Voor diegenen die willen gaan afvallen, en denken nu het zomer is hiervoor lekker te kunnen gaan zwemmen het volgende:
Uit onderzoek blijkt dat zwemmen niet helpt om af te vallen. Tenminste, fietsen/ lopen e.d. is beter.
http://www.ncbi.nlm.nih.gov/entrez/...ed&dopt=Abstract&list_uids=3618879&query_hl=1
1: Am J Sports Med. 1987 May-Jun;15(3):275-9.
Related Articles, Links
Weight loss without dietary restriction: efficacy of different forms of aerobic exercise.
Gwinup G.
Since obese patients with orthopaedic disabilities are often advised to undertake swimming as a part of a weight loss program, the effect of swimming on body weight was systematically studied. Minimally to moderately obese, otherwise healthy young women seeking to lose weight through a program of exercise without dietary restrictions were randomly assigned to one of three groups in which only the type of daily exercise was different. The three types of exercise were brisk walking, riding a stationary cycle, and swimming laps in a pool. All women slowly but progressively increased the time spent in daily exercise to 60 minutes. After 6 months or slightly longer, the women assigned to walking lost 10% of initial weight, the women who cycled lost 12%, but the women who swam lost no weight. The thickness of the subcutaneous panniculus over the middle of the extensor surface of the upper arm was measured using a Lang skin-fold caliper (Graham Field Co, New York, NY) and showed equivalent substantial reductions in the walkers and cyclists, but no change in the swimmers. The results of this study show that both walking and cycling are effective methods of reducing body fat, but that swimming is not.
Publication Types:
Clinical Trial
Randomized Controlled Trial
PMID: 3618879 [PubMed - indexed for MEDLINE]
Helaas is er nog geen verklaring hiervoor.
http://www.sportsci.org/jour/sportnutr.html#fat
en op bovenste link klikken
Ondanks gelijke calorie-inname en energieverbruik, hebben zwemmers meer vet dan hardlopers/fietsers.
· Index
SWIMMERS: Body fat mystery!
Louise Burke, Australian Institute of Sport, Canberra, Australia
Swimmers, especially female swimmers, face an energy balance conundrum. Elite swimmers typically undertake 4000-20,000 m per day in training, burning thousands of calories. However, the typical body fat levels of these athletes are significantly higher than runners or cyclists who expend similar or even smaller amounts of energy in their training. Many female swimmers have fought well-publicized battles with their body fat levels and with their coaches! They are generally prescribed "land training" (running or cycling) in addition to their many laps of the pool in the belief that it is a necessary treatment to produce lower skinfold levels.
Do energy discrepancies really exist in swimming? Why do swimmers seem to have drawn the short straw of body fat management? The following theories have been suggested:
Swimmers have higher energy intakes than other athletes and eat more energy than they expend. It has been suggested that swimming doesn't cause the appetite drop that accompanies heavy running and cycling training. Many people observe that they feel like "eating a horse" after they have finished a swim training session, and may overcompensate for the energy they have just burned. Some research suggests that this is due to the cool temperatures in which swimmers train. By contrast, runners and cyclists usually experience an increase in body temperature during training, which may serve to suppress appetite - at least in the short term.
Swimmers are less active outside their training sessions. They are so tired from the hours spent training that they sleep, sit or otherwise avoid any real energy expenditure outside their sessions.
Two studies from Costill's Human Performance Laboratory at Ball State University have tried to address the energy balance oddity of swimmers. Jang et al.(1987) attempted to gain a crude measure of daily energy balance by comparing collegiate swimmers and collegiate distance runners. Ten athletes of each coïtus from each sport participated in the study. The findings: runners had lower body fat levels than swimmers (7% v 12% for male runners v swimmers, and 15% v 20% for females). All subjects kept detailed 3-day food records, and 1-day activity records were kept by half the subjects in each group. These records noted the amount of time each individual spent sleeping, sitting, walking, standing or training. The energy cost of these activities was estimated individually for each athlete by duplicating the activity in the laboratory and collecting oxygen consumption data. This factor multiplied by the time spent in each activity produced an estimate of total daily energy expenditure.
Results showed that both groups reported similar daily energy intakes: 3380 kcal and 3460 kcal for male swimmers and runners; 2490 kcal and 2040 kcal for female swimmers and runners, respectively. Estimated energy output was in agreement for each group, with the values for the groups of male athletes being roughly equal and similar to their reported intake. The female swimmers had a higher energy expenditure than female runners, and in fact were in slight negative energy balance. These results were not helpful in finding or explaining an energy dilemma, or major differences between types of athletes. The theories above might explain the problems experienced by some individual swimmers, but the theories were not supported by evidence from the study.
One of the limitations of this study is that each method of measuring energy balance is subject to considerable flaws. It is almost impossible to measure usual energy intake from diaries. Apart from the errors in translating descriptions of food into calorie counts, it is unlikely that people eat "normally" while they are recording. It is well-known that those who are conscious of their body fat underreport their food intake. It is also hard to complete and describe "normal" by record. In reporting, athletes try to appear as "good" as possible and thereby cover-up the clues to any energy balance problems. The behavior of individuals may also be masked by the "averaging" of results.
