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PubMed1991

Effects of swimming and land exercises versus swimming and water exercises on body composition of college students.

The purpose of this study was to examine the effects of 2 different swimming and calisthenic exercise programs on body composition and swim performance. Subjects were forty-two students (M = 19; F = 23; mean age = 20.8 yr). The experimental groups (Swim-Land [SL], n = 14; Swim-Water, [SW], n = 16) participated in 35-40 min exercise sessions which consisted of a 5-10 min warm-up, 15-20 min of swimming, and 10-15 min of calisthenics three times per week for 8 weeks. The SL experimental group performed calisthenics on land with surgical tubing while the SW experimental group performed comparable calisthenics in the water. Subjects were pretested and posttested utilizing hydrostatic weighing to determine body density and calculate percent fat. Skinfold measures and the 12-min swim for distance were also measured. Results indicated a significant 20% increase in swim performance in both experimental groups (SL = 455 +/- 144 m to 553 +/- 114 m; SW = 465 +/- 122 m to 556 +/- 123 m; p less than 0.05) but no difference between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Composition↗
PubMed1998

Curvature of Swimming Fish Midlines as an Index of Muscle Strain Suggests Swimming Muscle Produces Net Positive Work.

The axial muscle used in steady swimming by fish is geometrically complex and this has required the study of in vivo muscle swimming mechanics to be done with largely inferential techniques. Currently there is some debate concerning the variation in muscle function in different regions of the body, and the importance of negative work production by muscles in posterior locations. We have used video taped kinematics of steady swimming in mackerel and then analysed the lateral flexion of the body that is thought to reflect the cycle of length change in the axial muscles. A comparison of several of the techniques used in the past to estimate muscle length changes are shown not to be equivalent. Specifically, we find that peak values of lateral deflection of the body are not correlated in time or axial position with peaks in curvature of the body midline. This is important because the timing of the muscle strain cycle is often inferred from such information. Having documented this observation in a swimming mackerel, we use analytical geometry to show that this result is a consequence of the curves that describe swimming fish midlines. Since this observation is shown to be the geometric consequence of an amplitude envelope that is not constant, it should therefore apply to other animals that propel themselves with axial undulations of increasing amplitude. Our minor result is that care must be taken when estimating the phase of swimming muscle strain from kinematics. Our major results is that appreciation of the geometric character of the kinematics these fish adopt may resolve much of the current debate concerning the mechanical performance of swimming muscle in fish. Specifically, using our estimate of the phase of muscle shortening and data on EMG timing in the mackerel we conclude that all axial muscles are activated before peak length and in a manner that should produce net positive work within each shortening cycle.Copyright 1998 Academic Press

Journal Article↗
PubMed1993

Investigation in real time of the effect of gravitation on human spermatozoa and their tendency to swim-up and swim-down.

To investigate in real time if and how natural gravity affects rates of swim-up and swim-down of human spermatozoa, samples of motile or immobilized spermatozoa in a sealed mini-chamber were placed vertically on a 90 degrees tilted microscope. The mode of their sedimentation, as well as the difference in the rate of their swimming up and down, were observed directly over 30 min and analysed from photomicrographs. Under the influence of natural gravity force, most immobilized spermatozoa turned their heads down in about 5 min and then sank slowly at an average speed of 0.2 mu/s. The number of motile spermatozoa that swam down was 5-6 times more than those swimming up. It can be implied that in spite of the mild force exerted by 1 g on suspended spermatozoa in comparison to the high g force obtained by centrifugation, the overall effect of gravity on the rate of swimming up or down becomes dominant. Gravity causes the sperm heads to turn downward after which the oriented spermatozoa continue to move down by their own tail movements, causing accumulation of motile spermatozoa at the bottom. This may explain why in some recent studies swim-down was superior to the swim-up procedure during sperm separation by self-migration.

Gravitation↗
PubMedDate not supplied

Fungal contamination of the floors of swimming pools, particularly subtropical swimming paradises.

We compared the level of dermatophyte contamination of the floors of traditional swimming pools and of subtropical swimming paradises, a new type of indoor swimming pool introduced in Belgium in 1981. From the results of routine hygiene inspections over several years and of a comparative study, we can conclude that the floors of subtropical swimming pools are much more highly contaminated by dermatophytes than the floors of traditional swimming pools. This higher degree of contamination is due to the huge number of visitors, the complexity of construction, the choice of materials and the long opening hours. In both types of swimming pools, the predominant species was Trichophyton mentagrophytes var. interdigitale, followed by T. rubrum. Other dermatophytes, such as Microsporum canis and M. gypseum, were isolated sporadically.

