Effect of Fatigue on Stroking Characteristics in an Arms-Only 100-m Front-Crawl Race.

Nikoluski · September 27, 2006, 11:43am

APPLIED SCIENCES

Medicine & Science in Sports & Exercise. 38(9):1635-1642, September 2006.
Toussaint, Huub M. 1,2; Carol, Arnoud 2; Kranenborg, Hilke 2; Truijens, Martin J. 2
Abstract:
Purpose: Race analyses during swimming provide information on the time-dependent values of, among other variables, a swimmer’s clean swimming speed (v), stroke rate (SR), and stroke length (SL). The effect of fatigue on changes in v, SR, and SL was investigated.

Methods: Lap-averaged values of v, SR, and SL while swimming 100 m all out with arms only (trial 1) were related to the decline in mechanical power output measured during an all-out 100-m swim on the MAD system (trial 2), with legs immobilized in both trials.

Results: Swimming a 100-m front-crawl sprint using arms only led to a significant 24% decrease in lap-averaged mechanical power output (from 200 to 153 W, P < 0.01). This reduction in power-generating capacity led to a 12.4% decrease in v[spacing macron] when lap 1 was compared with lap 4 (from 1.69 to 1.48 m[middle dot]s-1, P < 0.01). SR declined throughout the race by 10.6% from 0.85 Hz (lap 1) to 0.76 Hz (lap 4, P < 0.05). Analysis revealed that this decrease in SR was linearly related to the decrease in v[spacing macron]. The reduction in SR reflected the reduced propulsive force required to overcome the v-dependent, and therefore lower, drag.

Conclusion: Decreases in swimming speed throughout a 100-m front-crawl race are the result of decreases in the power-producing capacity of the swimmer (fatigue). This fatigue-induced reduction in swimming speed will lead to a reduction in drag. The SR seems to be accommodated to this reduced power output capacity and concomitant diminished propulsion requirements.

Nikoluski · September 27, 2006, 11:45am

APPLIED SCIENCES

Medicine & Science in Sports & Exercise. 38(9):1643-1649, September 2006.
Trinity, Joel D. 1; Pahnke, Matthew D. 1; Reese, Edwin C. 2; Coyle, Edward F. 1,3
Abstract:
Introduction: Insight regarding the fluctuations in neuromuscular function among athletes during a taper is lacking.

Purpose: This study examined the time course of changes in maximal mechanical power (Pmax), torque at power maximum (T), velocity at power maximum (V), and swim performance (m[middle dot]s-1) that occur during the taper.

Methods: Using an arm ergometer with inertial loading, measurements were made during the week prior to the initiation of the taper (high volume, HV), during the 2- to 3-wk period of the taper (taper), and during the week of peak competition (peak) in 24 male competitive collegiate swimmers. Subjects were divided into groups that tapered to peak performance at either the conference (CONF, N = 13) or national (NAT, N = 11) championship competitions.

Results: CONF increased Pmax 10.2% (P < 0.01) and swim performance 4.4% (P < 0.001). NAT increased Pmax by 11.6% (P < 0.01), T by 7.4% (P < 0.02), and swim performance by 4.7% (P < 0.001). Pmax displayed a biphasic increase with approximately 50, 5, and 45% of the total increase occurring during the first, second, and third weeks of the taper, respectively. The biphasic response was the most common response among individual swimmers. Swimming performance was significantly correlated to both power and torque (P < 0.05).

Conclusion: In summary, maximal arm power measured using inertial load ergometry increased largely during the first and third weeks after training volume was tapered for peak performance in elite collegiate swimmers.