Identification of Accelerometer Nonwear Time and Sedentary Behavior

Abstract

This study was designed to investigate the swimming endurance trainability of smokers as compared to nonsmokers. Nonsmokers (N = 47) and smokers (N = 34) of college age were selected from intermediate swimming classes and timed while swimming distances of 100 yd. and 200 yd. prior to participation in an 8-week training program. After 4 weeks of training, swimming times were again recorded for these same distances. At the end of eight weeks, swimming times were taken for distances of 100, 200, and 400 yards. The mean changes of both smokers and nonsmokers during the pretraining to 4-week period, the 4-week to 8-week period, and the pretraining to 8-week period were all significant at the .05 level. However, no significant differences were found between the mean swimming times of smokers and nonsmokers for any of the pretraining, 4-week, or 8-week distances.     

Acute responses of biomechanical parameters to different sizes of hand paddles in front-crawl stroke

Abstract

This study investigated the acute effects of different sizes of paddles on the force-time curve during tethered swimming and swimming velocity in front-crawl stroke. Fourteen male swimmers (20.0 ± 3.7 years; 100-m best time: 53.70 ± 0.87 s) performed two 10-s maximal efforts in tethered swimming to obtain peak force, average force, impulse, rate of force development, stroke duration and time to peak force. Swimming velocity, stroke rate and stroke length were obtained from two 25-m maximal swims. Both tests were repeated in five conditions: free swimming, wearing small (280 cm ² ), medium (352 cm ² ), large (462 cm ² ) and extra-large (552 cm ² ) hand paddles. Compared to free swimming, paddles provided significant increases of peak force (medium: 11.5%, large: 16.7%, extra-large: 21.7%), impulse (medium: 15.2%, large: 22.4%, extra-large: 30.9%), average force (medium: 5.1%, large: 7.5%), rate of force development (extra-large: 11.3%), stroke duration (medium: 9.3%, large: 11.8%, extra-large: 18.5%), time to peak force (medium: 11.1%, large: 15.9%, extra-large: 22.1%), swimming velocity (medium: 2.2%, large: 3.2%, extra-large: 3.7%) and stroke length (medium: 9.0%, large: 9.0%, extra-large: 14.8%), while stroke rate decreased (medium: –6.2%, large: –5.5%, extra-large: –9.5%). It is concluded that medium, large and extra-large paddles influence the force-time curve and change swimming velocity, suggesting these sizes may be useful for force development in water.     

Index for Volume 51 (1980)

Abstract

Eight college swimmers were tested on a swimming ergometer to investigate the effects of body position on land and immersion in the water on the heart rate recovery after swimming exercise. The subjects swam at a predetermined work load for 5 min. and then assumed one of the four conditions for recovery (erect and supine on the deck, motionless and swimming in the water). Heart rates were recorded for the 3 min. of recovery. After the allowance for recovery, the subject was timed for a 200-yd. swim. No statistically significant differences were noted when comparing the recovery heart rates for the four conditions. The same was found true when comparing the 200-yd. swim times. It was noted that the swim was felt to be harder when recovery was completed in an erect or supine position than after light exercise in the water.     

Increased exhaled breath condensate 8-isoprostane after a swimming session in competitive swimmers

Objectives: This study aimed to evaluate the levels of 8-isoprostane (8-IsoP) in the airways of competitive swimmers at baseline and after a swimming session according to their airway responsiveness. Methods: Twenty-three swimmers and six lifeguards had a baseline spirometry and bronchoprovocative challenges. During a second visit, swimmers performed a usual swimming session while lifeguards stayed in the same pool environment for the same time period. Forced expiratory volume in one second (FEV₁) was measured before and 5 min after the end of the session. Exhaled breath condensate (EBC) was sampled before and 10 min after the session and EBC 8-IsoP levels were analysed by enzyme immunoassay. Change in EBC 8-IsoP from baseline to post-swimming session was calculated. Results: We observed no relationships between airway hyper-responsiveness and 8-IsoP values before or after swimming in swimmers. The levels of 8-IsoP were significantly higher after the training session (mean value 2.9, s?=?0.5 pg?mL^?1) than at baseline (mean value 1.9, s?=?0.4 pg?mL^?1) in swimmers only (p?=?.012). EBC 8-IsoP levels after the swimming session significantly correlated with the percent change in FEV₁ after swimming. Conclusions: EBC 8-IsoP levels were increased after training in swimmers but not in lifeguards, suggesting that exercise-induced hyperpnoea in a chlorinated pool environment increases airways oxidative stress.     