Belgium↗
PubMed2004

Locomotory behaviour and post-exercise physiology in relation to swimming speed, gait transition and metabolism in free-swimming smallmouth bass (Micropterus dolomieu).

We examined swimming behaviour, gait recruitment and post-exercise muscle glycogen, muscle lactate, plasma lactate and oxygen consumption in smallmouth bass (Micropterus dolomieu; 24-38 cm fork length) that voluntarily ascended a 25 m raceway against water velocities ranging from 40 to 120 cm s(-1). Physiological parameters were referenced to additional measurements made following exhaustive exercise in a static tank and aerobic exercise in a swim tunnel. Maximum speeds maintained exclusively using a steady gait in the raceway ranged from 53.6 to 97.3 cm s(-1) and scaled positively with fish length. Minimum swimming speeds maintained exclusively through recruitment of an unsteady gait were also positively correlated to fish length and ranged from 81.4 to 122.9 cm s(-1). Fish switched between steady and unsteady swimming at intermediate speeds. Smallmouth bass always maintained a positive ground speed in the raceway; however, those that primarily swam using a steady gait to overcome low to moderate water velocities (20-50 cm s(-1)) maintained mean ground speeds of approximately 20 cm s(-1). By contrast, mean ground speeds of fish that primarily recruited an unsteady locomotory gait increased significantly with water velocity, which resulted in an inverse relationship between exercise intensity and duration. We interpret this behaviour as evidence that unsteady swimming was being fuelled by the limited supply of anaerobic substrates in the white muscle. This hypothesis is supported by the fact that unsteady swimming fish showed significantly lower muscle glycogen levels, higher lactate concentrations (muscle and plasma) and higher post-exercise oxygen consumption rates compared with fish that used a steady gait. The reduction in passage time achieved by fish using an unsteady gait allowed them to ascend the raceway with relatively minor post-exercise metabolic imbalances, relative to individuals chased to exhaustion.

Animals↗
PubMed2005

Optimal swim speeds for traversing velocity barriers: an analysis of volitional high-speed swimming behavior of migratory fishes.

Migrating fish traversing velocity barriers are often forced to swim at speeds greater than their maximum sustained speed (U(ms)). Failure to select an appropriate swim speed under these conditions can prevent fish from successfully negotiating otherwise passable barriers. I propose a new model of a distance-maximizing strategy for fishes traversing velocity barriers, derived from the relationships between swim speed and fatigue time in both prolonged and sprint modes. The model predicts that fish will maximize traversed distance by swimming at a constant groundspeed against a range of flow velocities, and this groundspeed is equal to the negative inverse of the slope of the swim speed-fatigue time relationship for each mode. At a predictable flow velocity, they should switch from the optimal groundspeed for prolonged mode to that for sprint mode. Data from six migratory fish species (anadromous clupeids: American shad Alosa sapidissima, alewife A. pseudoharengus and blueback herring A. aestivalis; amphidromous: striped bass Morone saxatilis; and potomodromous species: walleye (previously known as Stizostedion vitrium) and white sucker Catostomus commersonii) were used to explore the ability of fish to approximate the predicted distance-maximizing behaviors, as well as the consequences of deviating from the optima. Fish volitionally sprinted up an open-channel flume against fixed flow velocities of 1.5-4.5 m s(-1), providing data on swim speeds and fatigue times, as well as their groundspeeds. Only anadromous clupeids selected the appropriate distance-maximizing groundspeed at both prolonged and sprint modes. The other three species maintained groundspeeds appropriate to the prolonged mode, even when they should have switched to the sprint optima. Because of this, these species failed to maximize distance of ascent. The observed behavioral variability has important implications both for distributional limits and fishway design.

Animals↗
PubMed2001

How the body contributes to the wake in undulatory fish swimming: flow fields of a swimming eel (Anguilla anguilla).

