KINEMATIC VARIABLES AND BLOOD ACID-BASE STATUS IN THE ANALYSIS OF COLLEGIATE SWIMMERS’ ANAEROBIC CAPACITY

Short duration repeated maximal efforts are often used in swimming training to improve lactate tolerance, which gives swimmers the ability to maintain a high work rate for a longer period of time. The aim of the study was to examine the kinematics of swimming and its relation to the changes in blood acid-base status and potassium level. Seven collegiate swimmers, with at least 6 years of training experience, volunteered to participate in the study. The test consisted of 8 x 25 m front crawl performed with maximum effort. The rest period between repetitions was set to five seconds. Blood samples were taken from the fingertip at rest, after warm-up and in the 3rd minute after completion of the test. The swimming was recorded with a video recorder, for later analysis of time, velocity and technique (stroke index). Based on the swimming velocity results, the obtained curve can be divided into rapid decrease of velocity and relatively stable velocities. The breaking point of repetition in swimming velocity was assumed as the swimming velocity threshold and it was highly correlated with the decrease of the blood acid-base status (pH r=0.82, BE r=0.87, HCO₃ ^- r=0.76; p<0.05 in all cases). There was no correlation between stroke index or fatigue index and blood acid-base status. Analysis of the swimming speed in the 8 x 25 m test seems to be helpful in evaluation of lactate tolerance (anaerobic capacity) in collegiate swimmers.     

桂林市游泳儿童隐孢子虫感染现状调查

目的 了解广西壮族自治区桂林市游泳儿童隐孢子虫感染现状。方法 根据桂林市地理位置抽取6家游泳馆,于2017年8月初问卷调查选中游泳馆中小于14岁的游泳儿童,同时采集儿童24 h内的新鲜粪便,使用RIDA®隐孢子虫快速检测法检测粪便隐孢子虫卵囊;每个游泳馆采集2次泳池水样,每次采集1份水样,并于4 h内检测水质微生物指标（细菌总数、大肠菌群）,其余水质指标（游离性余氯、浑浊度、尿素、pH）现场测定。结果 共调查298人（2～13岁）,男性儿童165人,女性儿童133人,游泳儿童隐孢子虫感染率为4.0%,其中男性儿童感染率为4.2%,女性儿童感染率为3.8%,5岁以下游泳儿童感染率最高（4.5%）,10岁以上游泳儿童感染率最低（2.9%）;6家游泳馆水质检测指标中尿素（33.3%）和余氯（16.7%）合格率较低,其余检测指标（浑浊度、pH、细菌总数、大肠菌群）合格率为100.0%。游泳儿童隐孢子虫感染人数在不同性别、年龄段中差异无统计学意义（P>0.05）;在不同余氯浓度、不同浑浊度游泳馆中分布差异有统计学意义（P<0.05）,。结论 该地区游泳儿童存在隐孢子虫感染;增加泳池余氯量不能降低游泳儿童感染隐孢子虫的风险,降低泳池水浑浊度有利于降低游泳儿童隐孢子虫感染风险。     

Socio-economic factors in relation to lipid profiles in young girl athletes

The influence of socio-economic factors on blood lipid values was studied in 4 groups of young female athletes. Based on type of sport (gymnastics and swimming) and of training intensity, the participants were subdivided into 25 talented, high achievement gymnasts (age 12.3 +/- 1.6 (SD) year), 42 non-talented, low achievement gymnasts (age 12.0 +/- 1.2 (SD) year), 12 high achievement swimmers (age 10.3 +/- 1.6 (SD) year), and 24 low achievement swimmers (age 10.8 +/- 1.6 (SD) year). With respect to socio-economic factors, no significant differences were observed between the two gymnastic groups nor between the two swimming groups. The blood lipid values revealed a significantly higher low density lipoprotein-cholesterol level and significantly lower high density lipoprotein-cholesterol/total cholesterol and high density lipoprotein-cholesterol/low density lipoprotein cholesterol ratios in the talented gymnasts as compared to the non-talented gymnasts. In the high achievement swimmers, low density lipoprotein-cholesterol and triglyceride levels were significantly lower and high density lipoprotein-cholesterol/total cholesterol was significantly higher as compared to the other swimmers. The Spearman rank order correlation coefficients for the relationships between socio-economic factors and blood lipid values were mostly weak or inconsistent. Therefore, no major influence of socio-economic factors on blood lipid values could be demonstrated in the groups investigated.     