Personality Traits of Faster and Slower Competitive Swimmers

Abstract

This study made the comparison of swimmers ranked according to swimming ability as determined by actual time tests in events used in NCAA high school dual meets with personality traits as measured by the Thurstone temperament schedule. The purpose was to add to the knowledge of characteristics of swimmers by determining if the factors within the individual which make a boy a better swimmer correlate significantly with the measured personality traits. Twenty-one swimmers were timed throughout the swimming season on each of the swimming events and the rank of each swimmer calculated. Each swimmer was given the personality test. Statistical analysis of the rankings of these seven personality traits was made in comparison to the swimming rank of the swimmers in the various strokes. Three rank difference correlations were found significant at the .05 level, indicating a tendency for rank of swimming performance to correspond with rank of personality variable. The dominant trait was positively correlated with 100-yard freestyle ranking. Negative correlations were found with the sociable trait and the 100-yard breaststroke and with the reflective trait and 200-yard freestyle.     

Cross-Validation of the Revised Motivation for Physical Activity Measure in Active Women

Abstract

The five different training methods used in this study consisted of various proportions of swimming and of weight training exercises. Sixty subjects were divided into five equated groups. Each group was exposed to a different treatment over a period of six weeks. Tests of swimming speed were administered at the beginning of the experiment, and at the end of each week. All five treatments resulted in significant swimming improvements, but none of the treatments were significantly more effective than the other treatments.     

Effect of a Single Day's Swimming on Selected Components of Athletic Performance

Abstract

The purpose of this investigation was to study the effect of swimming on selected components of athletic performance as measured by the following tests: back strength, leg strength, bicycle ergometer (combination of strength and endurance, but predominantly endurance), and vertical jump (explosive power). Subjects were pretested for three days on each test, after which they participated in 45 minutes of swimming, and performance was tested oh one test one hour after the swim on any given day. A single day's swimming was found to significantly affect the vertical jump, but other performance tests were not affected.     

Effects of Swimming and Walking on Exercise Recovery and Subsequent Swim Performance

Abstract

Six female collegiate swimmers were used to evaluate the hypothesis that the recovery procedure after exercise will not only affect subsequent performance, but will also affect the recovery process after the subsequent performance. Each swimmer exercised for two minutes at 90% [Vdot]O₂ max on a swimming ergometer, recovered for 15 minutes by walking on land or swimming, then swam 200 yds. for time. Oxygen uptake was measured for 15 minutes after the 200 yd. swim. Venous blood, obtained after the ergometry swim, and before and after the 200 yd. swim, was analyzed for lactate. Two hundred yard swim times were not significantly affected by either the walking or swimming recovery procedures. Blood lactate after the ergometry swim averaged 96.7 ± 18 mg/100 ml. The swimming recovery reduced the lactate levels by 53.3% compared to a 38.5% reduction during the walking recovery. Significant differences in blood lactate were also noted after the 200 yd. swim, with the trials in which swimming recovery protocol was used yielding less than the trials involving the walking recovery (99 ± 8 mg/100 ml compared to 113 ± 8 mg/100 ml, respectively). The post 200 yd. swim oxygen uptakes averaged 7.74 ± 1.51 liters and were not affected by protocol. It was concluded that a 15 minute recovery period may be sufficient for repeated bouts of high intensity work lasting less than three minutes. It was also concluded that self-selection of the mode of recovery is not always the most effective for removal of blood lactate.     

