Search results for "Lifting"
showing 10 items of 111 documents
One repetition maximum bench press performance: A new approach for its evaluation in inexperienced males and females: A pilot study
2014
Summary The aim of this study was to evaluate a new method to perform the one repetition maximum (1RM) bench press test, by combining previously validated predictive and practical procedures. Eight young male and 7 females participants, with no previous experience of resistance training, performed a first set of repetitions to fatigue (RTF) with a workload corresponding to 1/3 of their body mass (BM) for a maximum of 25 repetitions. Following a 5-min recovery period, a second set of RTF was performed with a workload corresponding to 1/2 of participants’ BM. The number of repetitions performed in this set was then used to predict the workload to be used for the 1RM bench press test using May…
Hilbert space operators with two-isometric dilations
2021
A bounded linear Hilbert space operator $S$ is said to be a $2$-isometry if the operator $S$ and its adjoint $S^*$ satisfy the relation $S^{*2}S^{2} - 2 S^{*}S + I = 0$. In this paper, we study Hilbert space operators having liftings or dilations to $2$-isometries. The adjoint of an operator which admits such liftings is characterized as the restriction of a backward shift on a Hilbert space of vector-valued analytic functions. These results are applied to concave operators (i.e., operators $S$ such that $S^{*2}S^{2} - 2 S^{*}S + I \le 0$) and to operators similar to contractions or isometries. Two types of liftings to $2$-isometries, as well as the extensions induced by them, are construct…
Acute hormonal responses to heavy resistance exercise in younger and older men
1998
The purpose of this investigation was to examine the acute responses of several hormones [total and free testosterone (TT and FT, respectively), adrenocorticotropic hormone (ACTH), cortisol (C), growth hormone (GH), and insulin (INS)] to a single bout of heavy resistance exercise (HRE). Eight younger [30-year (30y) group] and nine older [62-year (62y) group] men matched for general physical characteristics and activity levels performed four sets of ten repetitions maximum (RM) squats with 90 s rest between sets. Blood samples were obtained from each subject via an indwelling cannula with a saline lock pre-exercise, immediately post-exercise (IP), and 5, 15 and 30 min post-exercise. Levels o…
Caffeine Increases Strength and Power Performance in Resistance-trained Females During Early Follicular Phase
2020
The effects of 4 mg·kg−1caffeine ingestion on strength and power were investigated for the first time, in resistance-trained females during the early follicular phase utilizing a randomized, double-blind, placebo-controlled, crossover design. Fifteen females (29.8 ± 4.0 years, 63.8 ± 5.5 kg [mean ± SD]) ingested caffeine or placebo 60 minutes before completing a test battery separated by 72 hours. One-repetition maximum (1RM), repetitions to failure (RTF) at 60% of 1RM, was assessed in the squat and bench press. Maximal voluntary contraction torque (MVC) and rate of force development (RFD) were measured during isometric knee extensions, while utilizing interpolated twitch technique to measu…
Age-related variation in mobility independence among wheelchair users with spinal cord injury: A cross-sectional study
2016
To evaluate age-related variation in mobility independence among community-living wheelchair users with spinal cord injury (SCI).Community Survey (2011-2013) as part of the Swiss Spinal Cord Injury Cohort Study.Community.Individuals aged 16 years or older with traumatic or non-traumatic SCI permanently residing in Switzerland and using a wheelchair for moving around moderate distances (10-100 m).Not applicable.Mobility-related items of the Spinal Cord Independence Measure-Self Report were matched to the three principal domains "changing basic body position," "transferring oneself" and "moving around." Binary outcomes ("independence" vs. "no independence") were created for every domain and a…
Basal concentrations and acute responses of serum hormones andstrength development during heavy resistance training in middle-aged andelderly men and…
2000
Effects of 6 months of heavy resistance training combined with explosive exercises on both basal concentrations and acute responses of total and free testosterone, growth hormone (GH), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), cortisol and sex hormone-binding globulin (SHBG), as well as voluntary neural activation and maximal strength of knee extensors were examined in 10 middle-aged men (M40; 42 +/- 2 years), 11 middle-aged women (W40; 39 +/- 3 years), 11 elderly men (M70; 72 +/- 3 years), and in 10 elderly women (W70; 67 +/- 3 years). The maximal integrated electromyographic (iEMG) and 1 repetition maximum (RM) knee-extension values remained unaltered in all g…
Acute Hormonal Responses to Heavy Resistance Exercise in Men and Women at Different Ages
1995
To examine acute endogenous hormonal responses to heavy resistance exercise eight young women (YW) and eight young men (YM) in the 30-year age group, seven middle-aged women (MW) and eight middle-aged men (MM) in the 50-year age group as well as eight elderly women (EW) and eight elderly men (EM) in the 70-year age group performed a heavy resistance exercise session with three different exercises (bench press, sit-up exercise and bilateral leg press). The relative loading intensity and volume of the exercise session were kept the same for each subject so that they performed each of the 5 sets of each exercise with the maximal load possible for 10 repetitions per set (10 repetition maximum).…
Effects of movement direction upon kinematic characteristics of vertical arm pointing movements in man
1998
Vertical arm pointing movements in two directions (upwards and downwards), imposing two different loads (unload and 0.5 kg) and speeds (normal and fast) have been studied in six subjects. Movements were recorded using an optoelectronic system. Data analysis concentrated upon finger-tip kinematics. Significant effects of movement direction were recorded upon velocity profiles. The acceleration time, computed relative to total movement time, was greater for downward movements than for upward movements. In contrast however, no effects of load or speed were observed. Movement time was not affected by movement direction or load, for both speeds tested. These results suggest different planning pr…
Effects of kinematics constraints on hand trajectory during whole-body lifting tasks
2000
Trajectories of the hands and whole-body center of mass were studied during whole-body lifting tasks. The movements of different parts of the body were monitored with the ELITE system. Subjects were instructed to lift to shoulder height an object placed at one of two distances (5-45 cm) before them on the floor. The lifts were performed both with and without kinematics constraints (i.e. to produce a straight hand trajectory while lifting, and to lift without any instructions, respectively). Hand trajectories were roughly straight when performed under the constrained condition, but curved when performed without instruction. Hand velocity curves showed bell-shaped profiles. In both groups, bo…
Diagnosing fatigue in gait patterns by support vector machines and self-organizing maps
2009
The aim of the study was to train and test support vector machines (SVM) and self-organizing maps (SOM) to correctly classify gait patterns before, during and after complete leg exhaustion by isokinetic leg exercises. Ground reaction forces were derived for 18 gait cycles on 9 adult participants. Immediately before the trials 7-12, participants were required to completely exhaust their calves with the aid of additional weights (44.4±8.8kg). Data were analyzed using: (a) the time courses directly and (b) only the deviations from each individual's calculated average gait pattern. On an inter-individual level the person recognition of the gait patterns was 100% realizable. Fatigue recognition …