Changes in serum proteins,-iron and -copper in swimmers before and after altitude training (author's transl)]

Fifteen male swimmers (mean age 19.3 +/- 2.1 years) were subjected to a standard 120 min swimming exercise test: a) before, and b) after 5 weeks of intensive training at middle altitude (2000 m). At rest, serum levels of alpha2-macroglobulin, transferrin and copper were elevated in swimmers as compared to untrained subjects. After the altitude training program, significant increases of the parameters of iron and copper metabolism, as well as of alpha2HS-glycoprotein and beta1A-globulin were observed. After the first exercise test (a), a significant rise in serum alpha1-acid glycoprotein, alpha1-antitrypsin, hemopexin, alpha2-macroglobulin, ceruloplasmin, transferrin, iron, copper and alpha2-HS-glycoprotein was noted. The same 120 min-exercise test after the altitude training (b) led to only small changes, especially as concerns the parameters of iron metabolism. The characteristic immediate and long-lasting changes in serum proteins and heavy metals in swimmers and the effects of training in middle altitude on the answer of the organism to swimming exercise with respect to the mentioned biochemical parameters are discussed.     

BDKRB2 GENE -9/+9 POLYMORPHISM AND SWIMMING PERFORMANCE

The aim of the study was to evaluate the association between swimming performance and the -9/+9 (rs5810761) polymorphism within the BDKRB2 gene in successful competitive swimmers. Best individual swimming results expressed in FINA points achieved at short, middle and long distance events of 157 well-trained Polish swimmers were incorporated into an analysis. Athletes’ genotype and allele distributions were analysed in comparison to 230 unrelated sedentary subjects who served as controls with the χ² test. All samples were genotyped for the BDKRB2 -9/+9 polymorphism using the polymerase chain reaction (PCR). The effects of genotype on swimming performance were analysed with two-way (3 x 2; genotype x gender) analysis of variance with metrical age as a covariate for each distance specialization. No statistical differences in the genotype and allele frequencies were found in long distance swimmers when compared with the total group of swimmers or controls. The BDKRB2 +9/-9 genotype had no significant effect on swimming performance at short, middle or long distance, regardless of gender. The results of this study do not support the hypothesis that the BDKRB2 -9/+9 polymorphism is associated with swimming performance in Polish swimmers.     

Effect of intensive swimming training on lung volumes, airway resistances and on the maximal expiratory flow-volume relationship in prepubertal girls

The aim of the present study was to analyse the effect of 1 year of intensive swimming training on lung volumes, airway resistance and on the flow-volume relationship in prepubertal girls. Five girls [9.3 (0.5) years old] performing vigorous swimming training for 12 h a week were compared with a control group of 11 girls [9.3 (0.5) years old] who participated in various sport activities for 2 h per week. Static lung volumes, maximal expiratory flows (MEF) at 75, 50 and 25% of vital capacity, 1-s forced expiratory volume (FEV_1.0) and airway resistance (R _aw) were measured by means of conventional body plethysmograph techniques. Prior to the training period there were no significant differences between the two groups for any of the parameters studied. Moreover, for both groups, all parameters were within the normal range for children of the corresponding age. After 1 year of training, vital capacity (VC), total lung capacity (TLC) and functional residual capacity (FRC) were larger (P<0.05) in the girl swimmers than in the control group, while physical development in terms of height and weight was similar. FEV_1.0 (P<0.01), MEF₂₅, MEF₅₀ (P<0.05) and MEF₇₅ as well as the ratio MEF₅₀ / TLC (P<0.05) had increased in the girl swimmers but were unchanged in the control group. R _aw tended to be lower in the girl swimmers and higher in the control group. The results indicate that intensive swimming training prepuberty enhances static and dynamic lung volumes and improves the conductive properties of both the large and the small airways. As to the causative mechanism, it can be speculated that at prepuberty intensive swimming training promotes isotropic lung growth by harmonizing the development of the airways and of alveolar lung spaces. Accepted: 5 March 1997     

Effect of various types of sports on the pulmonary rheogram of young school age children

The pulmonary blood circulation of boys aged from 8 to 12 going in for swimming and wrestling has been studied by the rheographic method. It is found that the pulmonary rheogram of young sportsmen differs significantly from the one of non-sportsmen of the same age. The basic wave amplitude is larger, its elevation and fall angle is smaller, presystolic, systolic and diastolic parts are longer, rheographic systolic and diastolic indices as well as vascular wall elasticity index are higher, peripheral resistance of arterioles and cappilaries are lower in trained children. These values demonstrate a decrease in the pulmonary blood flow rate and an increase in its volume as well as improvement of the elastic-viscid properties of blood vessel walls. They also indicate the economy development of pulmonary circulation activity. The mentioned deviations are better expressed in young swimmers.     

