Effect of Swim Suit Design on Passive Drag

Mollendorf, Joseph C.; Termin, A.; Oppenheim, Eric; Pendergast, David R.

doi:10.1249/01.mss.0000128179.02306.57

Cited by 84 publications

(83 citation statements)

References 14 publications

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“…Thus both external and internal work are increased (79,80,107). Drag in water is velocity dependent (80) and increases as a function of kV n , where k is a constant, V is velocity, and n is the exponent of V, with n ϭ 1 for friction between the body and water, n ϭ 2 for the pressure to separate the water as the body moves through it (pressure drag), and n ϭ 4 for wave generation (67). Estimating the efficiency of underwater work is complicated, compared with terrestrial work, using a traditional approach (only considering external work) and yields a very low efficiency (about 5-8%) (80); during swimming the swimmer has to accelerate water when moving through it and also perform internal work moving body parts around the body center of gravity.…”

Section: Exercisementioning

confidence: 99%

The underwater environment: cardiopulmonary, thermal, and energetic demands

Pendergast¹,

Lundgren²

2009

Journal of Applied Physiology

133

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Pendergast DR, Lundgren CE. The underwater environment: cardiopulmonary, thermal, and energetic demands. J Appl Physiol 106: 276 -283, 2009. First published November 26, 2008 doi:10.1152/japplphysiol.90984.2008.-Water covers over 75% of the earth, has a wide variety of depths and temperatures, and holds a great deal of the earth's resources. The challenges of the underwater environment are underappreciated and more short term compared with those of space travel. Immersion in water alters the cardio-endocrine-renal axis as there is an immediate translocation of blood to the heart and a slower autotransfusion of fluid from the cells to the vascular compartment. Both of these changes result in an increase in stroke volume and cardiac output. The stretch of the atrium and transient increase in blood pressure cause both endocrine and autonomic changes, which in the short term return plasma volume to control levels and decrease total peripheral resistance and thus regulate blood pressure. The reduced sympathetic nerve activity has effects on arteriolar resistance, resulting in hyperperfusion of some tissues, which for specific tissues is time dependent. The increased central blood volume results in increased pulmonary artery pressure and a decline in vital capacity. The effect of increased hydrostatic pressure due to the depth of submersion does not affect stroke volume; however, a bradycardia results in decreased cardiac output, which is further reduced during breath holding. Hydrostatic compression, however, leads to elastic loading of the chest wall and negative pressure breathing. The depthdependent increased work of breathing leads to augmented respiratory muscle blood flow. The blood flow is increased to all lung zones with some improvement in the ventilation-perfusion relationship. The cardiac-renal responses are time dependent; however, the increased stroke volume and cardiac output are, during head-out immersion, sustained for at least hours. Changes in water temperature do not affect resting cardiac output; however, maximal cardiac output is reduced, as is peripheral blood flow, which results in reduced maximal exercise performance. In the cold, maximal cardiac output is reduced and skin and muscle are vasoconstricted, resulting in a further reduction in exercise capacity. respiratory; renal; immersion; exercise; aging; sex differences; submersion; pressure; energy cost THE UNDERWATER ENVIRONMENT is unique, and while it is a magical place with great history and beauty and plant and animal life and holds a wealth of resources, it also imposes pronounced physiological stresses on humans and animals. This brief review offers an overview of how the major environmental challenges, i.e., the pressure, temperature extremes, and the unbreathable ambient medium, of the "Silent World" affect circulation, renal system and water balance, breathing, exercise, and thermal balance and how it imposes some threats due to pharmacological or toxic effects of respired gases at high pressure, i.e., great depths. Adaptations to ...

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Section: Exercisementioning

confidence: 99%

The underwater environment: cardiopulmonary, thermal, and energetic demands

Pendergast¹,

Lundgren²

2009

Journal of Applied Physiology

133

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show abstract

“…It is usually accepted that drag-reducing suits can reduce skin friction, with an effect similar to shaving (Sharpe & Costill, 1998;Pendergast et al, 2006). Nevertheless, Mollendorf et al (2004) revealed that total drag decreased by 3 % to 10 % mostly due to decreased form drag in textile suits. These experimental data suggest that the water flow was tripped by frictional drag, remained attached to the swimmer body, thus decreasing form drag (Polidori et al, 2006;Marinho et al, 2009b).…”

Section: Equipmentsmentioning

confidence: 98%

Modelling Hydrodynamic Drag in Swimming using Computational Fluid Dynamics

Marinho¹,

Barbosa²,

Kjendlie³

et al. 2010

Computational Fluid Dynamics

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“…Aiming to achieve higher velocities, the swimmer should reduce the hydrodynamic drag force resisting forward motion and increase the propelling force. Regarding the first aim, several studies have analysed the effect of wearing different equipment on hydrodynamic drag, with special attention to the use of swimsuits (Toussaint et al 2002;Mollendorf et al 2004;Pendergast et al 2006). Recently, companies turned to covering the human skin with a technologically advanced fabric that aims to be an efficient performance enhancer.…”

Section: Introductionmentioning

confidence: 99%

“…Other authors suggested that the use of full body suits could reduce the total drag (pressure, wave and friction) (Toussaint et al 2002;Pendergast et al 2006). Friction drag seems to be largely influenced by the use of swimsuits; however, it represents only 10-15% of total drag (Mollendorf et al 2004;Bixler et al 2007). Added to that, these new swimsuits are very thigh fitting, thus compacting the body, eliminating air pockets (Mountjoy et al 2009) and improving the swimming coordination (Chollet et al 2010).…”

Section: Introductionmentioning

confidence: 99%