Relationship of Organ Weight and Swimming Performance in the Albino Rat

Abstract

The relationship between organ weight and swimming capacity was determined in 42 male albino rats. Upon completion of a 4-week training program, the animals were forced to swim to exhaustion with 2 percent of the body weight attached. They were sacrificed and specific gravity and organ weights determined. The results warrant the following conclusions: A significant (p < .05) but low correlation exists between the relative weight of the spleen and lungs with swimming performance. The correlation of relative heart weight and swimming performance approached statistical significance (p < .06). Attaching a weight proportional to the body weight to increase the energy cost of swimming penalizes the heavier animals. Correcting for the inverse relationship between body weight and swim time does not alter appreciably the relationships between organ weights and swim time.     

Assessment of Differing Definitions of Accelerometer Nonwear Time

Abstract

Twelve college and high school varsity male swimmers swam 200 yd. for time once a day for 16 days following the ingestion of a large meal (673 g). Each subject performed under rotating experimental conditions, which involved a post-meal rest interval of ½ hr., 1 hr., 2 hr., or no eating for at least 3 hr. before swimming. A nonsignificant F of .53 was obtained when the data were subjected to a single-factor with repeated measures analysis of variance.

It was concluded that swimming performance time was not affected by the time interval between eating and swimming. No stomach cramps were reported; most cases of stomach nausea occurred in the ½-hr. interval group, and scattered minor physical disturbances occurred under the other conditions.     

A 3D kinematic analysis of breathing patterns in competitive swimmers

Abstract

The purpose of this paper was to understand which differences long-term swimming training can cause on trunk mechanics during breathing and how these differences are related to the years of swimming training. The variations and coordination among trunk compartments were considered as target movement patterns. Video-based plethysmography was utilised for data acquisition and pre-processing. A group of swimmers, who followed a long-term intensive swimming training previously to this study, was compared with a non-swimmer control group. The participants of both groups performed quiet breathing and vital capacity tests. From the compartmental volumes associated with each breathing curves, the relative amplitude and cross-correlation among these volumetric time-varying signals were calculated, in order to analyse the relative partial volume variation and the coordination among trunk compartments involved in respiration. The results of a Mixed-ANOVA test (P ≤ 0.05) revealed higher coefficient of variation (P < 0.001) and correlations among trunk compartments in the swimmers group when vital capacity was performed. Significant linear regression was found between the years of swim training and the coefficients of variation and correlation. The results suggest that after long periods of intensive swim training, athletes might develop specific breathing patterns featuring higher volume variations in the abdominal region and more coordination among compartments involved in forced respiratory tasks such as vital capacity.     

Research on Teaching in Physical Education: Questions and Comments

Abstract

The purpose of this investigation was to study the effect of swimming on the learning and performance of two complex gross motor skills. Forty college men were matched on the basis of a pre-test and formed into experimental and control groups. The experimental group learned the two selected skills in addition to swimming, whereas the control group learned only the selected skills. Two scoring systems were used, and findings indicated no significant difference between groups.     

Does ankle joint flexibility affect underwater kicking efficiency and three-dimensional kinematics?

ABSTRACT

Ankle flexibility is critical to obtain a high swimming velocity in undulatory underwater swimming (UUS). The present study investigated the Froude (propelling) efficiency and three-dimensional (3D) kinematics of human UUS following the extrinsic restriction of the ankle by tape application. In Experiment 1, swimmers (9 male and 8 female college swimmers) performed UUS trials involving normal swimming (Normal) and swimming with tape application at the ankle (Tape). Kicking frequency was controlled in both settings. UUS kinematics were obtained with a two-dimensional motion analysis. Swimming velocity significantly decreased during swimming with tape application compared with that during normal swimming (Normal, 1.33 m·s^?1; Tape, 1.26 m·s^?1, p < 0.05). The Froude efficiency was not affected (Normal, 0.77; Tape, 0.76), and ankle plantar angle did not decrease during swimming (Normal, 159.02°; Tape, 160.38°). In Experiment 2, lower limb rotations of a male swimmer were analysed using 3D motion analysis under the same conditions as Experiment 1. An insufficient forefoot rotation was observed during downstroke kicks (the phase of the highest acceleration to forward direction). These findings suggest that UUS velocity is affected by the mobility of end effector.     