Effect of training on hormonal responses to exercise in competitive swimmers.

The effects of 9 weeks of training on responses of plasma hormones to swimming were studied in eight competitive swimmers who had not trained for several months. Two types of swimming tests were used: (1) 200 yd, a high intensity, exhausting type of exercise in which maximal effort was required both before and after training, and (2) 1000 yd, a pace type of exercise in which subjects swam as fast as possible prior to training and at the same rate after training. Plasma levels of glucagon increased and of insulin decreased during 1000 yd of swimming, but were not altered by 200 yd of swimming. No training effects were apparent in responses of plasma insulin and glucagon to these shortterm, high intensity exercise tests. During the 1000 yd swim, plasma adrenaline was 0.8 ng/ml before vs. 0.1 ng/ml after training. Plasma noradrenaline response decreased from 3.4 to 1.2 ng/ml as a result of training. In the 200 yd swim, adrenaline, but not noradrenaline, was lower after training.     

Characteristics of elite open-water swimmers

Open-water swimming (5, 10, and 25 km) has many unique challenges that separate it from other endurance sports, like marathon running and cycling. The characteristics of a successful open-water swimmer are unclear. The purpose of this study was to determine the physical and metabolic characteristics of a group of elite-level open-water swimmers. The open-water swimmers were participating in a 1-week training camp. Anthropometric, metabolic, and blood chemistry assessments were performed on the athletes. The swimmers had a VO(2)peak of 5.51 +/- 0.96 and 5.06 +/- 0.57 ml.kg(-1).min(-1) for males and females, respectively. Their lactate threshold (LT) occurred at a pace equal to 88.75% of peak pace for males and 93.75% for females. These elite open-water swimmers were smaller and lighter than competitive pool swimmers. They possess aerobic metabolic alterations that resulted in enhanced performance in distance swimming. Trainers and coaches should develop dry-land programs that will improve the athlete's muscular endurance. Furthermore, programs should be designed to increase the LT velocity as a percentage of peak swimming velocity.     

Blood lactate and stroke parameters during front crawl in elite swimmers with disability

The purpose of this investigation was to compare the blood lactate concentration ([La]), stroke distance (D(s)), and swim index (SI) during an incremental swim test (IST) in elite swimmers who had a loss in mobility (LM) (n = 6) or who had full mobility (FM) (n = 5) of the lower limbs. The IST consisted of 5 repeats of either 100 or 200 m front crawl depending upon the ability level of the swimmer. The [La] and heart rate measured during the IST showed no significant differences (p > 0.05). However, velocity (V(s)) and D(s) were all significantly lower (p < 0.01) during the IST. SI was significantly (p < 0.01) lower during repeats 1 to 3 and 5, but not repeat 4. These data indicate that the [La] response to incremental exercise is similar during incremental front crawl activity in swimmers suffering from loss of lower limb mobility. However, a critical V(s) is reached in LM swimmers where swimming efficiency is optimal compared with FM swimmers.     

Classification methods can identify external constrains in swimming

The purpose of the present study is to examine whether the use of fins is identifiable based on swimmers’ technique and to find out technique-related features that depict fins’ influence. First, a number of features were extracted from kinematic data given by movement sensors attached to swimmers’ bodies during butterfly swimming technique. Then, dimensionality reduction, feature selection and classification methods were applied to the extracted features. Two classification tasks were defined, one for the three classes of long, short and no fins, attaining accuracy up to 70, 62 and 70%, respectively, and the two-class simplified version (long fins, no fins) with accuracy up to 78%. These high accuracy levels were also found statistically significant and suggest that the use of fins influences swimming technique in a recognizable way and that the selected features that depict those differences are swimming type depended.     

Features of the structure of the metacarpal bones of athletes in different specialties

Metacarpal bones have been examined in hand X-ray photos of 125 sportsmen at the age of 17-18 years who go in for swimming (dynamic loading on the hand) and competitive gymnastics (static loading on the hand). Under the effect of systematic trainings, which are connected with an increased loading on the hand, a number of morphological changes take place in the metacarpal bones. A prolonged loading of the dynamic character delays the synostosis process in the distal parts of the forearm bones and contributes to lengthening the I, III and IV and to widening the I-V metacarpal bones. As demonstrate decreasing indices of compactness in the swimmers, the widening diaphisis of the metacarpal bones occurs at the expense of dilatation of the medullary cavity. The static loadings result in a greater delay of the synostosis processes in the upper extremity parts mentioned, in a greater width of the I-III, V metacarpal bones in boy-gymnasts. The increased index of compactness demonstrates that the widening diaphysis of the metacarpal bones takes place at the expense of thickening of the compact substance and narrowing of the medullary cavity.     