Undulatory swimmers generate thrust by passing a transverse wave down their body. Thrust is generated not just at the tail, but also to a varying degree by the body, depending on the fish's morphology and swimming movements. To examine the mechanisms by which the body in particular contributes to thrust production, we chose eels, which have no pronounced tail fin and hence are thought to generate all their thrust with their body. We investigated the interaction between body movements and the flow around swimming eels using two-dimensional particle image velocimetry. Maximum flow velocities adjacent to the eel's body increase almost linearly from head to tail, suggesting that eels generate thrust continuously along their body. The wake behind eels swimming at 1.5 Ls(-1), where L is body length, consisted of a double row of double vortices with little backward momentum. The eel sheds two vortices per half tail-beat, which can be identified by their shedding dynamics as a start-stop vortex of the tail and a vortex shed when the body-generated flows reach the 'trailing edge' and cause separation. Two consecutively shed ipsilateral body and tail vortices combine to form a vortex pair that moves away from the mean path of motion. This wake shape resembles flow patterns described previously for a propulsive mode in which neither swimming efficiency nor thrust is maximised but sideways forces are high. This swimming mode is suited to high manoeuvrability. Earlier recordings show that eels also generate a wake reflective of maximum swimming efficiency. The combined findings suggest that eels can modify their body wave to generate wakes that reflect their propulsive mode.

Anguilla↗
PubMed1993

Modulation of swimming behavior in the medicinal leech. I. Effects of serotonin on the electrical properties of swim-gating cell 204.

The effects of serotonin on the electrical properties of swim-gating neurons (cell 204) were examined in leech (Hirudo medicinalis) nerve cords. Exposure to serotonin decreased the threshold current required to elicit swim episodes by prolonged depolarization of an individual cell 204 in isolated nerve cords. This effect was correlated with a more rapid depolarization and an increased impulse frequency of cell 204 in the first second of stimulation. In normal leech saline, brief depolarizing current pulses (1 s) injected into cell 204 failed to elicit swim episodes. Following exposure to serotonin, however, identical pulses consistently evoked swim episodes. Thus, serotonin appears to transform cell 204 from a gating to a trigger cell. Serotonin had little effect on the steady-state current-voltage relation of cell 204. However, serotonin altered the membrane potential trajectories in response to injected current pulses and increased the amplitude of rebound responses occurring at the offset of current pulses. These changes suggest that serotonin modulates one or more voltage dependent conductances in cell 204, resulting in a more rapid depolarization and greater firing rate in response to injected currents. Thus, modulation of intrinsic ionic conductances in cell 204 may account in part for the increased probability of swimming behavior induced by serotonin in intact leeches.

Animals↗
PubMed1994

Modulation of swimming behavior in the medicinal leech. IV. Serotonin-induced alteration of synaptic interactions between neurons of the swim circuit.

Serotonin enhances the expression of swimming in the medicinal leech Hirudo medicinalis. These two reports examine the physiological causes underlying this modulation. The initial paper (Mangan et al. 1994) demonstrated that serotonin enhanced the participation of inhibitory swim motor neurons (MNs) in the generation of the swimming rhythm in the isolated nerve cord. In experiments reported here, we examined whether synaptic interactions between neurons of the swim circuit are altered by serotonin. Following exposure to 50 microM serotonin, pairwise intracellular recording revealed the presence of a time-dependent synaptic decrement. Synaptic decrement was characterized by: 1) a substantial decline in synaptic inhibition (half-decay time about 0.4 s) during constant presynaptic excitation; 2) a reduced half-time of recovery from synaptic inhibition; and 3) a strong dependence on the presynaptic neuron's membrane potential. We found little alteration in the physiology of synaptic transmission involving MNs following amine depletion in leech nerve cords. We propose that alterations in synaptic interactions resulting from exposure to elevated serotonin levels, coupled with the changes in MN cellular properties described earlier, are crucial to the increased efficacy of MNs in participating in generating and expressing the leech swimming rhythm.

Animals↗
PubMed1979

Swimming capacity of mice after prolonged treatment with psychostimulants. III. Effect of fencamfamine on swimming endurance and availability of metabolic substrates.

The effect of long-term treatment with fencamfamine on swimming endurance and availability of metabolic substrates was investigated in mice. Fencamfamine (14 micrograms/g per day orally for 6 weeks) reduced maximum swimming capacity by more than 40%. This effect could not be attributed to motor incoordination or a diminution of pre-swimming levels of metabolic substrates such as liver and muscle glycogen or blood glucose and non-esterfied fatty acids. However, during swimming the hepatic and muscular glycogen stores were depleted more rapidly in the fencamfamine-treated animals. Thus it appears that fencamfamine leads more rapidly to a shortage of combustible substrates in the swimming animals.

Adipose Tissue↗
PubMed2004

Effects of various Eleutherococcus senticosus cortex on swimming time, natural killer activity and corticosterone level in forced swimming stressed mice.