Evaluation of mean power spectral frequency of EMG signal during 100 metre crawl

Abstract

The aim of our study was to compare mean frequency (MNF) decrease in some upper body muscles during a 100-metre all-out crawl by using two different normalization methods: firstly, when MNF at the end of swimming (MNF_Send) was normalized with respect to its initial value at the beginning and expressed with a fatigue index (FI) labelled FI_start, and secondly when MNF_min was used to calculate FI_min. MNF_min presented the lowest MNF obtained during isometric contractions until exhaustion executed on land after swimming for each of three observed muscles – triceps brachii (TB), latissimus dorsi (LD) and pectoralis major (PM). Eleven experienced swimmers participated in the study and surface electromyography (EMG) signals from TB, the upper and lower parts of LD (LD1 and LD2 respectively) and the upper and lower parts of PM (PM1 and PM2 respectively) were recorded during both swimming and isometric contractions. Results showed no differences in FI_start; however, when FI_min values were compared differences between the muscles were found (P<0.05). The triceps brachii (TB) and the upper part of the latissimus dorsi muscles (LD1) showed the lowest FI_min (40.0±15.7 and 40.7±24.4 respectively), which implied that MNF_Send obtained from these muscles most closely approached their respective MNF_min values during swimming. This might suggest that these muscles fatigued more than other observed muscles. The use of a different type of muscle contraction for calculating FI_min (isometric versus dynamic) might represent a drawback to our study, but this approach could be acceptable when between-muscle comparisons are made.     

Swimming

Abstract

The effect on drag of a Speedo Fast‐skin suit compared to a conventional suit was studied in 13 subjects (6 males, 7 females) swimming at different velocities between 1.0 and 2.0 m?s^‐1. The active drag force was directly measured during front crawl swimming using a system of underwater push‐off pads instrumented with a force transducer (MAD system). For a range of swimming speeds (1.1, 1.3, 1.5 and 1.7 m?s^‐1), drag values were estimated. On a group level, a statistically non‐significant drag reduction effect of 2% was observed for the Fast‐skin suit (p = 0.31). Therefore, the 7.5% reduction in drag claimed by the swimwear manufacturer was not corroborated.     

Pacing in lane-based head-to-head competitions: A systematic review on swimming

ABSTRACT

Athletes’ energy distribution over a race (e.g. pacing behaviour) varies across different sports. Swimming is a head-to-head sport with unique characteristics, such as propulsion through water, a multitude of swimming stroke types and lane-based racing. The aim of this paper was to review the existing literature on pacing behaviour in swimming. According to PRISMA guidelines, 279 articles were extracted using the PubMed and Web of Science databases. After the exclusion process was conducted, 16 studies remained. The findings of these studies indicate that pacing behaviour is influenced by the race distance and stroke type. Pacing behaviours in swimming and time-trial sports share numerous common characteristics. This commonality can most likely be attributed to the lane-based racing set-up. The low efficiency of swimming resulting from propulsion through the water induces a rapid accumulation of blood lactate, prompting a change in swimmers’ biomechanical characteristics, with the goal of minimising changes in velocity throughout the race. Although the literature on youth swimmers is scarce, youth swimmers demonstrate more variable pacing profiles and have more difficulty in selecting the most beneficial energy distribution.     