Developmental evaluation of children born to mothers occupationally exposed to waste anesthetic gases

BACKGROUND: The etiology of developmental delay in children is frequently unknown. Increasing evidence supports the possibility that environmental and occupational factors might be part of the basis for such delays. This study focuses on the development of children born to mothers who were exposed during their pregnancy to waste anesthetic gases. METHODS: The study population included 40 children aged 5-13 years born to female anesthesiologists and nurses working in operating rooms (OpRs) exposed to waste anesthetic gases, and 40 unexposed children born to female nurses and physicians who worked in hospitals during their pregnancy but did not work in OpRs. The unexposed group was matched for children's age and gender and maternal occupation (nurses vs. doctors). By means of standardized developmental tests, the present study population was evaluated for their medical and neurodevelopmental state. Questionnaires were given for the detection of attention and activity levels as perceived by the parents. Additional questionnaires dealt with information concerning developmental milestones, maternal and fetal morbidity, and gynecological history. RESULTS: No differences were noted between the groups as newborns or in developmental milestones at the age of 5-13 years; however, the mean score of gross motor ability was significantly lower in the exposed versus the unexposed group. Additionally, the mean score of the DSM-III-R Parent-Teacher Questionnaire (PTQ) (i.e., measure of inattention/hyperactivity) was higher in the exposed group. The level of exposure, as measured by the number of weekly hours in the OpRs, was significantly and negatively correlated with fine motor ability and the score of IQ performance. CONCLUSIONS: Our study supports the hypothesis that occupational exposure to anesthetic gases might be a risk factor for minor neurological deficits of children born to mothers who work in OpRs and therefore indicates the need for more studies in this area and perhaps more caution among OpR pregnant women and employers.     

Standards of morphological development in fetuses and newborns as a method of defining fetal age

Whenever the calendar age of the studied fetal material is not known we are bound to reconstruct it by replacing it with the developmental age. In this paper some common developmental standards used in the determination of fetal age are reviewed. The standards, as found in the relevant literature, are tested against a control group for their accuracy in predicting fetal age. The results indicate considerable discrepancy among the various standards. Further, the developmental ages defined by these standards often differ considerably from the known menstrual age. My own attempt to present a more reliable set of developmental standards is based on the analysis of three morphological features commonly used in biological assessment. Body weight, crown-heel length, and crown-rump length are measured in weekly termed groups representing the 20th-42nd weeks of intrauterine life. The accuracy of body weight and crown-heel length in predicting fetal age is tested both within and against a control group. Statistical analysis show no significant differences between the predicted and known fetal ages. These results indicate that body weight and crown-heel length are reliable developmental standards from which fetal age can be defined.     

Liver-derived endocrine IGF-I is not critical for activation of skeletal muscle protein synthesis following oral feeding

Background

Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon. Atlantic salmon were first classified as either poor or good according to their swimming performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously). Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis) and gene expression analyses of the host response in selected organs.

Results

An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish.

Conclusions

This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish.     

Energy cost of front-crawl swimming in women

The purpose of this study was to examine the relationship between the energy cost of swimming per unit distance (Cs) at different velocities (v) and performance level, body size and swimming technique in women. A total of 58 females swimmers were studied. Three performance levels (A, B, C) were determined, ranging from the slower (A) to the faster (B, C). At level C and at 1.1 m.s-1, Cs,1.1 was reduced by 7% when directly compared to level B. The Cs,1.1 was reduced by 10% when calculated per unit of height (h) and by 37% when calculated per unit of h and hydrostatic lift (HL). For the whole group of swimmers, the equation regression was Cs,1.1 = 0.27 h-2.38 HL - 7.5 (r = 0.53, P less than 0.01). To evaluate the specific influence of arm length two groups of long- and short-armed swimmers were selected among swimmers of similar h and performance. The Cs was significantly higher (P less than 0.05) by 12%, SD 2.2%, for short-armed than for long-armed swimmers. To evaluate the influence of different types of swimming technique, two other groups of similar performance and anthropometric characteristics were selected. The Cs was significantly higher (P less than 0.05) by 12%, SD 4.5% for swimmers using for preference their legs rather than their arms. The Cs of the sprinters was 15.7%, SD 2% higher than that of the long-distance swimmers. For all groups, Cs increased with v on average by 8% to 11% every 0.1 m.s-1. These findings showed that Cs variations of these women were close to those previously demonstrated for men. The Cs depends on performance level, body size, buoyancy, swimming technique and v.     

The effects of swimming and running regimens on skeletal muscle glycogen in the rat.

