Consistency of Pacing and Metabolic Responses During 2000-m Rowing Ergometry

Purpose:This study investigated the pacing strategy adopted and the consistency of performance and related physiological parameters across three 2000-m rowing-ergometer tests.Methods:Fourteen male well-trained rowers took part in the study. Each participant performed three 2000-m rowing-ergometer tests interspersed by 3–7 d. Throughout the trials, respiratory exchange and heart rate were recorded and power output and stroke rate were analyzed over each 500 m of the test. At the completion of the trial, assessments of blood lactate and rating of perceived exertion were measured.Results:Ergometer performance was unchanged across the 3 trials; however, pacing strategy changed from trial 1, which featured a higher starting power output and more progressive decrease in power, to trials 2 and 3, which were characterized by a more conservative start and an end spurt with increased power output during the final 500 m. Mean typical error (TE; %) across the three 2000-m trials was 2.4%, and variability was low to moderate for all assessed physiological variables (TE range = 1.4−5.1%) with the exception of peak lactate (TE = 11.5%).Conclusions:Performance and physiological responses during 2000-m rowing ergometry were found to be consistent over 3 trials. The variations observed in pacing strategy between trial 1 and trials 2 and 3 suggest that a habituation trial is required before an intervention study and that participants move from a positive to a reverse-J-shaped strategy, which may partly explain conflicting reports in the pacing strategy exhibited during 2000-m rowing-ergometer trials.

Reindeer (Rangifer tarandus) response to feces and urine from sheep (Ovis aries) and reindeer

<p>In many Norwegian alpine and tundra areas sheep and reindeer graze sympatrically. Areas covered with dung or urine may have consequences for reindeer pasture utilization. Experiments were conducted on 5 stall fed male reindeer calves where animals were individually presenred with two troughs (experimental and control) containing 200 g of concentrate. Fresh and dry sheep and reindeer pellets (50 g wet weight) were mixed with the concentrate in the experimental trough and the aversive response was tested against the control. Both fresh sheep (P &lt; 0.0001) and reindeer (P &lt; 0.0001) pellets were associated with aversive response by reindeer. A similar response was found for dry sheep (P = 0.006) and dry reindeer (P = 0.0009) pellets. Similar trials were conducted using sheep and reindeer urine (20 g sprayed evenly on the food) and the aversive response by reindeer was tested against the control (sprayed with 20 g of water). Both sheep and reindeer urine stimulated an aversive response by reindeer {P = 0.03 for both tests). The differences in the aversive response of reindeer ro fresh sheep and reindeer pellets, dry sheep and reindeer pellets and sheep and reindeer urine were also tested. No differences by reindeer were found between sheep and reindeer pellets, either for fresh (P = 0.28) or dry (P = 0.07), or between food treated with sheep and reindeer urine (P = 0.28). Possible habituation to sheep and reindeer pellets was tested using 8 consecutive trials with dry pellets, followed by 2 additional trials when dry pellets were soaked in water. This was done to simulate natural dry periods followed by rain showers. Habituation effects were found in trials with dry sheep and reindeer pellets. Subsequent trials with fecal pellets soaked in water significantly reduced food intake when compared with the last habituation trial with dry pellets (P &lt; 0.05).</p>

Anxiety as Avoidance: Defensive Information Processing as Measured by Decreased Information Intake in Habituation to a Tone

High and low anxious men and women were tested for habituation to a tone. Mean first habituation trial, of low-amplitude electro-dermal responding, occurred significantly sooner for subjects high in anxiety than for those low in anxiety. Analysis indicates defensive information processing occurs under anxiety.