Interval Training:
You'll burn more calories. The more vigorously you exercise, the
more calories you'll burn
— even if you increase intensity for just a few
minutes at a time.
You'll improve your aerobic capacity. As your cardiovascular
fitness improves, you'll be able to
exercise longer or with more intensity.
Imagine finishing your 60-minute walk in 45 minutes — or the additional
calories you'll burn by keeping up the pace for the full 60 minutes.
You'll keep boredom at bay. Turning up your intensity in short
intervals can add variety to your
You don't need special equipment. You can simply modify your
Rules for Interval Training
Undertake a period of
Continuous running before starting Interval
Consider the various elements of the session and ensure that they are
within the scope of the person in question.
The length of the work interval, longer gives a better effect.
The pace should be comfortable raising the individual's
heart rate to
the required % of
The number of repetitions should reflect the condition and age of the
rest interval should enable the person to
jog and bring the heart
rate down to near 100-110 bpm
Improvements can be made by altering any of the variables, however the
coach should only change one variable at a time.
All changes should be gradual in nature and take place over a period of
Ensure the surface to be run on is flat and even. It is usual to do
interval training on a track although it can be done on good quality grass
playing fields. Roads are not a suitable surface because of the pounding
Precautions for Safe Interval Training
warm up before starting intervals
Assess current condition and set training goals that are within your
Start slowly. (for example:
walk 2 minutes/ run 2 minutes) In general,
longer intervals provide better results
Keep a steady, but challenging pace throughout the interval
Build the number of repetitions over time
Bring your heart rate down to 100-110 bpm during the rest interval
To improve, increase
duration, but not both at the same
Make any changes slowly over a period of time
Train on a smooth, flat surface to ensure even effort
You can also use circuit training as a form of interval training
Variables used in an interval training program:
Intensity (speed) of work interval
Duration (distance or time) of work interval
Duration of rest or recovery interval
Number of repetitions of each interval
Interval training isn't appropriate for everyone. If you have a chronic
health condition or haven't been exercising regularly, consult your doctor before
trying any type of interval training.