Endurance capacity and the effects of different post-exercise states on skeletal muscle glycogen have been studied in rats trained by swimming or running and in sedentary controls. Regular endurance exercise resulted in increased skeletal muscle glycogen stores. A greater depletion was observed in trained animals than in non-trained animals after a training bout or exhaustive exercise. While muscle glycogen levels did not reflect a differential training stimulus (running vs swimming), swimming as a measure of exhaustive exercise was deemed invalid because of the ability of trained swimmers to avoid stenuous exercise by an alteration of swimming pattern.     

Dry-land strength training vs. electrical stimulation in sprint swimming performance

This study was undertaken to compare the effects of dry-land strength training vs. an electrical stimulation program on swimmers. Twenty-four national-level swimmers were randomly assigned to 3 groups: the dry-land strength training program (S), the electrical stimulation training program (ES), and the control (C) group. The training program lasted 4 weeks. The subjects were evaluated before the training, at the end of the training program, and 4 weeks later. The outcome values ascertained were peak torque during arm extension at different velocities (from -60 to 180°·s(-1)) using an isokinetic dynamometer and performance, stroke rate, and stroke length during a 50-m front crawl. A significant increase in swimming velocity and peak torque was observed for both S and ES at the end of the training and 4 weeks later. Stroke length increased in the S group but not in the ES group. However, no significant differences in swimming velocity between S and ES groups were observed. No significant changes occurred in the C group. Programs combining swimming training with dry-land strength or electrical stimulation programs led to a similar gain in sprint performance and were more efficient than swimming alone.     

Acute cardiorespiratory responses of hypertensive rats to swimming and treadmill exercise

The acute cardiorespiratory responses of spontaneously hypertensive rats (SHR) to swimming and running exercise was investigated because SHR populations are hyperresponsive to external stimuli, of the paucity of existing data, and of the uncertainty on the role of exercise stimuli for training adaptations to occur. Male rats were assigned to one of five groups (n = 5-6/group) and designated as controls (C), inexperienced or naive free swimmers (NFS), experienced free swimmers (FS), experienced weighted swimmers (WS) (attached weights equal to 2% of their body weight) or experienced runners (R) who ran at an intensity of 75% of their VO2max. After 75 min in the water, all groups were acidotic and hypercapnic with the WS experiencing the greatest changes. Heart rate (HR) was increased in all swimmers during the initial 10 min, but declined thereafter, and after 75 min, the HR of WS (348 +/- 1 beats/min) was significantly lower than the C group (416 +/- 22 beats/min). At the same time interval, mean arterial blood pressure (MAP) was decreased in all swimming groups to values lower than the C animals. In addition, an exaggerated diving reflex was frequently noted when the rats were submerged. When the magnitudes of the changes were evaluated in the swimming animals they were directly associated with their submergence times, i.e., during 65-75 min of the swim, NFS, FS, and WS were submerged for 43, 46, and 66% of their total swim time, respectively. In sharp contrast to the swimmers, the runners exhibited increases in HR and MAP with their blood gas measurements being indicative of hyperventilation. We concluded that swimming as an exercise mode for hypertensive rats is best served to study the combined effects of excitement, prolonged submergence, and the consequences of the diving reflex.     

Assisted and resisted sprint training in swimming

This study was undertaken to determine whether the resisted-sprint in overstrength (OSt) or the assisted-sprint in overspeed (OSp) could be efficient training methods to increase 100-m front crawl performance. Thirty-seven (16 men, 21 women) competition-level swimmers (mean +/- SD: age 17.5 +/- 3.5 years, height 173 +/- 14 cm, weight 63 +/- 14 kg) were randomly divided into 3 groups: OSt, OSp, and control (C). All swimmers trained 6 days per week for 3 weeks, including 3 resisted or assisted training sessions per week for the groups OSt and OSp respectively. Elastic tubes were used to generate swimming overstrength and overspeed. Three 100-m events were performed before, during, and after the training period. Before each 100-m event, strength of the elbow flexors and extensors was measured with an isokinetic dynamometer. Stroke rate and stroke length were evaluated using the video-recorded 100-m events. In the OSt group, elbow extensor strength, swimming velocity, and stroke rate significantly increased (p < 0.05), while stroke length remained unchanged after the 3-week training period. In the OSp group, stroke rate significantly increased (p < 0.05) and stroke length significantly decreased (p < 0.05) without changes in swimming velocity. No significant variations in the C group were observed. Both OSt and OSp proved to be more efficient than the traditional training program. However, the OSt training program had a larger impact on muscle strength, swimming performance, and stroke technique than the OSp program.