A Word On Fat
Facts about Fat
How much is too much body fat ?
It is generally accepted that men should have less than 18% total body fat and women 23% or less, However, experts suggest that an excess is not particularly hazardous to health until an individual accumulates 35% and 40% total body fat respectively. Such levels definitely constitute obesity and potentially, if not most probably, have a detrimental effect on one’s health. Body fat percentage <fatcent.htm> can be determined using a pair of callipers.
Where does body fat come from?
Fat is produced by the body when an excess intake of calories in the form of food or drink occurs. When the diet provides the body with more calories than it needs for general maintenance and its current level of physical activity, this excess energy is stored in the form of body fat.
How do I lose excess fat?
Put simply, the removal of excess fat is by a reversal of the bodily processes which store excess energy, if an individual burns more energy than he or she is consuming, the extra energy stored in the body will be removed to be broken down for physical activity.
How does exercise affect body fat?
An increase in regular exercise will help to increase your calorie expenditure. The more physical activity you do, the more calories you will burn. Accordingly, if you increase your physical activity, and do not increase your intake of food, you will draw the extra energy needed from your stored body fat.
Why do gains in weight always seem to go on the same place?
One’s body tends to deposit fat according to your individual genetic code. In other words, hereditary characteristics dictate areas in your body which accumulate fat. If you are a typical female you will accumulate fat around your thighs and hips. Typically males accumulate fat around the midriff and lose it there last
Can I get fat off from a specific part of the body ?
Unfortunately not, there is no such thing as “spot reduction”. If you exercise a particular part of the body, muscle tissue under the fat will become firm and make the overall appearance of that region look better. However, such specific exercise will not reduce the quantity of fat within the area. Thus simply by jogging one will not just reduce the fat around the legs and hips, the fat providing energy for this activity may be coming from the stomach, chin, back etc.
How many calories will it take to lose one pound of fat?
A calorie is a unit of energy, the deficit needed to lose one pound of fat being approximately 4000 calories. This “rule of thumb” may vary considerably depending on the nature of the fat lost, however, for long term weight loss this figure is probably accurate.
Can I sweat off excess weight in a steam room or sauna?
Remember you are not trying to lose weight but fat. There is a real difference between the two. Weight could be fat, water or even muscle tissue, whereas fat is fat. The loss of weight through excess sweating as experienced in the sauna/steam room is not fat but water. Such weight returns immediately you consume fluid. Consequently if you lose say two and a half pounds in a session in the steam bath you will replace it with approximately the next two pints of water drunk (one pint of water weighs a pound and a quarter). However and obviously more worrying is that if the fluid loss is replaced by a high calorie drink you may end up gaining fats as a result of your weight loss attempt.
What are Essential Fat & Storage Fat?
The essential fat, required for normal physiological functioning, consists of fat stored in the marrow of bones, heart, lungs, liver, spleen, kidneys, intestines, muscles and lipid rich tissues of the central nervous system. In females the extra 9% of sex specific fat is required for childbearing and other hormonal related functions.
In addition to essential fat deposits, storage fat consists of fat accumulation in adipose tissue. Men and women have similar quantities of storage fat - on average 12% for men and 15% for women.
Fat provides all your energy
Let us consider the other extreme. If fat alone was meeting all your energy needs, you would not be breaking down carbohydrate during your workouts and as a result your leg muscles would be amply and permanently stocked with glycogen (assuming, of course, that your diet contained a normal carbohydrate content). Each time you ate, the carbohydrate from your meal would be processed and transported to your muscles. Your muscle cells would say, ‘No thanks, I don’t need more carbohydrate, I’m already full.’ The surplus carbohydrate from your meal would then be converted to, you guessed it, fat. Looks like a no win situation - as fast as you burn fat off it is replaced.
Effective way to lose fat
Most exercisers are time constrained to some degree and do not have hours to spend on low intensity sessions. When time is limited, there is little reason to train in your Fatmax Zone. If your overall goal is to get leaner, the bottom line is that calorie burning is the best way to achieve it.
The most effective way to lose body fat is to burn slightly more calories than you take in, and to continue this negative energy balance over an extended period of time.
Low intensity sessions to burn off fat
There are two key variables that we need to know:
Fatmax - the exercise intensity at which the highest rate of fat oxidation occurs
Fatmax zone - the range of exercise intensities in which the fat oxidation rates remain within 10% of Fatmax
Researchers from Birmingham University’s Human Performance Laboratory attempted to pinpoint the exercise intensities at which fat metabolism is maximised in a study of 18 male endurance cyclists with a training background of at least three years. Their work found that the Fatmax Zone is between 68% and 79% MHR
Alternative research has suggested that when you cycle, swim, row or run at a modest intensity of only 50% VO2max (about 69% MHR), fat provides about 50% of the calories you need to keep going for the first hour or so. If you keep going after that, fat becomes even more generous, providing around 70% of the total energy after two hours and 80% or more if your work duration exceeds three hours. If you increase the intensity then the Fat contribution decreases - at 75% VO2max fat provides 33% of the energy
High Intensity sessions - just as good!
The implication from all this research is that if you wish to burn maximum amounts of fat then you should train in the 68 to 79% MHR window. The reality is that if you train at higher intensities you can burn just as much fat - you cannot be serious - read on
If you cycled along at 50% VO2max, fat would provide about 50%, on average, of the energy you needed to keep going. If you cycle along at 75% VO2max, fat would provide 33% of the required calories. Thus, the slower workout sounds better from the fat breakdown perspective - or does it?
A moderately fit athlete exercising at 50% VO2max generally consumes about 220 calories during a 30 minute workout. If the same athlete works out at 75% VO2max, 330 calories are burned during the same period. Of course, 50% of 220 calories and 33% of 330 calories yield an identical number of calories coming from fat - 110 calories.
