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 () 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, ) were either assigned to VL10 or TRF. In addition to rowing endurance training (about 75 min·d−1), 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 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, , 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%]). revealed no interaction effects (P = .55, , standard mean difference < .23) but large time effects (P < .05, ). Significant group × time interactions (P = .001, , 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.

No abstract

Each stretch-shortening-cycle (SSC) in elite sports (e.g. jumping, cycling), is characterised by utilising optimal movementparameters (e.g. muscle shortening velocity), for maximum power (jump height, cycle velocity). It is however unclear if relevant SSC movement-parameters in rowing, such as stroke rate and gearing, have to be maximised to obtain maximum power output or if an optimum relation emerges. Thus, we measured rowing-power (P row ), leg-power (P leg ) and work-perstroke (WPS) at of varying stroke rates (20-45 spm), gearings (lever-changes 0.87-0.90 m) and drag factors (100-180 Ws 3 /m 3 ) during rowing. Experienced sub-elite young athletes performed sprint-series on (single scull, n = 69, 20 ± 2 years, 186 ± 7 cm, 84 ± 9 kg) and off the water (rowing-ergometer, n = 30, 19 ± 3 years, 185 ± 11 cm, 77 ± 19 kg). P row increased with stroke rate for ergometer-test (r = 0.97, p < 0.001) and boat measurement (r = 0.98, p < 0.001) by 2.7%/ stroke and 4.4%/stroke, respectively. Interestingly, stroke rate had a high impact on WPS (r = 0.79, p < 0.001) during boat measurement, compared to no (or specifically no high) impact on WPS (r = −0.10, p = 0.166) during ergometermeasurements. Drag factor (ergometer: r = 0.83, p < 0.001) and gearing (boat: r = 0.60, p < 0.001) yielded moderate to high correlations to P row . These results indicate that no optimum stroke rate, gearing and drag factor exist for maximum power in rowing (sprint-measurement-range). Accordingly, the measurements yielded maximum power for maximum stroke rate, gearing, and drag factor.

The present study examined the effects of a functional high-intensity suspension training (FunctionalHIIT) on resting blood pressure, psychological well-being as well as on upper body and core strength and cardiorespiratory fitness in moderately trained participants. Twenty healthy, moderately trained adults (10 males and 10 females; age: 36.2 ± 11.1 years, BMI: 23.9 ± 3.7) were randomly assigned to a FunctionalHIIT training group or passive control group (CON). FunctionalHIIT performed 16 sessions (2× week for eight weeks, 30 min per session), whereas CON maintained their habitual lifestyle using a physical activity log. Before and after FunctionalHIIT intervention, resting blood pressure and quality of life (short version of the WHO Quality of Life questionnaire (WHOQOL-BREF)) were assessed. Furthermore, maximum-repetition (leg press, chest press, pulldown, back extension) and trunk muscle strength (Bourban test) as well as cardiorespiratory fitness (Vameval test), were measured before and after the intervention. Both systolic and diastolic blood pressure and WHOQOL-BREF did not change significantly but both showed moderate training-induced effects (0.62 < standardized mean difference (SMD) < 0.82). Significant improvements in the FunctionalHIIT group were evident on leg press (p < 0.01), chest press (p < 0.05), and left side Bourban test (p < 0.05). Cardiorespiratory fitness did not reveal any time effects or time × group interactions. The present study revealed that eight weeks of FunctionalHIIT represents a potent stimulus to improve health-related parameters in young adults, whereas FunctionalHIIT was not sufficient to improve cardiorespiratory fitness.

The resulting muscular performance is considered notably higher during a stretch shortening cycle (SSC) compared to an isolated concentric contraction. Thus, the present study examined the occurrence and magnitude of rowing performance enhancement after a flexion-extension cycle (FEC) of the legs compared to both concentric contractions only and isometric pre-contraction. Therefore, 31 sub-elite male rowers (age: 25 ± 6 years, height: 1.90 ± 0.02 m, weight: 91 ± 10 kg, weekly training volume: 11.4 ± 5.3 h/week, rowing experience: 7.1 ± 2.7 years) randomly completed (a) isolated concentric rowing strokes (DRIVE), (b) single FEC-type rowing strokes (SLIDE-DRIVE), and (c) rowing strokes with an isometric pre-contraction (ISO-DRIVE). The resulting rowing power (P row), leg power (P leg), and work per stroke (WPS) were recorded using motion-capturing, force, and rotation sensors. Comparison of DRIVE and SLIDE-DRIVE revealed significantly (p < 0.05) higher P row (+11.8 ± 14.0%), P leg (+19.6 ± 26.7%), and WPS (+9.9 ± 10.5%) during SLIDE-DRIVE. Compared to ISO-DRIVE, P leg (+9.8 ± 26.6%) and WPS (+6.1 ± 6.7%) are again significantly (p < 0.05) higher for SLIDE-DRIVE. In conclusion, notably higher work and power outputs (compared to an isolated concentric contraction) during FEC rowing referred to an underlying SSC. Future ultrasound studies should elucidate whether a real SSC on the muscle tendon unit level account for these performance enhancements.

No abstract

Running power as measured by foot-worn sensors is considered to be associated with the metabolic cost of running. In this study, we show that running economy needs to be taken into account when deriving metabolic cost from accelerometer data. We administered an experiment in which 32 experienced participants (age = 28 ± 7 years, weekly running distance = 51 ± 24 km) ran at a constant speed with modified spatiotemporal gait characteristics (stride length, ground contact time, use of arms). We recorded both their metabolic costs of transportation, as well as running power, as measured by a Stryd sensor. Purposely varying the running style impacts the running economy and leads to significant differences in the metabolic cost of running (p < 0.01). At the same time, the expected rise in running power does not follow this change, and there is a significant difference in the relation between metabolic cost and power (p < 0.001). These results stand in contrast to the previously reported link between metabolic and mechanical running characteristics estimated by foot-worn sensors. This casts doubt on the feasibility of measuring running power in the field, as well as using it as a training signal.

The consideration of the temporal and electromyographic (EMG) characteristics of stretch-shortening cycles (SSC) are crucial for the conceptualization of discipline-specific testing and training. Since leg muscles are first stretched (eccentric) and then contracted (concentric) during rowing, it can be assumed that the entire muscle tendon complex performs a SSC. Thus, it should be elucidated whether the rowing cycle can be attributed to either a slow or fast SSC. Therefore, EMG of the vastus medialis and gastrocnemius were captured (n = 10, 22.8 ± 3.1 years, 190 ± 6 cm, 82.1 ± 9.8 kg) during (single scull) rowing and subsequently compared to typical slow (countermovement jump, CMJ) and fast (drop jump, DJ) SSCs. The elapsed time between the EMG onset and the start of the eccentric phase was monitored. The pre-activation phase (PRE, before the start of the eccentric phase) and the reflex-induced activation phase (RIA 30–120 ms after the start of the eccentric phase) have been classified. Notable muscular activity was observed during DJ before the start of the eccentric phase (PRE) as well as during RIA. In contrast, neither CMJ nor rowing revealed any EMG-activity in these two phases. Interestingly, CMJ and race-specific rowing showed an EMG-onset during the eccentric phase. We conclude that rowing is more attributable to a slow SSC and implies that fast SSC does not reflect discipline specific muscle action and could hamper rowing-performance-enhancement.