Search results for "maximum"
showing 10 items of 753 documents
Corticospinal and intracortical excitability is modulated in the knee extensors after acute strength training.
2021
The corticospinal responses to high-intensity and low-intensity strength-training of the upper limb are modulated in an intensity-dependent manner. Whether an intensity-dependent threshold occurs following acute strength training of the knee extensors (KE) remains unclear. We assessed the corticospinal responses following high-intensity (85% of maximal strength) or low-intensity (30% of maximal strength) KE strength-training with measures taken during an isometric KE task at baseline, post-5, 30 and 60-min. Twenty-eight volunteers (23 ± 3 years) were randomized to high-intensity (n = 11), low-intensity (n = 10) or to a control group (n = 7). Corticospinal responses were evoked with transcra…
Aging and strength training influence knee extensor intermuscular coherence during low- and high-force isometric contractions
2019
Aging is associated with reduced maximum force production and force steadiness during low-force tasks, but both can be improved by training. Intermuscular coherence measures coupling between two peripheral surface electromyography (EMG) signals in the frequency domain. It is thought to represent the presence of common input to alpha-motoneurons, but the functional meaning of intermuscular coherence, particularly regarding aging and training, remain unclear. This study investigated knee extensor intermuscular coherence in previously sedentary young (18–30 years) and older (67–73 years) subjects before and after a 14-week strength training intervention. YOUNG and OLDER groups performed maximu…
Effects of combined endurance and strength training on muscle strength, power and hypertrophy in 40-67-year-old men
2009
Both strength and endurance training have several positive effects on aging muscle and physical performance of middle-aged and older adults, but their combination may compromise optimal adaptation. This study examined the possible interference of combined strength and endurance training on neuromuscular performance and skeletal muscle hypertrophy in previously untrained 40-67-year-old men. Maximal strength and muscle activation in the upper and lower extremities, maximal concentric power, aerobic capacity and muscle fiber size and distribution in the vastus lateralis muscle were measured before and after a 21-week training period. Ninety-six men [mean age 56 (SD 7) years] completed high-int…
Normalwerterstellung von Blutströmungsgeschwindigkeiten an der Arteria mesenterica superior bei Früh- und Reifgeborenen mit der Duplexsonographie
1994
In a prospective study blood flow velocity measurements were performed in 110 "healthy" newborn with duplex Doppler sonography in the superior mesenteric artery to obtain standard values. In 49 of these neonates 15, 30, and 45 minutes following feeding examinations were performed. Peak systolic flow velocity, end systolic flow velocity, time average flow velocity and time average maximum flow velocity were determined, the resistance and Pourcelot index as well as the volume blood flow were calculated. The children's gestational age was 27-42 weeks, the postnatal age was 2-68 days and the body weight was 920-4190 g. All measured blood flow velocities showed a synchronous relation to feeding …
Microvascular blood flow changes of the abductor pollicis brevi muscle during sustained static exercise
2020
ABSTRACTA practical assessment of the health of the palm muscle, abductor pollicis brevis (APB), is important for diagnosis of different conditions. Here we have developed a protocol and a probe to utilize diffuse correlation spectroscopy (DCS) to characterize microvascular blood flow changes in the APB during and after sustained isometric exercise, during and after thumb abduction at at 55% of maximum voluntary contraction (MVC). Blood flow in the APB decreased during exercise in the subjects (n=13) with high MVC (n=7) and stayed constant in the ones with low MVC (n=6) suggesting that the mechanical occlusion due to increased intramuscular pressure exceeded the vasodilation elicited by the…
Kryotherapie primärer und sekundärer Lebertumoren
2002
AIMS We assessed the morbidity, mortality and efficacy of cryotherapy for primary and secondary malignant liver tumours in a prospective case control study. METHODS Since 1996 we performed 77 cryosurgical procedures on 71 patients. 6 patients had hepatocellular carcinoma, the remainders metastases, mainly of colorectal origin (n = 49). Cryotherapy was used when a complete tumour resection was not feasible, but complete tumour destruction by cryotherapy seemed possible. Mean follow-up was 21 months. RESULTS The mean number of lesions per patient was 2.6 (1-10) with a mean maximum diameter of 3.7 cm (1-11). In 36 of 71 patients cryotherapy was used in combination with liver resection. Morbidi…
Strength and power changes of the human plantar flexors and knee extensors in response to resistance training in old age
2002
Aim: The aim of the present study was to assess and compare the improvements of muscle strength and power induced by a 16-week resistive programme in a population of 16 older men aged 65-81 years. Methods: Training was performed three times per week at an intensity of 80% of one repetition maximum (1RM) and consisted of both calf raise and leg press exercises. Before-, during- and after-training, maximum isometric and isokinetic torques, maximum power, 1RM, muscle cross-sectional area (CSA) and electromyographic activity (EMG) of the plantar flexors (PF) and knee extensors (KE) were examined. Results: For the KE and PF, respectively, training resulted in a 29.9 ± 4.4% (mean ± SE) and 21.6 ±…
Changes in electromyographic activity, muscle fibre and force production characteristics during heavy resistance/power strength training in middle-ag…
2001
The effects of a 6-month resistance training (2 day/week) designed to develop both strength and power on neural activation by electromyographic activity (EMG) of the agonist and antagonist knee extensors, muscle fibre proportion and areas of type I, IIa, and IIb of the vastus lateralis (VL) as well as maximal concentric one repetition maximum (1 RM) strength and maximal and explosive isometric strength of the knee extensors were examined. A total of 10 middle-aged men (M40; 42 +/- 2), 11 middle-aged women (W40; 39 +/- 3), 11 elderly men (M70; 72 +/- 3) and 10 elderly women (W70; 67 +/- 3) served as subjects. Maximal and explosive strength values remained unaltered during a 1-month control p…
CT-Angiographie bei arterieller Verschlußkrankheit: Vergleich von 3 Rekonstruktionsverfahren
1997
Purpose To evaluate different rendering techniques of CT data for the assessment of long vessel segments in peripheral vascular occlusive disease. Material and methods 40 CT angiograms (aortoiliac: n = 20, leg arteries: n = 20) were viewed using three different rendering techniques: 1, maximum intensity projection (MIP); 2, volume rendering (VR); 3, shaded surface display (SSD). CT angiograms were obtained in 6 or 8 projections. Axial cross-section images were analysed using an interactive cine mode. Intraarterial DSA was the standard in all cases. Results The sensitivities for the diagnosis of occlusive disease were 100% (cross-section images), 94% (MIP), 91% (VR) and 93% (SSD). The specif…
Maximum Dynamic Lower-Limb Strength Was Maintained During 24-Week Reduced Training Frequency in Previously Sedentary Older Women.
2018
Walker, S, Serrano, J, and Van Roie, E. Maximum dynamic lower-limb strength was maintained during 24-week reduced training frequency in previously sedentary older women. J Strength Cond Res 32(4): 1063-1071, 2018-There is little study into the effects of reducing strength training below the recommended twice weekly frequency, particularly in older women, despite the possibility that individuals will encounter periods of reduced training frequency. The purpose of the present study was to determine the effects of a period of reduced training frequency on maximum strength and muscle mass of the lower limbs in comparison with the recommended training frequency of twice per week. After an initia…