High Intensity Workouts For Weight Loss & Fat Burning

Short high intensity workouts have long been associated with increases in muscle mass but not weight loss, and more specifically fat burning. Continuous aerobic exercise has been the standard recommendation for fat loss in conjunction with some form of resistance training, however research has shown that the standard recommendation of more exercise is better1 for weight loss and overall health may be fundamentally flawed. Instead, short high intensity workouts do appear to be more efficient at burning fat and increasing overall metabolism.2

One study involving 45 overweight female participants conducted at the University of New South Wales in Australia had some interesting findings regarding short high intensity workouts and weight loss. Using a high intensity interval program, it was found that the women burned fat at a rate three times higher than what is normally seen from aerobic exercise. The high intensity workouts consisted of an all out eight second sprint, with only intervals of only 12 seconds of rest in between sprints. The entire high intensity training exercise lasted for 20 minutes. The second group exercised on stationery bicycles at a consistent pace in keeping with traditional aerobic exercise guidelines for 40 minutes. After 15 weeks, researchers found that the women in the high intensity workout group lost three times more weight than those who rode the bicycles for twice as much time.

The high intensity workout group lost an average of 5.5 lbs of body fat, which correlated with a 11.2% decrease in their overall body fat levels while the other group doing conventional steady state aerobic workouts per week for a longer period of time saw an increase in their overall body fat levels!

High Intensity Workouts Promote Weight Loss Through An Elevation In Resting Metabolism

Scientists attribute the fat burning effect of high intensity workouts to what they call ‘the afterburner effect’ or more precisely, excess post-exercise oxygen consumption (EPOC). While recovering from the effects of exercise, there is an increase in the amount of oxygen (EPOC) used to restore the body to a resting state of homeostasis and adapt it to the exercise just performed. These processes include balancing of hormone levels, replenishing depleted fuel stores, cellular repair, innervation and anabolism. EPOC is accompanied by an elevation in the amount of fuel your body burns. After exercising, fat stores are broken down and free fatty acids are released into the blood. During the recovery phase, the direct oxidation of free fatty acids as a fuel source and the energy consuming re-conversion of free fatty acids back into fat stores both take place all of which is seen as an increase in metabolism and fat burning after exercise.3,4,5

For exercise regimens of comparable duration and intensity, aerobic exercise burns more calories during exercise, but the difference is offset to a degree by the higher increase in caloric expenditure that occurs during the EPOC phase after high intensity anaerobic resistance exercise. High intensity workouts have been found to elevate metabolic rates long after the period of exercise has been completed, thus the body burns more calories and at a higher rate long afterwards. This increase was first thought to occur only with aerobic exercise, but further research has shown that it actually occurs more prevalently in high intensity anaerobic workouts.2

High Intensity Workouts Are A Practical, Modern Weight Loss Solution.

Science aside, on a practical level, as many can attest to the frustration that comes from employing a regime of aerobic exercise for weight loss. Prolonged aerobic, and for that matter, anaerobic training do not create the tremendous changes in body fat that most people expect,  while those engaging exclusively in shorter high intensity workouts involving serious weight lifting tend to be leaner and more muscular than their aerobic training counterparts. The analogy often cited is that of the marathon runner and the sprinter. Sprinting requires high bursts of muscular activity (anaerobic exercise) while long distance running involves steady state aerobic activity for long periods of time. Sprinters are known for their toned, chiseled and well sculpted physiques with minimal body fat levels. Elite long distance runners tend to be low on muscle mass, even though they may be low in body fat and thus do not have the impressive bodies sported in the sprinting arenas. When it comes to reducing body fat, short high intensity workouts may well be the answer to our growing obesity problem, and the perfect solution to today’s hectic lifestyles.

References

1. Division of Nutrition, Physical Activity and Obesity, National Center for Chronic Disease Prevention and Health Promotion

2. Impact of exercise intensity on body fatness and skeletal muscle metabolism. Tremblay, A. et al., Physical Activities Sciences Laboratory, Laval University, Quebec, Canada Metabolism.1994; 43(7): 814-818

3. Bahr R (1992). "Excess postexercise oxygen consumption--magnitude, mechanisms and practical implications". Acta Physiologica Scandinavica. Supplementum 605: 1–70. PMID 1605041.

4. Bahr R, Høstmark AT, Newsholme EA, Grønnerød O, Sejersted OM (September 1991). "Effect of exercise on recovery changes in plasma levels of FFA, glycerol, glucose and catecholamines". Acta Physiologica Scandinavica 143

5. Bielinski R, Schutz Y, Jéquier E (July 1985). "Energy metabolism during the postexercise recovery in man". The American Journal of Clinical Nutrition 42

Additional Studies On Low Volume, High Intensity Workouts For Weight Loss & Increasing Muscle Mass:

High-intensity Interval Training: A Time-efficient Strategy for Health Promotion. Martin J. Gibala, PhD, Department of Kinesiology, McMaster University, Ontario, Canada Current Sports Medicine Reports 2007, 6:211-213

Summary:

A commentary by high intensity workout researcher, Dr.Martin Gibala's examining rapid adaptations in exercise capacity and aerobic energy metabolism after short-term high intensity training. Using the Wingate Test, which involves all out cycling against high resistance he explores the effect of high intensity training on exercise capacity and skeletal muscle adaptations.

Impact of exercise intensity on body fatness and skeletal muscle metabolism. Tremblay, A. et al., Physical Activities Sciences Laboratory, Laval University, Quebec, Canada Metabolism.1994; 43(7): 814-818.

Summary:

This study had participants spilt into 2 groups: one group doing 20 weeks of steady state type aerobics and the other group did 15 weeks of high intensity interval training. The second group exercised for 5 less weeks and expended 48% less calories per session, but burned 900% more fat than the first group. It was concluded that compared to moderate-intensity endurance exercise, high- intensity intermittent exercise causes more calories and fat to be burned following the workout.

Related Articles On High Intensity Workouts:

High Intensity Workouts & Bone Density

High Intensity Workouts & Abdominal Fat

High Intensity Workouts & Weight Loss- 100 lb Weight Loss Cass Study

Aerobics A Bad Idea For Fat Loss

High Intensity Workouts Incorporated Into Chi Kung Meditation

References

1. Powers M (2005). "Performance-Enhancing Drugs". in Deidre Leaver-Dunn; Joel Houglum; Harrelson, Gary L.. Principles of Pharmacology for Athletic Trainers. Slack Incorporated. pp. 331–332. ISBN 1-55642-594-5.

re.