Physiological characteristics of young well-trained swimmers

Effect of the Reduction in Training Volume during the COVID-19 Era on Performance in 100-m and 400-m Freestyle Events in Greek Swimming Championships

The COVID-19 pandemic had a profound impact on almost all social activities, including sport participation. Swimming training was greatly reduced during the 2019−2020 and 2020−2021 seasons (by four and two months, respectively), which caused athletes and coaches to worry about performance in championships. The present study investigated the impact of COVID-19 lockdowns on the results of Greek swimming championships in the categories of 13 to 18 years of age during 2020 and 2021. Forty-one coaches were interviewed about the training process (satisfaction, duration of the training season, and daily training swimming distance), and the performance of swimmers in national championships over seven seasons (2014−2021) was analyzed. The duration of the training season and the daily swimming distance, as reported by the coaches, were lower during the 2019−2020 and 2020−2021 seasons, compared to the previous five seasons (p < 0.001). The number of swimmers who achieved qualifying times for the national championships during the COVID-19 era were similar to those in previous years. Comparisons of the times in the 100-m and 400-m freestyle events, in both genders, from 2015 through 2021, showed no significant differences except for the 400-m event in males, in which a lower performance was detected in 2021 compared to 2015 (by 2.7%, p = 0.001). In conclusion, two or four months of detraining during the COVID-19 era had a negative impact on the coaches’ evaluation of the training process, but there was no effect on the number of young swimmers who qualified for the national championships and a negligible effect on swimming performance in 100-m and 400-m freestyle events.

Determinants of lung function changes in athletic swimmers. A review

AIM

To summarise lung function characteristics of athletic swimmers and discuss mechanisms explaining these changes while putting forward the lack of a clear understanding of the precise physiological factors implicated.

METHODS

Literature search until 07.2021 on Medline and EMBASE using keywords swimming, athletes, respiratory physiology, lung development, lung function tests. Relevant articles in French and English were reviewed.

RESULTS

We found insufficient data to perform a meta-analysis. However, there is evidence that swimmers have better expiratory flows and increased baseline lung volumes than non-athletes or non-swimmers. Although these features can result from changes in lung development following intense training over the years, the contribution of a genetic predisposition and positive selection cannot be totally excluded.

CONCLUSION

Disentangling the participation of constitutional factors and years of hard training to explain the larger lung volumes of athletic swimmers is in favour of an adaptative response of the lungs to early swim training through modification of the pathway of lung development. There seems to be an optimal window of opportunity before the end of growth for these adaptational changes to occur. Precise mechanisms, and contribution of adaptative change on lung physiology, remain to be further studied.

Analysis of high predicted pulmonary function: possibility of overestimation in small elderly examinees

BACKGROUND/AIMS

Few studies have attempted to interpret unusually high predicted pulmonary function test results. This study aimed to investigate the demographic features of patients with an unusually high predicted pulmonary function.

METHODS

The demographic data of subjects who underwent pulmonary function testing at a tertiary referral hospital during between January 2011 and December 2011 were retrospectively reviewed.

RESULTS

Of the 68,693 included patients, 55 (0.08%) had a percent predicted forced expiratory volume in 1 second or forced vital capacity ≥ 140%. These patients had a relatively older median age (72 years vs. 54 years, p < 0.001), female predominance (65.5% vs. 42.5%, p = 0.001), lower body weight (52.5 kg vs. 64.5 kg, p < 0.001) and shorter height (148.4 cm vs. 164.2 cm, p < 0.001). Furthermore, 6.1% of women older than 80 years with weight < 50 kg and height < 150 cm had a high predicted pulmonary function.

CONCLUSION

A high predicted pulmonary function is not rare among elderly subjects with a small body size. Physicians should consider the demographics of the examinees, especially those of minority populations, particularly as the test results might be determined using an incorrect reference equation.

A comparison of shoulder muscular performance and lean mass between elite and recreational swimmers: Implications for talent identification and development

This study compared the shoulder muscular performance and lean mass between elite and recreational swimmers.Thirty elite swimmers (mean age ± standard deviation = 23.1 ± 3.5 years) and 21 recreational swimmers (mean age ± standard deviation = 20.8 ± 2.1 years) participated in the study. Maximum muscle strength and time to maximum muscle strength of shoulder flexor, extensor, abductor, and adductor muscles were measured using a handheld dynamometer. Lean mass of the arms and body (excluding the head) were measured using dual-energy x-ray absorptiometry (DXA).Results revealed that compared with recreational swimmers, elite swimmers had higher maximum muscle strength of the shoulder flexor, extensor, abductor, and adductor muscles (all P < .001). The time to reach maximum muscle strength of all shoulder muscles showed no significant difference between the 2 groups (P > .05). The lean mass values in the left arm (P = .037), right arm (P < .001), and whole body (P = .014) were higher in elite swimmers than recreational swimmers.Elite swimmers had greater shoulder maximum muscle strength compared with recreational swimmers though the time taken to reach maximum muscle strength was similar between the 2 groups. Elite swimmers also showed a higher lean mass in both arms and their entire body when compared with recreational swimmers. The results may be useful for recreational swimmers who intend to advance to professional level, and for talent identification and early development of elite swimmers.

