I saw this article online and it really dampen my spirit since swimming is my favorite sport and I am trying to loose weight at the same time. Any comment??
SWIMMING IS NOT GOOD FOR WEIGHT LOSS
If you want to lose weight, lower cholesterol, or help to control diabetes, swimming is better than nothing, but not that much better (1).
A recent report from the University of Colorado shows that obese people who start a supervised swimming program do not lower their fasting blood sugar, insulin, total cholesterol, good HDL cholesterol and bad LDL cholesterol levels. They also did not lose weight or redistribute their body fat (2).
These results are different from people who start land-based sports such as running, aerobic dancing, racquetball and cycling. When you exercise on land, your body is surrounded by air which insulates you, causing your body to retain heat and your body temperature to rise for up to 18 hours after you finish exercising. Increased body temperature speeds up your metabolism and helps you to lose weight and lower cholesterol. On the other hand, when you swim, your body is surrounded by water which is an excellent conductor of heat away from your body, preventing your body temperature from rising. If you want to lose weight by swimming, the best way is to do it is by using a swimming machine on dry land.
I'm Dr. Gabe Mirkin on Fitness.
1) H Tanaka, DR Bassett, ET Howley. Effects of swim training on body weight, carbohydrate
Individual examples are fine, but I think it would be more useful if we can determine where the studies went wrong. (And if they didn't, then that is important!)
I decided to go looking for the articles cited. The library I went to does not carry those journals. The full articles are available on the web, but for a hefty fee. :( I am going to make some judgements based on what information I have (the abstracts). If someone else has the entire article, hopefully they will comment.
1- Original article
2- Colorado study in 1997, abstract
3- Journal of Sports Medicine 1987, abstract
Lets start with oldest to most recent article, and the points that jumped out at me...
Article 3: Are they comparing apples to oranges?
- The exercise was listed as 60 minutes daily, for 6 months, but I can't judge the intensity level. You are going to get a decent workout with a "brisk walk", the question is how "brisk" was the swim?
- No dietary restrictions. This would have been a lot more interesting: did their food intake increase as they did more swimming?
- They compared two leg-based land exercises, to a mostly upper-body aquatic exercise. I'm guessing that leg strength increases with body weight (even for sedentary people), but that upper body strength probably doesn't. It would have helped if they had an upper-body land group (rowing machine) and a leg-centric aquatic group ("walking" in a pool with a life vest??), to make sure all of the bases are covered.
Article 2: Much better abstract/study! :)
- They start off by stating that there was no data studying the efficacy of swimming for treatment of obesity and cardiovascular risk factors, as opposed to many studies for land-based exercise.
- The exercise was 45 min a day, 3 days a week, for 10 weeks, at 60% of maximal heart rate. (I don't know about you, but I can get 60% on an easy recovery swim.)
- The study found a significant improvement in resting and submaximal heart rates, lactic acid concentrations, and perceived exertion. If swimming affects your heart rate, can you really use that as your guide to how hard you are training? (I'm not sure what they could use, if not heart rate, but I think this should be noted.)
- The last statement is that "swim training of the duration, frequency, and intensity used in the the present study" did not help. It did not say that swimming (of any kind) will not help. I don't have the citation, but I remember a study that showed that low-intensity aerobics had no improvent in body fat or aerobic capacity (but high-intensity did).
Article 1: You need more than 1 data point to determine the slope of a line!
- With only two studies in the last 16 years, I think this is a pretty wild overstatement. I think a better statement would be "a low-intensity swim program with unrestricted diet fails to improve (blood factors)".
- As Kevin pointed out, that body temperature thing came out of left field. (Is that "Kevin in Maryland" or "Kevin in medicine"?)
- To be nit-picky, the Colorado article was in the June 1997 issue, not the July 1997 issue. It pays to be accurate with your citations.
Individual examples are fine, but I think it would be more useful if we can determine where the studies went wrong. (And if they didn't, then that is important!)
I decided to go looking for the articles cited. The library I went to does not carry those journals. The full articles are available on the web, but for a hefty fee. :( I am going to make some judgements based on what information I have (the abstracts). If someone else has the entire article, hopefully they will comment.
1- Original article
2- Colorado study in 1997, abstract
3- Journal of Sports Medicine 1987, abstract
Lets start with oldest to most recent article, and the points that jumped out at me...
Article 3: Are they comparing apples to oranges?
- The exercise was listed as 60 minutes daily, for 6 months, but I can't judge the intensity level. You are going to get a decent workout with a "brisk walk", the question is how "brisk" was the swim?
- No dietary restrictions. This would have been a lot more interesting: did their food intake increase as they did more swimming?
- They compared two leg-based land exercises, to a mostly upper-body aquatic exercise. I'm guessing that leg strength increases with body weight (even for sedentary people), but that upper body strength probably doesn't. It would have helped if they had an upper-body land group (rowing machine) and a leg-centric aquatic group ("walking" in a pool with a life vest??), to make sure all of the bases are covered.
Article 2: Much better abstract/study! :)
- They start off by stating that there was no data studying the efficacy of swimming for treatment of obesity and cardiovascular risk factors, as opposed to many studies for land-based exercise.
- The exercise was 45 min a day, 3 days a week, for 10 weeks, at 60% of maximal heart rate. (I don't know about you, but I can get 60% on an easy recovery swim.)
- The study found a significant improvement in resting and submaximal heart rates, lactic acid concentrations, and perceived exertion. If swimming affects your heart rate, can you really use that as your guide to how hard you are training? (I'm not sure what they could use, if not heart rate, but I think this should be noted.)
- The last statement is that "swim training of the duration, frequency, and intensity used in the the present study" did not help. It did not say that swimming (of any kind) will not help. I don't have the citation, but I remember a study that showed that low-intensity aerobics had no improvent in body fat or aerobic capacity (but high-intensity did).
Article 1: You need more than 1 data point to determine the slope of a line!
- With only two studies in the last 16 years, I think this is a pretty wild overstatement. I think a better statement would be "a low-intensity swim program with unrestricted diet fails to improve (blood factors)".
- As Kevin pointed out, that body temperature thing came out of left field. (Is that "Kevin in Maryland" or "Kevin in medicine"?)
- To be nit-picky, the Colorado article was in the June 1997 issue, not the July 1997 issue. It pays to be accurate with your citations.