The cortex of Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. has been used extensively in Russia, China, Korea and Japan as an adaptogen whose properties are the ability to increase as non-specific body resistance to stress and fatigue. Although it has been reported that Eleutherococcus senticosus has anti-fatigue and anti-stress actions, their actions are still unclear on the relationship between immune system, especially natural killer (NK) activity and endocrine system (corticosterone level). We compared the effects of the water extracts (A, B, C, D and E) of five Eleutherococcus senticosus cortex on the swimming time, NK activity and blood corticosterone level using forced swimming stressed mice. Among five kinds, C, D and E extracts significantly prolonged the swimming time. C and D extracts inhibited the reduction of NK activity and the corticosterone elevation induced by forced swimming. The contents of eleutheroside E, isoflaxidin and eleutherosides B plus E were in the order C > D > E > B > A and C > E > D > A > B extracts, respectively. Therefore, it is suggested that eleutheroside E may be contributed to the anti-fatigue action, the recovery of the reduction of NK activity and the inhibition of corticosterone elevation induced by swimming stress.

Animals↗
PubMed1986

[Swimming after myocardial infarct. Oxygen saturation, pulmonary arterial and capillary pressure in underwater immersion and during swimming after myocardial infarct].

Pulmonary arterial (PA) and pulmonary capillary (PC) pressures and oxygen saturation were measured over a 5-minute period on immersion in water and during swimming in four symptom-free men (aged 52-58 years) who had sustained a transmural infarct 6-10 weeks previously. Measurements were made through an indwelling flow-guided percutaneously introduced catheter. The speed of swimming was 20-25 m/min. Static pressures on immersion up to the neck rose up to 23 mm Hg, on diving to five times as much above the resting recumbent value. Mean PC values after five minutes of swimming rose in all four subjects above those obtained after a 5-minute 100 W exercise: they were similar to the diastolic pressures. But the oxygen saturations on swimming were in all patients higher than after tread-wheel exercise. All patients felt swimming to be easier than the ergometric exercise. It is concluded that noninvasive methods, such as X-rays, ergometry and echocardiography, are not sufficient for estimating volume stress induced by immersion in water. Cardiac arrhythmias did not occur.

Exercise Test↗
PubMed2003

Benefits of swimming in asthma: effect of a session of swimming lessons on symptoms and PFTs with review of the literature.

A study involving eight children with moderate persistent asthma was undertaken to determine whether standard swimming lessons improved symptoms and pulmonary function tests (PFTs) in asthmatic children. Five children ages 7-12 years old with moderate persistent asthma were randomized to a swimming lesson group (5- to 6-week session) and three to a control group. Both groups completed pre- and poststudy period PFTs and symptom questionnaires. Swimming lessons did not produce a significant change in asthma symptoms or PFTs. Review of previous literature found that swimming has been shown to have definite benefits in improving cardiorespiratory fitness in asthmatic children. Swimming has been shown to be less asthmogenic than other forms of exercise. Some studies have also shown improvement in asthma symptoms in children participating in exercise programs.

Asthma↗
PubMed1967

Swimming sea anemones of Puget Sound: swimming of Actinostola new species in response to Stomphia coccinea.

Swimming as a response of the sea anemone Actinostola new species can be elicited as a result of contact with the submarginal surface of another swimming sea anemone Stomphia coccinea. However, Stomphia does not swim as a result of contact with Actinostola. In all other known respects, swimming is caused in both species by the same stimuli, including certain starfishes, a nudibranch, and electrical stimuli. No agent that causes Actinostola to swim has been detected in extracts, rubbings, or dried matter from Stomphia.

Animals↗
PubMed1992

Screening of children with arrhythmias for arrhythmia development during diving and swimming--face immersion as a substitute for diving and exercise stress testing as a substitute for swimming.

We compared face immersion and exercise stress testing by diving and swimming as screening methods for arrhythmias induced by immersion in water. The subjects were 64 children with various arrhythmias who were tested using 5 methods: diving, swimming, face immersion in 25 degrees C water, face immersion in 6 degrees C water, and a treadmill exercise test. Significant arrhythmias occurred during diving or swimming in 51 children, with 44 developing arrhythmias while diving. Both tachyarrhythmias and bradyarrhythmias were seen during diving, but 17 children who also showed significant arrhythmias while swimming mostly had tachyarrhythmias. A comparison with the incidence of arrhythmias produced by diving showed that face immersion in cold water had a sensitivity of 88.6%, a specificity of 85.0%, a predictive value of 92.9%, and an accuracy of 87.5%. Arrhythmias were alleviated in 12.5%, unchanged in 79.7%, and aggravated in 7.8% of the subjects. Face immersion thus appeared to be a useful and adequate screening substitute for diving. Exercise testing was also compared with swimming (sensitivity, 52.9%; specificity, 100%; predictive value, 100%; and accuracy, 87.5%). Arrhythmias were alleviated in 12.5% and unchanged in 87.5% of patients. Although exercise testing produced many false-negatives, all of the severe arrhythmias were reproduced.

