Can Exercise Really Make You Thin?
Gym memberships have risen from 23 million Americans in 1993 to 45 million Americans in 2009. The Minnesota Heart Survey asked people if they exercise regularly and the number who responded "yes" grew from 47% in 1980 to 57% in 2000. Yet the obesity rate in America continues on a dramatic climb: a third of Americans are obese and another third are overweight. So the questions has been posed: does exercise actually help people to lose weight?
These figures taken alone would indicate that exercise is not helping people to shed excess pounds. The problem might stem from the fact that burning calories during exercise can stimulate hunger, so in the time period following exercise, poor food choices may actually cancel out the weight loss from exercise. In other words, exercise won't help you to lose weight if you are consuming more calories than you burn. Going to the gym and running four miles will not suffice if you eat McDonald's on the way home.
A study conducted by Louisianan State University assigned 464 overweight women who didn't regularly exercise into four groups. Women in three of the groups were assigned to work out with a personal trainer for 72 minutes, 136 minutes and 194 minutes per week for six months. Women in the fourth group served as the control and were asked to maintain the lifestyle they had prior to starting the experiment. All of the women were instructed to not change their diet and to fill out monthly health questionnaires. The findings were surprising, because on average, the women in all four groups did lose weight. The groups who worked out with a trainer several days a week did not lose significantly more weight than the control group, and some women in all four groups actually gained weight, some more than ten pounds each. The control group may have lost weight because they were filling out the monthly surveys which may have made them more aware of poor eating habits. The researchers noted that the groups who were exercising were "compensating", and actually ate more during the study than before they started. They may have been hungrier from exercising, or they may have been rewarding themselves with food for a job well done.
After six months of working out, the women trimmed an average of one inch from their waist line, but lost no more body fat on average than the control group. Some people offer the reasoning that if you are exercising, then you are converting fat into muscle, and muscle does burn more calories than fat: a pound of muscle burns approximately six calories a day in a resting body while fat burns only two. This means that if you work out hard enough to convert ten pounds of fat into ten pounds of muscle, you could automatically burn 40 extra calories per day. However, that's not a large enough increase to justify doubling your food intake.
Part of the reason humans can not easily process extra calories is because we do not have "brown" fat. Brown fat is found in animals like mice, and helps to produce a protein that switches off mitochondria, which is what helps to turn nutrients into energy. Instead, the animals get warmer and as their temperature rises, calories burn off easily. When people eat extra calories, we instantly store most of the calories we don't need in our regular "white" fat cells.
Exercise has many great features: it enhances heart health and helps to prevent disease, and improves mental health and cognitive ability. Exercise doesn't need to be a hard core gym work out to be beneficial - simply becoming more active in the daily routine will benefit Americans greatly as they age. Buying a pedometer to make sure you are taking 10,000 steps a day is a way to start measuring if you are moving around enough. Simple activities like taking the dogs and kids on a long walk, gardening, walking up the stairs rather than the elevator, walking ten minutes on your lunch hour, going for bike rides and nature hikes, and playing in the park may not make you sweat, but have long term benefits for your health. Limit TV and computer time at home and play a board game to stimulate your mind instead.
The experts are still out on whether going to the gym and expending more energy in a little time would have more benefit to your health than moving frequently throughout the day. Most likely, placing lower amounts of more frequent stress on your muscles and body could have more positive outcomes for overall health. It is important if you are devoted to the gym and not getting the results you want to evaluate your eating habits. Start a food journal chronicling what you are eating and drinking, and at what times. Do this for a few weeks, and then review any extra, empty calories that are keeping you from reaching a fitness goal. Cut out sabotaging substances like soda, and replace with hot or unsweetened iced tea (add a lemon wedge for more flavor), replace your afternoon snack of chips and other processed foods with fresh fruits, dried fruits or some crunchy raw carrots. Keep late night snacking to a minimum, eat dinner at least 3 hours before going to bed, and eat smaller meals more frequently throughout the day. Most of all, keep a healthy mindset. If the research tells us anything at all, it's simply that those who truly embrace health will lose the weight!