Diffusion capacity of carbon monoxide (DLCO) pre- and post-exercise in children in health and disease

RATIONALE

A decrease in diffusion capacity for carbon monoxide (DLCO) after exercise has been reported in healthy adults. There is limited information for post-exercise DLCO available in children either in health or in disease.

OBJECTIVES

To evaluate (1) reproducibility of DLCO measures in children, (2) differences in DLCO between elite athletic swimmers (AS), stable cystic fibrosis patients (CF), and healthy controls (Con) at rest; and (3) after a maximal treadmill exercise test.

METHODS

Participants performed spirometry and DLCO at baseline, a maximal treadmill exercise test and repeated DLCO measures for 2 hr after cessation of exercise.

RESULTS

The mean (SD) co-efficient of variation between baseline DLCO tests was 2.49% (1.86%). In girls, the mean baseline DLCO (ml/min/mmHg) was 18.61 (4.15) in CF, 22.32 (4.79) in controls and 27.18 (5.33) in AS. In boys: 23.68 (5.31) in CF, 28.09 (9.95) in controls and 37.75 (9.46) in AS. Baseline DLCO was significantly higher in AS than in CF patients (P < 0.01). In girls post-exercise, the greatest mean decrease in DLCO from baseline was -7.50% to -12.83% and in boys -6.92% to -17.71%. The decline in DLCO was less important in the athletes than the other groups (P < 0.05).

CONCLUSIONS

DLCO is highly repeatable in children. AS have an increased DLCO at rest compared to both children with CF and controls. There is a decline from baseline to post-exercise DLCO and while there are disease-specific differences, the general pattern of change in DLCO measures after exercise is similar in children to adults.

Diffusion capacity in children: what happens with exercise?

There is comparatively little data on diffusion capacity in children during exercise. With the advent of improved technology, there is an increasing interest in exercise testing of children in order to predict the evolution of lung disease. In addition to the standard measure of exercise capacity, the VO(2max), interest is evolving in the consequences of alterations in diffusion capacity which may be unmasked with exercise. This review will consider what is known about diffusion capacity with exercise in children with well documented lung disease in the form of cystic fibrosis, healthy controls and swimmers as elite athletes with the largest lung volumes.

Maximal oxygen uptake in well-trained and untrained 9-11 year-old children

There is a world-wide trend for children to begin serious athletic training at progressively younger ages. Since there are no data concerning the cardiorespiratory function of Turkish children, the purpose of this study was to compare maximal oxygen uptake in well-trained and untrained children of similar ages. The trained subjects (20) were junior swimmers from a private college swimming team, and the untrained ones (20) were from the same school. Maximal oxygen uptake was directly measured during progressive treadmill exercise using open circuit spirometry. No significant differences in height, mass, and age were noted between the trained and untrained groups. Maximal aerobic power in absolute values and expressed per kilogram of body mass, was 19.57% and 20.06%, respectively: higher in the trained than in the untrained group (p < 0.05). These data suggest that physical training significantly increases maximal aerobic power in young subjects.

Pre-season physiological characteristics of English first and second division soccer players

This investigation was undertaken in an effort to establish physiological characteristics of soccer players and to relate them to positional roles. A total of 135 footballers (age 24.4 +/- 4.6 years) were assessed for body mass, % body fat, haemoglobin, maximal oxygen uptake (VO2 max), leg power, anaerobic capacity and speed prior to an English league season. The sample included 13 goalkeepers, 22 full-backs, 24 centre-backs, 35 midfield players and 41 forwards. The goalkeepers were significantly heavier (86.1 +/- 5.5 kg; P < 0.01) than all groups except the centre-backs, had significantly higher estimated body fat percentages than centre-backs, forwards, midfield players (P < 0.01) or full-backs (P < 0.05), significantly lower estimated VO2 max values (56.4 +/- 3.9 ml kg-1 min-1; P < 0.01) and were slowest over 60 m (12.71 +/- 0.42 s). The midfield players had the highest predicted VO2 max values (61.4 +/- 3.4 ml kg-1 min-1), this being significantly greater (P < 0.05) than for the centre-backs. The forwards were the fastest group over 60 m (12.19 +/- 0.30 s), being significantly quicker than goalkeepers or centre-backs (P < 0.01) and full-backs (P < 0.05). Anaerobic power, as well as knee extensor torques (corrected for body mass) and extensor-flexor ratios, were similar between groups. No difference in estimated body fat percentage was observed between any of the outfield players, and haemoglobin concentrations were similar among players of all positions.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary intakes of age-group swimmers

