Komei Ikuta

Determination and validity of critical velocity as an index of swimming performance in the competitive swimmer

SummaryThe purpose of this investigation was to test whether the concept of critical power used in previous studies could be applied to the field of competitive swimming as critical swimming velocity (νcrit). The νcrit, defined as the swimming velocity over a very long period of time without exhaustion, was expressed as the slope of a straight line between swimming distance (dlim) at each speed (with six predetermined speeds) and the duration (tlim). Nine trained college swimmers underwent tests in a swimming flume to measure νcrit at those velocities until the onset of fatigue. A regression analysis ofdlim on trim calculated for each swimmer showed linear relationships (r2>0.998,P<0.01), and the slope coefficient signifying νcrit ranged from 1.062 to 1.262 m · s−1 with a mean of 1.166 (SD 0.052) m · s−1. Maximal oxygen consumption (

Cardiovascular responses induced during high-intensity eccentric and concentric isokinetic muscle contraction in healthy young adults.

\dot VO_{2\max }

Relationship between plasma endothelin-1 concentration and cardiovascular responses during high-intensity eccentric and concentric exercise.

), oxygen consumption (

The heart rate increase at the onset of high-work intensity exercise is accelerated by central blood volume loading.

\dot VO_2

Differences of muscle oxygenation during eccentric and concentric contraction

) at anaerobic threshold, and the swimming also velocity at the onset of blood lactate accumulation (νOBLA) were also determined during the incremental swimming test. The νcrit showed significant positive correlations with