Wednesday, November 21, 2007

Burning fat after exercise.....

Here is a study which supports the idea of "afterburn" or turbulence created by training. When you train, even the muscles that you are not working burn more calories after exercise. The harder you train, the greater that effect

Oxygen Consumption in Nonexercising Muscle after Exercise.
Integrated Arts and Science, Okinawa National College of Technology, Okinawa, Japan.

Little is known about the effect of exercise intensity on post-exercise oxygen consumption in non-exercising muscle. This study examined the effect of exercise intensity on muscle oxygen consumption (V.O (2mus)) in non-exercising forearm flexor muscles (nonexV.O (2mus)) after cycling exercise. Eight healthy male subjects performed 20 min of cycling exercise at 30 %, 50 %, and 70 % of maximal oxygen consumption (%V.O (2max)) on separate days. The nonexV.O (2mus) values at rest, at the end of exercise, and during recovery after exercise were measured by near-infrared spectroscopy. V.O (2mus) was determined using the rate of decrease in oxygenated hemoglobin during arterial occlusion. The nonexV.O (2mus) at the end of exercise significantly increased by 1.3 +/- 0.1, 2.0 +/- 0.3, and 2.2 +/- 0.3-fold over resting values at 30 %, 50 %, and 70 % V.O (2max), respectively. NonexV.O (2mus) returned to the resting value after 3 - 5 min of recovery and then showed no significant change for 120 min after exercise at all exercise intensities. NonexV.O (2mus) at the end of exercise at 70 % V.O (2max) was significantly higher than that after exercise at 30 % V.O (2max). These results show that 20 min of cycling exercise induced an increase in nonexV.O (2mus) and that higher intensity exercise produces a larger increase in nonexV.O (2mus) after exercise.

Alwyn Cosgrove explains the theory behind all this here.

The key with anaerobic training is what is known as EPOC. Anaerobic exercise burns a ton of calories while you are performing it. However, the metabolism remains elevated following this type exercise.

This was, at one time, referred to as the oxygen debt, but is now referred to as the excess post-exercise oxygen consumption (EPOC).

The recovery of the metabolic rate back to pre-exercise levels can require several minutes for light exercise (aerobic training), several hours for very heavy exercise (anaerobic cardio training), and up to 12 to 24 hours or even longer for prolonged, exhaustive exercise (interval training or circuit weight training).

The EPOC can add up to substantial energy expenditure when totaled over the entire period of recovery. If the oxygen consumption following exercise remains elevated by an average of only 50 ml/min or 0.05 liter/min, this will amount to approximately 0.25 kcal/min or 15 kcal/hr.

If the metabolism remains elevated for five hours, this would amount to an additional expenditure of 75 kcal that would not normally be included in the calculated total energy expenditure for that particular activity.

This major source of energy expenditure, which occurs during recovery, but is directly the result of the exercise bout, is frequently ignored in most calculations of the energy cost of various activities.

1 comment:

Chris said...

Alwyn Cosgrove has just pointed towards this same research: