Interval Training and it’s
relationship to medicine and fitness
Interval training has been the basis for athletic training routines
for many years. It involves alternating short, fast bursts of intensive
exercise with slow, easy activity. "Fartlek," as it was termed, was
casual, unstructured training that perfectly fit it's English
translation: "speed play." Interval training today involves highly
sophisticated methods of structured training for athletic performance
enhancement. Physiologists and trainers have designed interval programs
that are specifically suited to individual athletes. These sessions
include precisely measured intervals that match the athlete's sport,
event and current level of conditioning. Often the appropriate intensity
and duration of the intervals is determined by the results of anaerobic
threshold testing (AT) that includes measuring the blood-lactate of an
athlete during intense exercise.
How Interval Training Works
Interval training 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. This
repetitive form of training leads to the adaptation response. 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.
According to the American College of Sports Medicine, more calories
are burned in short, high intensity exercise. If you are counting
calories burned, high intensity exercise such as intervals are better
than long, slow endurance exercise, but you may pay a price. You don't
need to be a world-class athlete and have sophisticated blood analysis
to take advantage of the benefits of interval training. The standard
"speed play" training of fartlek works well for the rest of us. This
type of interval work is based upon your subjective needs. Simply pay
attention to how you feel and set your intensity and duration
accordingly.
Precautions for Safe Interval Training
- Warm Up before starting intervals
- Assess current conditioning and set training goals that are within your ability
- 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 intensity or duration, but not both at the same time
- 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 You
can take a more scientific approach to interval training by varying
your work and recovery intervals based on your pre-determined goals.
Here are the four variables you can manipulate when designing your
interval training program:
- Intensity (speed) of work interval
- Duration (distance or time) of work interval
- Duration of rest or recovery interval
