Why Endurance Exercise Training Is Good for Fat Burning

What is endurance exercise?

Endurance exercise training occurs during repetitive prolonged exercise of so-called submaximal intensity.

Why submaximal intensity is good forfat burning?

Submaximal is an intensity of exercise that requires less than maximal oxygen uptake and it challenges the body to deliver an increased amount of oxygen to the tissues and utilize it there. As this kind of training proceeds, the body develops several kinds of adaptation aiming to the increase of its ability to utilize - "burn" - oxygen. This is why endurance training is considered the most efficient mean to burn fat and lose weight.

These adaptive changes occur mostly in the brain, muscles, capillaries, and the neuro-muscular junctions where the nerves carrying information from the brain contact muscle fibers.

Tissue adaptations or as they call them peripheral adaptations are such changes of structure and function of muscle that enhance its ability to burn oxygen and produce energy.

As a result of endurance training there is an increase in blood supply to the working muscle. An increased growth of capillaries in trained muscles and greater elasticity of the existing capillaries achieve this goal.

There also are important changes in enzymatic activities within muscle cells as well as an increased storage of glycogen in the muscles and increased fat mobilization from body's fat depots.

What are other major types of exercise training?

High-intensity short-term exercises (such as sprinting) as well as strength training cause improvements in performance, which are largely results of improved coordination. It does not directly increase the body's ability to burn fat. This is their major difference from the endurance training from the weight loss viewpoint.

In addition to the neural adaptations, strength training stimulates an increase in muscle size. This hypertrophy is mostly due to increased protein synthesis and is dependent upon many factors including sex and body type. It is not clear so far whether or not strength training is able to increase the number of muscle cells (hyperplasia.) There are however another aspects of muscle mass influence on metabolism and we'll talk about it later.

Endurance Training and Fatness

An excess of fat tissue - obesity - leads to the development of diabetes, an increased risk for heart disease, high blood pressure, arthritis, fat metabolism dysfunction, various cancers and all-cause mortality. The prevalence of obesity has risen dramatically since the 1970s, in parallel with a fall in daily energy expenditure of about 800 kcal.

Based on the principles of energy balance, a circumstantial evidence indicates that physical inactivity can be expected to promote obesity. However, surprisingly enough, firm scientific data are scarce.

In one nation-wide research trial, out of 3515 men and 5810 women studied in the USA over a 10-year, those who were sedentary were much more likely to gain more than 13 kg comparing with those who were. There are a few more similar studies supporting these findings.

What makes these results' interpretation so difficult is that the studies investigating the effects of exercise and diet on body weight and composition (BMR) are not easy to analyse. Energy intake, body fat status and distribution, and physical activity are difficult to quantify accurately due to 1) a lack of satisfactory control and 2) the fact that weight loss leads to "metabolic economy."

Nevertheless, it is quite safe to assume that exercise helps to protect muscle mass while promoting the fat loss though it is well known that exercise alone can reduce body weight less successfully than dieting alone.

Exercise and Inches Loss

So might the combination of exercise and dieting be expected to improve weight loss? Unfortunately, most data show only a slightly greater loss (2-3 kg) caused by the combination. When the negative energy balance is kept constant, diet, exercise, and diet plus exercise - all result in similar weight loss.

Good news is that the inclusion of exercise in a weight loss program results in greater "inches loss" - a greater @{fat loss }@and an increased lean tissue mass.

Energy costs of exercises (Calorie burning charts)

MET - metabolic equivalent (times the resting metabolic level)

1 mile = ~ 1.6 km

• Walking 6.5 km/h - 4 MET (metabolic equivalent, times the resting metabolic level)
• Running 11 km/h - 11 MET
• Cycling 21 km/h - 8 MET
• Swimming (front crawl, moderate) - 8 MET
• Tennis (singles) - 8 MET
• Aerobics (moderate) - 6 MET

Sources

• Ainsworth BE, Haskell WL, Leon AS et al. (1993) Compendium of physical activities: classification of energy costs of human physical activities. Medicine and Science in Sports and Exercise 25(1):71-80
• Blair SN, Kohl HW, Barlow CE, Paffenbarger RS, Gibbons LW and Macera C (1995) Changes in physical fitness and all-cause mortality. A prospective study of healthy and unhealthy men. Journal of the American Medical Association 273:1093-1098
• Poehlman ET (1989) A review: exercise and its influence on resting energy metabolism in man. Medicine and Science in Sports and Exercise 21(5):515-525
• Physical Activity and Health: A Report of the Surgeon General. (1996) Atlanta: US Department of Health and Human Services, Centres for Disease Control and Prevention, National Centre for Chronic Disease Prevention and Health Promotion