The purposes of this study were to collect information regarding the dietary habits of male and female age-group swimmers and report the energy consumptions of these athletes in relation to their daily training demands. Twenty competitive swimmers, who were training 6000 m per day 6 days a week, recorded all fluid and food consumed during a 4-day period. Dietary analysis revealed that 11 swimmers (55%) had calcium intakes below recommended dietary allowances (RDA), while 13 (65%) had iron intakes lower than RDA. Despite identical training loads and body mass, male swimmers had significantly greater (P = 0.004) daily mean (s.d.) energy consumption (3072(732) kcal, 12.9(3.1) MJ) than females (2130(544) kcal, 8.9(2.3) MJ) and were maintaining energy balance. Although the contribution of carbohydrate to total daily energy intake was the same for male (55%) and female swimmers (56%), the females ingested significantly less (P = 0.011) carbohydrate (292(87) g) than the males (404(88) g) and could be considered deficient in dietary carbohydrate with respect to their daily training demands.

Applied physiology of swimming

Scientific research in swimming over the past 10 to 15 years has been oriented toward multiple aspects that relate to applied and basic physiology, metabolism, biochemistry, and endocrinology. This review considers recent findings on: 1) specific physical characteristics of swimmers; 2) the energetics of swimming; 3) the evaluation of aerobic fitness in swimming; and 4) some metabolic and hormonal aspects related to swimmers. Firstly, the age of finalists in Olympic swimming is not much different from that of the participants from other sports. They are taller and heavier than a reference population of the same age. The height bias in swimming may be the reason for lack of success from some Asian and African countries. Experimental data point toward greater leanness, particularly in female swimmers, than was seen 10 years ago. Overall, female swimmers present a range of 14 to 19% body fat whereas males are much lower (5 to 10%). Secondly, the relationship between O2 uptake and crawl swimming velocity (at training and competitive speeds) is thought to be linear. The energy cost varies between strokes with a dichotomy between the 2 symmetrical and the 2 asymmetrical strokes. Energy expenditure in swimming is represented by the sum of the cost of translational motion (drag) and maintenance of horizontal motion (gravity). The cost of the latter decreases as speed increases. Examination of the question of size-associated effects on the cost of swimming using Huxley's allometric equation (Y = axb) shows an almost direct relationship with passive drag. Expressing energy cost in litres of O2/m/kg is proposed as a better index of technical swimming ability than the traditional expression of VO2/distance in L/km. Thirdly, maximal direct conventional techniques used to evaluate maximal oxygen consumption (VO2 max) in swimming include free swimming, tethered swimming, and flume swimming. Despite the individual peculiarities of each method, with similar experimental conditions similar results for VO2 max will be found. Free swimming (unimpeded) using the backward extrapolation method will, however, lead to reliable and valid results obtained in a condition that is closer to the competitive situation than with a direct test. A maximal indirect field-test has been recently made available. This test can predict VO2 max with an acceptable accuracy (r = 0.877), and provides a mean to evaluate the functional maximal aerobic power in swimming which corresponds to the maximal aerobic swimming velocity.(ABSTRACT TRUNCATED AT 400 WORDS)

Biological characteristics of young swimmers, tennis players and non-competitors

One hundred and twelve finalists in the State Swimming Championships aged between seven and twelve years and 65 ranked tennis players of similar age were selected on the basis of their sporting performances. A third group comprised children of similar socio-economic status who only took part in casual sport. The tests which were used in the study were those considered to be important for successful athletic performance. A multifactorial analysis of variance and post-hoc t-tests were applied to the data to determine if any statistical differences were apparent between the three groups. The results demonstrated that no size, body shape, flexibility, strength or lung function differences were evident between the competitors and non-competitors, but that the swimmers and tennis players were superior to the non-competitors in cardiovascular endurance.

Physical work capacity and lung function in competitive swimmers

Competitive swimmers require a high aerobic capacity to support the sustained performance of severe exercise. Maximal oxygen uptake values and blood lactate concentrations were measured in ten male and fifteen female swimmers from the Scottish National and Youth Squads 1981-82. Lung function tests were also performed to determine pulmonary efficiency. The results of these studies were compared with other investigations of international competitive swimmers and indicate a high level of fitness among Scottish national swimmers.

Anthropometric, body composition, and maturity characteristics of selected school-age athletes

Young athletes of both sexes grow as well as nonathletes. The experience of athletic training and competition does not harm the physical growth and development of the youngster. The young, trained athlete has generally a lesser percentage of body weight as fat. Maturity relationships are not consistent across sports. Male athletes more often than not tend to be advanced maturationally compared with nonathletes. On the other hand, female athletes tend to be delayed in maturity, except for swimmers. Maturity-associated variation in size and body composition is thus a significant factor in comparing athletes and nonathletes, especially during the circumpuberal years.