The other study by Flynn et al.(1990) examined energy and fuel usage during training sessions and recovery in swimming and running. It theorized that differences in hormonal patterns and the oxidation of fat might explain differences in body fat levels. Swimmers and runners trained for 45 minutes at 75-80% V02max then recovered for 2 hours. Triathletes did one session of each so that results could be compared for the same individual. During these periods, blood hormone levels, glucose and fatty acid levels, and gas exchange were measured and oxidation of various body fuels monitored.
The results showed no differences in total energy expenditure during training or recovery between groups. There were some differences in substrate utilization and hormone levels. For example, swimming resulted in lower blood glucose levels than running, with some evidence of a greater reliance on carbohydrate as a fuel during swimming. This is likely to be further accentuated in the real life training of swimmers who undertake a high proportion of high-intensity interval work. During recovery, fat oxidation tended to be greater after swimming than running. Overall, these differences were small and could not explain why swimmers have higher body fat levels.
While theories abound, no studies can verify or explain a real difference. These studies clearly leave the way open for further research. Techniques such as the double-labelled water method of energy expenditure estimation might provide a new way to measure energy balance issues. A final idea that needs to be explored is whether a selection process is at hand. Elite swimmers may be predisposed to have higher body fat levels because it is a help, or at least less of a disadvantage, to their swimming. Rounded shoulders and smooth curves may be more biomechanically sound than bony angles. Higher body fat levels are a greater disadvantage to weight-bearing sports like running. So perhaps those who aren't genetically inclined to very low body fat levels, but are otherwise possessive of high-level endurance qualities, should head for the water at an early age!
Flynn, M.L., Costill, D.L., Kirwan, J.P., Mitchell, J.B., Houmard, J.A., Fink, W.J., Beltz, J.D., D'Acquisto, L.J. (1990). Fat storage in athletes: metabolic and hormonal responses to swimming and running. International Journal of Sports Medicine, 11, 433-440.
Jang, K.T., Flynn, M.G., Costill, D.L., Kirwan, J.P., Houmard, J.A., Mitchell, J.B., D'Acquisto, L.J. (1987). Energy balance in competitive swimmers and runners. Journal of Swimming Research, 3, 19-23.
Edited by Mary Ann Wallace · Webmastered by Jason Nugent · Last updated 16 Nov 97
newseditor=AT=sportsci.org · webmaster=AT=sportsci.org · Homepage · Copyright ©1997
En nog een linkje om het af te maken:
[Link niet meer beschikbaar]
Uit onderzoek blijkt dat zwemmen niet helpt om af te vallen. Tenminste, fietsen/ lopen e.d. is beter.
http://www.ncbi.nlm.nih.gov/entrez/...ed&dopt=Abstract&list_uids=3618879&query_hl=1
1: Am J Sports Med. 1987 May-Jun;15(3):275-9.
Related Articles, Links
Weight loss without dietary restriction: efficacy of different forms of aerobic exercise.
Gwinup G.
Since obese patients with orthopaedic disabilities are often advised to undertake swimming as a part of a weight loss program, the effect of swimming on body weight was systematically studied. Minimally to moderately obese, otherwise healthy young women seeking to lose weight through a program of exercise without dietary restrictions were randomly assigned to one of three groups in which only the type of daily exercise was different. The three types of exercise were brisk walking, riding a stationary cycle, and swimming laps in a pool. All women slowly but progressively increased the time spent in daily exercise to 60 minutes. After 6 months or slightly longer, the women assigned to walking lost 10% of initial weight, the women who cycled lost 12%, but the women who swam lost no weight. The thickness of the subcutaneous panniculus over the middle of the extensor surface of the upper arm was measured using a Lang skin-fold caliper (Graham Field Co, New York, NY) and showed equivalent substantial reductions in the walkers and cyclists, but no change in the swimmers. The results of this study show that both walking and cycling are effective methods of reducing body fat, but that swimming is not.
Publication Types:
Clinical Trial
Randomized Controlled Trial
PMID: 3618879 [PubMed - indexed for MEDLINE]
Helaas is er nog geen verklaring hiervoor.
http://www.sportsci.org/jour/sportnutr.html#fat
en op bovenste link klikken
Ondanks gelijke calorie-inname en energieverbruik, hebben zwemmers meer vet dan hardlopers/fietsers.
· Index
SWIMMERS: Body fat mystery!
Louise Burke, Australian Institute of Sport, Canberra, Australia
Swimmers, especially female swimmers, face an energy balance conundrum. Elite swimmers typically undertake 4000-20,000 m per day in training, burning thousands of calories. However, the typical body fat levels of these athletes are significantly higher than runners or cyclists who expend similar or even smaller amounts of energy in their training. Many female swimmers have fought well-publicized battles with their body fat levels and with their coaches! They are generally prescribed "land training" (running or cycling) in addition to their many laps of the pool in the belief that it is a necessary treatment to produce lower skinfold levels.
