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  • Author: Jürgen M. Steinacker x
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Michael Kellmann, Dieter Altenburg, Werner Lormes, and Jürgen M. Steinacker

Training stress and adequate recovery have been identified as important factors to enhance performance in sports and to avoid overtraining. Research dealing with training monitoring and overtraining is mostly based on the Profile of Mood Stales (POMS). Recently, Kellmann and Kallus (2000, 2001) published the Recovery-Stress-Questionnaire for Athletes (RESTQ-Sport), which assesses training effects from the perspective of stress and recovery. During a six-week training camp before and at the World Championships, 24 female and 30 male rowers of the German Junior National Rowing Team completed the RESTQ-Sport and the POMS six times. Results of selected MANOVA’s revealed significant increases of stress and decreases of recovery when training load expands, and vice versa. Changes in mood, creatine kinase, and ergometer performance reflect the alteration and success of training. These results suggest that the RESTQ-Sport is a potential alternative to the POMS in evaluating the impact of various training schedules.

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Gunnar Treff, Kay Winkert, Katja Machus, and Jürgen M. Steinacker

Purpose: Ramp tests are continuously increasing exercise tests used for the determination of maximal oxygen uptake (V˙O2max), which is identifiable by a plateau in oxygen uptake despite increasing mechanical power output (LOAD). On wind-braked rowing ergometers (RowErg), it is hardly feasible to ensure a continuous increase in LOAD until test termination, as neither resistance nor stroke frequency is externally adjustable but depends on the rower. To enable ramp tests on RowErg, the authors produced visual stroke-by-stroke feedback showing target and actual LOAD to the rower. The software supports automatic test termination (TERMauto) if LOAD ceases to increase. The authors aimed to evaluate linearity of the LOAD increment and calculate the difference between TERMauto and test duration at subjective exhaustion. Materials: Twenty-eight highly trained male rowers performed a ramp test until subjective exhaustion on RowErg, targeting an increment of 35 W·min−1. LOAD was measured as work per time via external force and position sensors and visualized on a computer screen. TERMauto was deactivated, but all data were logged. Test duration at subjective exhaustion was subsequently compared with virtual test duration at TERMauto calculated from the log files. Results: Regression between time and LOAD was y = 167 + 34.6 W (r = .99). Individual correlations ranged from .97 to 1.0. TERMauto caused 12- to 35-s-shorter test durations than subjective exhaustion in 4 rowers, leading to an underestimation in V˙O2max not higher than 1.2% or 3.7%. Conclusion: This setup allows one to perform ramp tests on RowErg with continuously increasing LOAD until TERMauto. In particular cases V˙O2max might be slightly underestimated at TERMauto.

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Susanne Kobel, Sarah Kettner, Nanette Erkelenz, Dorothea Kesztyüs, and Jürgen M. Steinacker

Physical Education (PE) can foster regular physical activity (PA) in children. However, children engage in insufficient moderate to vigorous PA (MVPA) during PE. This study objectively investigated MVPA of children during a single, compared with double PE-period. In 294 children (7.1 ± 0.7 years) PA was objectively assessed. PE periods were determined and PA was individually calculated. Children spent 8.5 ± 7.3 minutes of each 45 minutes PE lesson in MVPA. Boys were significantly more active than girls (p ≤ .01). All children participated in 135 minutes PE/week, 32.7% were scheduled one double and one single PE-period. Children, with a double PE-period and one single lesson engaged in significantly less MVPA than children, who had three single periods of PE (6.7 ± 6.9 minutes/45 minutes vs. 9.4 ± 7.4 minutes/45 minutes, respectively; p ≤ .01) In conclusion, single periods of PE seem to be more effective in getting primary school children to engage in more MVPA than one double period per week.

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Kay Winkert, Johannes Kirsten, Rupert Kamnig, Jürgen M. Steinacker, and Gunnar Treff

Purpose: Automated metabolic analyzers are frequently utilized to measure maximal oxygen consumption (V˙O2max). However, in portable devices, the results may be influenced by the analyzer’s technological approach, being either breath-by-breath (BBB) or dynamic micro mixing chamber mode (DMC). The portable metabolic analyzer K5 (COSMED, Rome, Italy) provides both technologies within one device, and the authors aimed to evaluate differences in V˙O2max between modes in endurance athletes. Methods: Sixteen trained male participants performed an incremental test to voluntary exhaustion on a cycle ergometer, while ventilation and gas exchange were measured by 2 structurally identical COSMED K5 metabolic analyzers synchronously, one operating in BBB and the other in DMC mode. Except for the flow signal, which was measured by 1 sensor and transmitted to both devices, the devices operated independently. V˙O2max was defined as the highest 30-second average. Results: V˙O2max and V˙CO2@V˙O2max were significantly lower in BBB compared with DMC mode (−4.44% and −2.71%), with effect sizes being large to moderate (ES, Cohen d = 0.82 and 1.87). Small differences were obtained for respiratory frequency (0.94%, ES = 0.36), minute ventilation (0.29%, ES = 0.20), and respiratory exchange ratio (1.74%, ES = 0.57). Conclusion: V˙O2max was substantially lower in BBB than in DMC mode. Considering previous studies that also indicated lower V˙O2 values in BBB at high intensities and a superior validity of the K5 in DMC mode, the authors conclude that the DMC mode should be selected to measure V˙O2max in athletes.