Neurogranin as an important regulator in swimming training to improve the spatial memory dysfunction of mice with chronic cerebral hypoperfusion

BackgroundVascular cognitive impairment caused by chronic cerebral hypoperfusion (CCH) has become a hot issue worldwide. Aerobic exercise positively contributes to the preservation or restoration of cognitive abilities; however, the specific mechanism has remained inconclusive. And recent studies found that neurogranin (Ng) is a potential biomarker for cognitive impairment. This study aims to investigate the underlying role of Ng in swimming training to improve cognitive impairment.MethodsTo test this hypothesis, the clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) system was utilized to construct a strain of Ng conditional knockout (Ng cKO) mice, and bilateral common carotid artery stenosis (BCAS) surgery was performed to prepare the model. In Experiment 1, 2-month-old male and female transgenic mice were divided into a control group (wild-type littermate, n = 9) and a Ng cKO group (n = 9). Then, 2-month-old male and female C57BL/6 mice were divided into a sham group (C57BL/6, n = 12) and a BCAS group (n = 12). In Experiment 2, 2-month-old male and female mice were divided into a sham group (wild-type littermate, n = 12), BCAS group (n = 12), swim group (n = 12), BCAS + Ng cKO group (n = 12), and swim + Ng cKO group (n = 12). Then, 7 days after BCAS, mice were given swimming training for 5 weeks (1 week for adaptation and 4 weeks for training, 5 days a week, 60 min a day). After intervention, laser speckle was used to detect cerebral blood perfusion in the mice, and the T maze and Morris water maze were adopted to test their spatial memory. Furthermore, electrophysiology and Western blotting were conducted to record long-term potential and observe the expressions of Ca²⁺ pathway-related proteins, respectively. Immunohistochemistry was applied to analyze the expression of relevant markers in neuronal damage, inflammation, and white matter injury.ResultsThe figures showed that spatial memory impairment was detected in Ng cKO mice, and a sharp decline of cerebral blood flow and an impairment of progressive spatial memory were observed in BCAS mice. Regular swimming training improved the spatial memory impairment of BCAS mice. This was achieved by preventing long-term potential damage and reversing the decline of Ca²⁺ signal transduction pathway-related proteins. At the same time, the results suggested that swimming also led to improvements in neuronal death, inflammation, and white matter injury induced by CCH. Further study adopted the use of Ng cKO transgenic mice, and the results indicated that the positive effects of swimming training on cognitive impairments, synaptic plasticity, and related pathological changes caused by CCH could be abolished by the knockout of Ng.ConclusionSwimming training can mediate the expression of Ng to enhance hippocampal synaptic plasticity and improve related pathological changes induced by CCH, thereby ameliorating the spatial memory impairment of vascular cognitive impairment.     

Swimming intensity during triathlon: A review of current research and strategies to enhance race performance

Abstract

The swim section of Sprint- and Olympic-distance triathlon race formats is integral to the success of subsequent cycle and running disciplines, and to overall race performance. The current body of swimming-based triathlon research suggests that the energy used, and the positioning gained among competitors during the swim, is important in determining the success of an athlete's race, especially professional athletes in draft-legal settings. Furthermore, by swimming at a reduced intensity, it has been shown that the performance of the subsequent disciplines may be enhanced. However, reductions in energy output can be obtained without compromising swimming speed. This review highlights the importance of swimming intensity during a triathlon and how it impacts on the ensuing cycle and run. Furthermore, consideration is given to current methods used to manipulate swimming performance.     

Response Timing Accuracy of Long-Distance Movements

Abstract

The purpose of the study was to compare the effectiveness of the Red Cross and Silvia methods of teaching beginning swimming. College women (N = 76), who were beginners in swimming, served as subjects. Pretests indicated no differences among the four classes prior to instruction. Reliability coefficients of the post-tests for distance and survival time (test-retest method) ranged from .70 to .98. ANOVA procedures utilizing front crawl distance, back crawl distance, survival time, and length of time required to pass the Red Cross combined tests as dependent variables resulted in superiority of the Silvia method over the Red Cross method in each analysis.