Do energy discrepancies really exist in swimming? Why do swimmers seem to have drawn the short straw of body fat management? The following theories have been suggested:
Swimmers have higher energy intakes than other athletes and eat more energy than they expend. It has been suggested that swimming doesn't cause the appetite drop that accompanies heavy running and cycling training. Many people observe that they feel like "eating a horse" after they have finished a swim training session, and may overcompensate for the energy they have just burned. Some research suggests that this is due to the cool temperatures in which swimmers train. By contrast, runners and cyclists usually experience an increase in body temperature during training, which may serve to suppress appetite - at least in the short term.
Swimmers are less active outside their training sessions. They are so tired from the hours spent training that they sleep, sit or otherwise avoid any real energy expenditure outside their sessions.
Two studies from Costill's Human Performance Laboratory at Ball State University have tried to address the energy balance oddity of swimmers. Jang et al.(1987) attempted to gain a crude measure of daily energy balance by comparing collegiate swimmers and collegiate distance runners. Ten athletes of each coïtus from each sport participated in the study. The findings: runners had lower body fat levels than swimmers (7% v 12% for male runners v swimmers, and 15% v 20% for females). All subjects kept detailed 3-day food records, and 1-day activity records were kept by half the subjects in each group. These records noted the amount of time each individual spent sleeping, sitting, walking, standing or training. The energy cost of these activities was estimated individually for each athlete by duplicating the activity in the laboratory and collecting oxygen consumption data. This factor multiplied by the time spent in each activity produced an estimate of total daily energy expenditure.
Results showed that both groups reported similar daily energy intakes: 3380 kcal and 3460 kcal for male swimmers and runners; 2490 kcal and 2040 kcal for female swimmers and runners, respectively. Estimated energy output was in agreement for each group, with the values for the groups of male athletes being roughly equal and similar to their reported intake. The female swimmers had a higher energy expenditure than female runners, and in fact were in slight negative energy balance. These results were not helpful in finding or explaining an energy dilemma, or major differences between types of athletes. The theories above might explain the problems experienced by some individual swimmers, but the theories were not supported by evidence from the study.
One of the limitations of this study is that each method of measuring energy balance is subject to considerable flaws. It is almost impossible to measure usual energy intake from diaries. Apart from the errors in translating descriptions of food into calorie counts, it is unlikely that people eat "normally" while they are recording. It is well-known that those who are conscious of their body fat underreport their food intake. It is also hard to complete and describe "normal" by record. In reporting, athletes try to appear as "good" as possible and thereby cover-up the clues to any energy balance problems. The behavior of individuals may also be masked by the "averaging" of results.
The other study by Flynn et al.(1990) examined energy and fuel usage during training sessions and recovery in swimming and running. It theorized that differences in hormonal patterns and the oxidation of fat might explain differences in body fat levels. Swimmers and runners trained for 45 minutes at 75-80% V02max then recovered for 2 hours. Triathletes did one session of each so that results could be compared for the same individual. During these periods, blood hormone levels, glucose and fatty acid levels, and gas exchange were measured and oxidation of various body fuels monitored.
The results showed no differences in total energy expenditure during training or recovery between groups. There were some differences in substrate utilization and hormone levels. For example, swimming resulted in lower blood glucose levels than running, with some evidence of a greater reliance on carbohydrate as a fuel during swimming. This is likely to be further accentuated in the real life training of swimmers who undertake a high proportion of high-intensity interval work. During recovery, fat oxidation tended to be greater after swimming than running. Overall, these differences were small and could not explain why swimmers have higher body fat levels.
While theories abound, no studies can verify or explain a real difference. These studies clearly leave the way open for further research. Techniques such as the double-labelled water method of energy expenditure estimation might provide a new way to measure energy balance issues. A final idea that needs to be explored is whether a selection process is at hand. Elite swimmers may be predisposed to have higher body fat levels because it is a help, or at least less of a disadvantage, to their swimming. Rounded shoulders and smooth curves may be more biomechanically sound than bony angles. Higher body fat levels are a greater disadvantage to weight-bearing sports like running. So perhaps those who aren't genetically inclined to very low body fat levels, but are otherwise possessive of high-level endurance qualities, should head for the water at an early age!
Flynn, M.L., Costill, D.L., Kirwan, J.P., Mitchell, J.B., Houmard, J.A., Fink, W.J., Beltz, J.D., D'Acquisto, L.J. (1990). Fat storage in athletes: metabolic and hormonal responses to swimming and running. International Journal of Sports Medicine, 11, 433-440.
Jang, K.T., Flynn, M.G., Costill, D.L., Kirwan, J.P., Houmard, J.A., Mitchell, J.B., D'Acquisto, L.J. (1987). Energy balance in competitive swimmers and runners. Journal of Swimming Research, 3, 19-23.
Edited by Mary Ann Wallace · Webmastered by Jason Nugent · Last updated 16 Nov 97
newseditor=AT=sportsci.org · webmaster=AT=sportsci.org · Homepage · Copyright ©1997
En nog een linkje om het af te maken:
[Link niet meer beschikbaar]