Why do women usually loose on Biggest Loser Why are the fatter people a threat? How does VO2 max exercise physiology come into play in this game? How come some people seem to consistently do better in the biking and running challenges?
VO2 max (VO2) is a measure of a person’s ability to transport oxygen while exercising; (ml Oxygen per kilogram of their weight per minute).. It is very highly corelated to running speed ability and ability to burn calories relative to time when exercising. There are genetic, age, training and gender factors in a person’s VO2 measurment.
Points to consider on contestant winnings:
Women usually have a lower VO2 then men, by 50%, so can only run (or do other exercises) at a slower speed and burn less calories per minute on average
but women generally have better endurance then men (why they win in Survivor when they have to hang onto things) so women in theory could just exercise longer to burn the same calories; however there are only so many hours in a day. Some reports say that the contestants exercise 6 hours a day 7 days a week, but I am not sure how accurate that is.
Some contestants have the ability to burn more calories then others at the start of the show; VO2 values vary from 20 to 75 for sedentary people, which the contestants are at the start of the show. For women the range is roughly 20 to 45; for men it is rougly 35 to 66. So you can see that men have a distinct advantage from the get go. A contestant with good genetic VO2 for their gender could burn up to 2.5x more calories per unit time exercised per pound of body from the get go then the theoretical worst contender!! I wonder if any obesity research is being done on this issue.
As you train, you soon get to your max VO2 max for your personal ability of 50% higher than sedentary (one reference said it takes about 2 years for people who train an hour a day another said a few months so I am not sure on this). Some contestants may not get to their max VO2 max as fast as other due to mental factors, genetic factors, illnesses, not knowing how to exercise properly or being over trained or injured by the trainers
The longer you train the longer you can train at a higher heart rate so the people who train less due to injury, mental block, inexperience or possibly diseases that cause exercise insufficiency such as heart disease, high blood pressure, diabetes, hypothyroidism, genetic inability to process fat and other metabolites normally, etc. will not be able to train at that sustained high heart rate as fast in the game as the other contestants.
Some contestants weigh a lot and so are not able to loose all the weight they need to in the 5 (?) months that the show runs; others run out of fat to loose and so can’t keep losing the whole show.
The smaller contestants have to loose less weight but also burn less when they run just as fast as a heavier person. For example: how many calories you burn at a given speed on a treadmill is directly proportional to your weight. VO2 takes weight into account.
VO2 max goes down as we age so younger contestants would have an advantage over older. You can see this effect on the standard heart rate chart hung in most gyms.
The most you can improve from sedentary to best VO2 max during the game is roughly 50% increase. The average VO2 for sedentary Americans (male and female) is 35. So say the women (probably all contestants are naturally lower in ability to get to VO2 max compared to average which is why they are so fat) start at 25; they can only go to 37.5. Let’s say a man starts at average 35 (which is lower than average for men only) and then can get to 50% more or 52.5. They can then burn 40% more than the women even if they are genetically worse at burning than the women in relative terms.
Granted, this does not take weight into account which the contest does, so I am not sure if percentage wise it makes a difference since most of the men are much heavier than the women (may explain why the shorter men do better???). Men are often around 400# to start and women often 200# to start so men have to loose 2x as much as women because of the percentage rule.
You can see from my calcs that these assumptions are pretty close to what we see based on a reported 6 hours a day, 7 days a week exercise schedule. At the end the weight loss calculated is higher than what we see, possibly as a result of the contestants not being pushed as hard or because of accummulated injuries from working out so much.
Muscle increase: some people are hard gainers meaning they don’t easily put on pounds of muscle. Others are medium or easy gainers. Many of the contestants appear to be very stocky, easy gainers. So they are piling on pounds of muscle…easily a pound a week, as they are loosing fat. Since the game only counts pounds lost, not fat lost, the easy gainers may end up behind. Their increased muscle WILL increase their basal metabolic rate however, so that may work in their favor as they sleep. I am guessing that the moderate calorie restriction the contestants do compensates for most of their muscle gains.

