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Below is a summary and overview of the 8-second fat loss study, the FEM trial, and the Optimal Fat Loss program at UNSW
Steve Boutcher PhD, FACSM
Director of Fat Loss Laboratory, Faculty of Medicine, UNSW 28/1/2007
1. 8-second fat loss study. Forty five women aged 20 years with a BMI of 23.5 kg/m2 were randomly assigned to a high intensity intermittent exercise (HIIE) condition, a steady state exercise (SSE) condition, or a control condition. Body fat was assessed by DEXA, pre and post after the 15 week program. Blood was taken before and after to examine possible changes in cholesterol, HDL, LDL, triglycerides, insulin, c-reactive protein, glucose, adiponectin, leptin, and cortisol. The HIIE program consisted of an 8-second sprint immediately followed by 12 seconds as slow as possible pedaling. Women performed this continuously so that they completed 60 sprints in the 20-minute exercise bout. There were three exercise sessions per week; 45 overall. Women started the HIIE condition for only 5 minutes the first week and then built up the number of minutes and intensity of sprint. Intensity was assessed through a maximal oxygen uptake test performed previously so that the workload at an respiratory exchange ratio (RER) of .93 was used for each individual woman. This equated to about 90% of flat out sprinting for most women. All women were completing the 20 minutes of HIIE within 6 sessions (2 weeks). Most women performed at a pedaling rate of 100-120 at a resistance of .5 to 1 kg. The SSE consisted of three 40-minute continuous stationary bike exercise at 60% of peak oxygen uptake. Both conditions had a 5-minute warm-up and a 5-minute cool-down. RESULTS: SSE women increased body fat slightly by .5 kg whereas HIIE lost 2.5 kg. The women who lost the least fat in the HIIE group were the leanest with an average BMI of below 20 kg/m2. When these women were removed average fat lost for the rest of the women was 3.9 kg. Two women in the group lost between 8-9 kg of fat. The fat loss in the HIIE was disproportionate with the women losing more fat off their legs than their arms. HIIE women also lost significant fat from their abdomen which suggests that this type of exercise may be particularly successful with men. HIIE women decreased fasting insulin by 31% and SSE women by 8%. Both exercise groups increased their aerobic fitness; the SSE by 19%, and surprisingly, the HIIE group by 26%. Blood lipids did not change (all were normal at pretest) and we haven’t finished analyzing other blood variables yet. In summary, HIIE women lost about three times more fat doing about half the exercise. HIIE also had a dramatic effect on fasting insulin levels. This research was one study in Gail Trapp’s PhD program recently completed at UNSW. If you are considering trying this type of program it would be beneficial to touch bases with an accredited EP (Exercise Physiologist) to check out your suitability. You should also check it out with your GP if you have any risk factors (e.g., on any medication) or health problems.
Co-researchers in the fat loss research program are: Gail Trapp: PhD UNSW; Sarah Dien: PhD candidate UNSW; Professor Don Chisholm: Garvan Institute; Judy Freund: St Vincents Hospital
2. The FEM Trial: HIIE is only one important component of an optimal fat loss program. In three weeks time we are starting the FEM trial which represents Fish oils, Exercise, and a Mediterranean diet. We believe this combination will have a significantly greater effect on fat loss and metabolic stability than HIIE alone. One hundred women will undertake a 12-week program consisting of supervised HIIE, fish oil supplement, and a Mediterranean diet at UNSW. We plan to start another FEM trial later this year focusing on obese children. Thus, the plan is to undertake a 12-week “kickstart” program to normalize women’s body weight and metabolism in as brief a time as possible. This is Phase 1 of the optimal fat loss program. Phase II of the program will be continuation of the diet and fish oil with the HIIE and other exercises being home based. If you are female and aged between 18 and 30 years and have a BMI of over 25 kg/m2 you may be eligible for this trial. If interested contact Sarah Dien who is the FEM trial coordinator:
office phone: 02 9385 8710; email: sarah.dien@unsw.student.edu.au
3. Optimal fat loss program at UNSW: based on our research we conduct optimal fat loss programs in the Lifestyle Clinic at UNSW. We believe that the optimal fat loss should be based around lifestyle change and the FEM components described above plus other components such as stress management and resistance exercise. The most important aspect of our approach is that there is no one perfect exercise or diet program for everyone. Thus, each fat loss program is personalized. This program offers a variety of options and clients can come under MediCare and certain private health funds. Clients can carry out supervised HIIE in the Clinic if they so choose. To find out more about the Clinic check out: www.lifestyleclinic.edu.au. To make an appointment ring: 02 9385 3352. If you have problems you can email me: s.boutcher@unsw.edu.au
4. barriers to fat loss: will you lose fat if you carry out a program as described above? Maybe, however, not all individuals will lose fat. Losing fat is not simply brought about by eating less and exercising more. We know this combination is not particularly successful. The design of fat loss programs should be based on an in-depth examination of many individual factors that may hinder or prevent the body from burning fat. For example, birth weight, muscle fibre type, mitochondrial inefficiency, inflammation status, free radical status, adipocyte and muscle cell insulin resistance, resting metabolic rate, virus history, quality of sleep, amount of daily stress, ethnicity, weight cycling history, and many more factors effect our ability to lose fat. These factors should be assessed by qualified individuals. Also many of the “facts” we hear about weight loss are myths. For example, the evidence is overwhelming that starvation diets make people fat and obese. They also bring about more lifestyle diseases such as heart disease. Another myth is that eating fat makes you fat or eating a low fat diet makes you thin. In our Mediterranean diet, clients typically will eat more fat and more calories. However, the “fats” are good fats called monounsaturated and polyunsaturated fats which are found in fish and nuts. The most important message is to eat a lot of unprocessed foods such as fruits and vegetables. Don’t worry about having to learn to read food labels but eat foods that don’t have a label! In general, these foods contain a variety of “phytonutrients” which directly or indirectly turn on fat burning in fat cells. The data supporting the ability of the Mediterranean diet to lose weight and reduce heart and other disease is extremely strong. So people should not starve themselves but should eat unprocessed foods that excite fat burning. Processed foods, in general, produce the opposite effect by turning on fat storage. They also make many cells operate inefficiently resulting in overweight and problems such as high cholesterol levels. Fat loss programs are best done under the supervision of a team of professionals so that clients do not waste energy and money carrying out programs that will not work because their bodies have been programmed to store fat rather than to burn fat. Thus, we believe the key to fat loss is to adopt a way of life that allows your cells to burn fat.
5. more information in this area: our articles on sprinting fat loss are currently under journal review. When published they will be displayed on our website. Hopefully, within a month. The only other article, to our knowledge, directly on intermittent sprinting and fat loss is:
Tremblay, A. et al. (1994). Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism, 43, 814-818.
A really good book about metabolism and fat loss is:
Hyman, M. (2006). Ultra-metabolism. Schwartz Publishing. ISBN: 978 1 86395 318 4
“The key to fat loss is to adopt a lifestyle that allows fat cells to function as they were designed”
Good luck:
Steve Boutcher PhD, FACSM
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