Swimmers, Watermelon Spitting, and Sleep Apnea

I think what makes a really good aerobic athlete, vis a vis VO2 Max (see Phil Whitten's interesting article in this month's Swimmer) is not so much the quantity of oxygen you can inhale but the quantity you can use. The trained muscles of top distance swimmers are superb at extracting loads of oxygen from the blood stream. That's true -- the lungs, as we say, are "over-engineered" for exercise. In patients with normal lung volumes and airway function, the respiratory system is almost never the cause of limitation of aerobic exercise (VO2 max). The limitation will be in the heart and circulatory system's ability to deliver the oxygen and the muscle's ability to extract energy. There is some evidence that swimmers do have bigger lungs than other athletes: Br J Sports Med 1997; 31: 337-341 I'll quote briefly from the discussion: The results of this study support previous work indicating that lung volume is increased in young male and female swimmers compared with both sedentary subjects' ' and land based athletes.4 7-11 Indeed, our results show that female swimmers have absolute lung volumes similar to male land based athletes and sedentary control groups (tables 2 and 3). While land based athletes and sedentary control groups have "normal" values in relation to age, stature, and sex, both male and female swimmers have FEV,1 values about 11% higher than predicted values. These results are in agreement with previous studies that have measured lung volume in swimmers. 3-8 9-11 18 22 33-35 To whatextent the superior lung volume in swimmers isa consequence of training, and to what extent it may be due to natural endowment is equivocal. In swimming, the load of the water pressure against the chest wall and elevated airway resistance as the result of immersion could comprise a conditioning stimulus as well as the requirement that inspirations must occur rapidly from functional residual capacity during short intervals between strokes.'8 On the other hand, there is also support in the literature for a substantial contribution from genetic endowment to the enhanced lung function in swimmers. Baxter-Jones and Helms9 studied a sample of 231 highly trained male swimmers, gymnasts, and soccer and tennis players. Of the four sports, the swimmers had the highest initial lung volume in each of five age cohorts (8, 10, 12, 14, 16 years). Having controlled for factors such as age, stature, body mass, and training hours, multilevel regression analysis showed that the difference in lung size between the sports did not change with time. Ericksson et af3 have also noted that increased lung volume was already present in a group of 10 year old boys (n = 18) who had just begun swimming training. Furthermore, other studies were unable to detect lung volume increases in child swimmers after six or seven months of training.34 3 Because of the cross sectional nature of the present study, the results cannot exclude genetic endowment as a major determinant of the superior lung volume observed in elite swimmers. Zinman and Gaultier22 have suggested that to differentiate natural endowment from adaptive growth, it is necessary to examine the mechanical characteristics of the respiratory system of swimmers in more detail. Their work brings attention to the disproportionate development of air spaces in normal children, and this development has been noted to be even more pronounced as a result of adaptive growth in high altitude dwellers.36 Cotes37 points out that the increased lung volume observed in residents of high altitude may be the direct consequence of a combination of hypoxaemia and a high level of habitual physical activity during childhood rather than the stress of hypoxaemia alone. Documentation of a greater disproportionate development of air spaces in swimmers compared with controls would support the hypothesis that swimmers have larger lung volume as the result of adaptive growth rather than genetic endowment.22 I doubt that training makes a big impact on lung volume -- and probably not in adults but some people apparently disagree with that somewhat. When it comes to spitting watermelon seeds, I would bet that there are all kinds of technique issues that are more important than lung function. Probably you can send a video of yourself spitting seeds to some guy and he'll give you some pointers. Jim, it sounds like your respironics was set up in the timed mode when it should have been in "spontaneous" -- anyways glad you've got a set up that's working now.

I think what makes a really good aerobic athlete, vis a vis VO2 Max (see Phil Whitten's interesting article in this month's Swimmer) is not so much the quantity of oxygen you can inhale but the quantity you can use. The trained muscles of top distance swimmers are superb at extracting loads of oxygen from the blood stream. That's true -- the lungs, as we say, are "over-engineered" for exercise. In patients with normal lung volumes and airway function, the respiratory system is almost never the cause of limitation of aerobic exercise (VO2 max). The limitation will be in the heart and circulatory system's ability to deliver the oxygen and the muscle's ability to extract energy. There is some evidence that swimmers do have bigger lungs than other athletes: Br J Sports Med 1997; 31: 337-341 I'll quote briefly from the discussion: The results of this study support previous work indicating that lung volume is increased in young male and female swimmers compared with both sedentary subjects' ' and land based athletes.4 7-11 Indeed, our results show that female swimmers have absolute lung volumes similar to male land based athletes and sedentary control groups (tables 2 and 3). While land based athletes and sedentary control groups have "normal" values in relation to age, stature, and sex, both male and female swimmers have FEV,1 values about 11% higher than predicted values. These results are in agreement with previous studies that have measured lung volume in swimmers. 3-8 9-11 18 22 33-35 To whatextent the superior lung volume in swimmers isa consequence of training, and to what extent it may be due to natural endowment is equivocal. In swimming, the load of the water pressure against the chest wall and elevated airway resistance as the result of immersion could comprise a conditioning stimulus as well as the requirement that inspirations must occur rapidly from functional residual capacity during short intervals between strokes.'8 On the other hand, there is also support in the literature for a substantial contribution from genetic endowment to the enhanced lung function in swimmers. Baxter-Jones and Helms9 studied a sample of 231 highly trained male swimmers, gymnasts, and soccer and tennis players. Of the four sports, the swimmers had the highest initial lung volume in each of five age cohorts (8, 10, 12, 14, 16 years). Having controlled for factors such as age, stature, body mass, and training hours, multilevel regression analysis showed that the difference in lung size between the sports did not change with time. Ericksson et af3 have also noted that increased lung volume was already present in a group of 10 year old boys (n = 18) who had just begun swimming training. Furthermore, other studies were unable to detect lung volume increases in child swimmers after six or seven months of training.34 3 Because of the cross sectional nature of the present study, the results cannot exclude genetic endowment as a major determinant of the superior lung volume observed in elite swimmers. Zinman and Gaultier22 have suggested that to differentiate natural endowment from adaptive growth, it is necessary to examine the mechanical characteristics of the respiratory system of swimmers in more detail. Their work brings attention to the disproportionate development of air spaces in normal children, and this development has been noted to be even more pronounced as a result of adaptive growth in high altitude dwellers.36 Cotes37 points out that the increased lung volume observed in residents of high altitude may be the direct consequence of a combination of hypoxaemia and a high level of habitual physical activity during childhood rather than the stress of hypoxaemia alone. Documentation of a greater disproportionate development of air spaces in swimmers compared with controls would support the hypothesis that swimmers have larger lung volume as the result of adaptive growth rather than genetic endowment.22 I doubt that training makes a big impact on lung volume -- and probably not in adults but some people apparently disagree with that somewhat. When it comes to spitting watermelon seeds, I would bet that there are all kinds of technique issues that are more important than lung function. Probably you can send a video of yourself spitting seeds to some guy and he'll give you some pointers. Jim, it sounds like your respironics was set up in the timed mode when it should have been in "spontaneous" -- anyways glad you've got a set up that's working now.