Adolescent↗
PubMed1997

Compartmental shifts of calcium and magnesium as a result of swimming and swimming training in rats.

To describe accurately the mineral changes (Ca and Mg) provoked by swimming, the aims of this study were to analyze those tissues that, with regard to their mineral content, can better classify individuals performing both swimming until exhaustion and swimming as training and to know the shifts of these minerals between different tissues after a single session of swimming until exhaustion and after training. Wistar rats were distributed into 12 groups, six male and six female (N = 10): 1) control rest group (CR); 2) trained rest group (TR); 3) control exercise group (CE); 4) trained exercise group (TE); 5) control recovery group (CER) and 6) trained recovery group (TER). The most informative tissues of Ca and Mg compartmental shifts during exercise have been determined. Discriminant analysis selected heart Ca, muscle Ca and bone Ca, bone Mg, erythrocyte Mg, and serum Mg as the most significant variables. The animals were classified by means of two canonical axes: the first one relates to training situation and sex, and the second one shows the special characteristics of trained male rats. Another independent discriminant analysis applied to male and female groups separately showed that the first canonical axis (control/trained) is basically defined by heart Ca, bone Ca, and erythrocyte Mg (male), and by heart Ca, bone Ca, and bone Mg (female), while the second axis, related to the exercise situations, is defined by the serum Mg levels in both sexes. We think that discriminant analysis is a statistical method capable of explaining physiological processes and classifying individuals performing exercises of different length. It suggests that the homeostasis of Ca and Mg is somewhat different for males and females. Serum magnesium must be considered to distinguish exercise situations. The analysis of these tissues could inform us about the mineral status of the rats and then we could correct possible deficiencies in our research. In this work we have only found different mineral redistributions among tissues. The trained animals have a better mineral recovery capacity than the untrained ones. Training has a different physiological repercussion in male and female rats on the basis of their respective maximal swimming times after training and their mineral behavior.

Animals↗
PubMed1995

Tuning in to fish swimming waves: body form, swimming mode and muscle function

Most fish species swim with lateral body undulations running from head to tail. These waves run more slowly than the waves of muscle activation causing them, reflecting the effect of the interaction between the fish's body and the reactive forces from the water. The coupling between both waves depends on the lateral body shape and on the mechanical properties of the tail. During steady swimming, the length of each myotomal muscle fibre varies cyclically. The phase relationship between the strain (muscle length change) cycle and the active period (when force is generated) determines the work output of the muscle. The muscle power is converted to thrust either directly by the bending body or almost exclusively by the tail, depending upon the body shape of the species and the swimming kinematics. We have compared the kinematics and muscle activity patterns from seven species of fish with different body forms and swimming modes and propose a model which yields a consistent pattern, with at least three extremes. Subtle tuning of the phase relationship between muscle strain and activation cycles can lead to major changes in the way muscles function in different swimming modes.

Journal Article↗
PubMed2001

Sensory modification of leech swimming: interactions between ventral stretch receptors and swim-related neurons.

The neuronal circuits that generate the leech swimming rhythm comprise oscillatory interneurons that provide appropriately phased output to drive swim-related motoneurons. Within ganglia, these interneurons express three phases; between ganglia there exists a phase delay between homologs. Our earlier experiments revealed that stretch receptors embedded in the body wall participate in intersegmental coordination and setting intersegmental phases. To identify the basis for these sensory effects, we mapped interactions between a ventral stretch receptor and swim-related neurons. Connections between this receptor and motoneurons are weak and variable in quiescent preparations, but during fictive swimming stretch receptor activation modulates motoneuron oscillations, hence, these effects are polysynaptic, mediated by interneurons. We identified a strong, nonrectifying, and apparently direct electrical connection between the stretch receptor and oscillator neuron 33. The ventral stretch receptor also interacts with most of the other oscillatory interneurons, including inhibitory inputs to cells 28 and 208, excitatory input to the contralateral cell 115, and mixed input to the ipsilateral cell 115. These direct and indirect interactions can account for previously described effects of body-wall stretch on motoneuron activity. They also could mediate the previously described modification of intersegmental phase relationships by appropriately phased stretch receptor activation.

Animals↗