Search Results

You are looking at 1 - 5 of 5 items for

  • Author: Lars Donath x
  • All content x
Clear All Modify Search
Restricted access

Lars Donath and Peter Wolf

Multiaxial force sensors were applied to measure interaction forces during dynamic movements, such as climbing. When interaction forces are interpreted, minimal detectable changes, typical errors, and coefficients of variation of related performance metrics should be quantified. Thus, the presented study evaluated absolute and relative between-trial reliability with and without previous familiarization trials. Eleven Swiss elite climbers (5 females, 6 males) were tested during 2 repetitive climbing sequences (including 4 instrumented holds: 2 crimps, 1 undercling, 1 sloper). To ensure comparable relative intensity, females climbed at 20°, 25°, 30°, 25°, and 20° wall inclination, while males climbed at 25°, 30°, 35°, 30°, and 25°. Contact time, maximal resultant force, mean resultant force, impulse, and the number of load changes were analyzed at the lowest inclination. Acceptable to good between-trial reliability was found for nearly all holds and performance metrics. Performance analyses after 5 minutes of familiarization on the unknown boulder, which equals up to 3 trials, yielded to higher variability compared with performance analyses after several familiarization trials. Accordingly, the majority of absolute and relative reliability data improved after familiarization trails. Thus, to be detectable, interventional changes have to exceed higher biological variability during on-sight conditions than during red-point conditions.

Restricted access

Ralf Roth, Lars Donath, Lukas Zahner, and Oliver Faude

For performance and injury prevention in sport, core strength and endurance are focused prerequisites. Therefore we evaluated characteristics of trunk muscle activation and performance during strength-endurance related trunk field tests. Strength-endurance ability, as total time to failure, and activation of trunk muscles was measured in 39 football players of the highest German female football league (Bundesliga) (N = 18, age: 20.7 y [SD 4.4]) and the highest national male under-19 league (N = 21, age: 17.9 y [0.7]) in prone plank, side plank, and dorsal position. Maximal isometric force was assessed during trunk extension and flexion, rotation, and lateral flexion to normalize EMG and to compare with the results of strength-endurance tests. For all positions of endurance strength tests, a continuous increase in normalized EMG activation was observed (P < .001). Muscle activation of the rectus abdominis and external oblique in prone plank position exceeded the maximal voluntary isometric contraction activation, with a significantly higher activation in females (P = .02). We conclude, that in the applied strength-endurance testing, the activation of trunk muscles was high, especially in females. As high trunk muscle activation can infer fatigue, limb strength can limit performance in prone and side plank position, particularly during high trunk muscle activation.

Restricted access

Steffen Held, Anne Hecksteden, Tim Meyer, and Lars Donath

Purpose: The present intervention study examined the effects of intensity-matched velocity-based strength training with a 10% velocity loss (VL10) versus traditional 1-repetition maximum (1RM) based resistance training to failure (TRF) on 1RM and maximal oxygen uptake (V˙O2max) in a concurrent training setting. Methods: Using the minimization method, 21 highly trained rowers (4 females and 17 males; 19.6 [2.1] y, 1.83 [0.07] m, 74.6 [8.8] kg, V˙O2max:64.9[8.5]mL·kg1·min1) were either assigned to VL10 or TRF. In addition to rowing endurance training (about 75 min·d1), both groups performed strength training (5 exercises, 80% 1RM, 4 sets, 2–3 min interset recovery, 2 times/week) over 8 weeks. Squat, deadlift, bench row, and bench press 1RM and V˙O2max rowing-ergometer ramp tests were completed. Overall recovery and overall stress were monitored every evening using the Short Recovery and Stress Scale. Results: Large and significant group × time interactions (P < .03, ηp2>.23, standard mean differences [SMD] > 0.65) in favor of VL10 (averaged +18.0% [11.3%]) were observed for squat, bench row, and bench press 1RM compared with TRF (averaged +8.0% [2.9%]). V˙O2max revealed no interaction effects (P = .55, ηp2=.01, standard mean difference < .23) but large time effects (P < .05, ηp2>.27). Significant group × time interactions (P = .001, ηp2>.54, SMD > |0.525|) in favor of VL10 were also observed for overall recovery and overall stress 24 and 48 hours after strength training. Conclusions: VL10 serves as a promising means to improve strength capacity at lower repetitions and stress levels in highly trained athletes. Future research should investigate the interference effects of VL10 in strength endurance sports and its effects when increasing weekly VL10 sessions within one macrocycle.

Restricted access

Lars Donath, Oliver Faude, Stephanie A. Bridenbaugh, Ralf Roth, Martin Soltermann, Reto W. Kressig, and Lukas Zahner

This study examined transfer effects of fall training on fear of falling (Falls Efficacy Scale—International [FES–I]), balance performance, and spatiotemporal gait characteristics in older adults. Eighteen community-dwelling older adults (ages 65–85) were randomly assigned to an intervention or control group. The intervention group completed 12 training sessions (60 min, 6 weeks). During pre- and posttesting, we measured FES–I, balance performance (double limb, closed eyes; single limb, open eyes; double limb, open eyes with motor-interfered task), and gait parameters (e.g., velocity; cadence; stride time, stride width, and stride length; variability of stride time and stride length) under single- and motor-interfered tasks. Dual tasks were applied to appraise improvements of cognitive processing during balance and gait. FES–I (p = .33) and postural sway did not significantly change (0.36 < p < .79). Trends toward significant interaction effects were found for step width during normal walking and stride length variability during the motor dual task (p = .05, ηp 2 = .22). Fall training did not sufficiently improve fear of falling, balance, or gait performance under single- or dual-task conditions in healthy older adults.

Restricted access

Lars Donath, Lukas Zahner, Mareike Cordes, Henner Hanssen, Arno Schmidt-Trucksäss, and Oliver Faude

The study investigated physiological responses during 2-km walking at a certain intensity of a previously performed maximal exercise test where moderate perceived exertion was reported. Twenty seniors were examined by an incremental walking treadmill test to obtain maximal oxygen uptake (VO2max). A submaximal 2-km walking test was applied 1 wk later. The corresponding moderate perceived exertion (4 on the CR-10 scale) during the VO2max test was applied to the 2-km treadmill test. Moderate exertion (mean rating of perceived exertion [RPE]: 4 ± 1) led to 76% ± 8% of VO2max and 79% ± 6% of maximal heart rate. RPE values drifted with a significant time effect (p = .001, ηp = .58) during the 2-km test from 3 ± 0.7 to 4.6 ± 0.8. Total energy expenditure (EE) was 3.3 ± 0.5 kcal/kg. No gender differences in ventilatory, heart-rate, or EE data occurred. Brisk walking at moderate RPE of 3–5 would lead to a beneficial physiological response during endurance training and a weekly EE of nearly 1,200 kcal when exercising 5 times/wk for 30 min.