Search results for "Isometric exercise"

2020

Background: An adequate level of muscular fitness is related to occupational performance in military personnel, including pilots flying high performance aircraft. The aim of this study was to describe the baseline level and the change in muscular fitness between the first and the second years of the Air Force Academy among fighter pilot cadets. Methods: The muscular strength and endurance test results of 182 male fighter pilot cadets were analyzed during their first year in the Air Force Academy and one year after. Maximal isometric strength tests included trunk flexion, trunk extension and bilateral leg extension tests, whereas muscle endurance was measured with modified a sit-up test and …

Neuromuscular and mobility responses to a vibration session in hypoxia in multiple sclerosis

2020

AbstractThe aim of this study was to investigate the acute effects of vibration training (WBVT) under hypoxic and normoxic conditions on the voluntary rate of force development (RFD), balance and muscle oxygen saturation (SMO2) in persons with Multiple Sclerosis (MS). 10 participants completed the study (30% males, 44.4±7.7 years, 164.3±8.9 cm, 65.2±11.1 kg, 2.5±1.3 Expanded Disability Status Scale, 24.1±4.0 kg.m−2 BMI). Maximal force, RFD during isometric knee extension, static balance with eyes open and closed and sit-to-stand test were evaluated before and immediately after one session of WBVT (12 60-s bout of vibration; frequency 35 Hz; amplitude 4 mm; 1-min rest intervals) under both n…

Muscle cross-sectional area, force production and relaxation characteristics in women at different ages

1991

Thirty women, divided among three different age groups, i.e. 30 years (range 26–35;n = 10), 50 years (range 46–55;n = 10) and 70 years (range 66–75;n = 10) volunteered as subjects for examination of the characteristics of the muscle cross-sectional area (CSA), maximal voluntary isometric force, isometric force-time and relaxation-time of their leg extensor muscles. The CSA of the quadriceps femoris muscle in the youngest age group was slightly larger (NS) than in the middle-aged group and much larger (P<0.41) than in the oldest age group whose CSA was markedly smaller (P<0.01) than the middle-aged group. Maximal force in the youngest group was slightly greater (NS) than in the middle-aged g…

Impaired muscle strength in female adolescents and young adults surviving leukemia in childhood

1993

Background. With the improving cure rate in childhood malignancies, increasing interest has been focused on long-term survivors. To evaluate late sequelae of childhood leukemia, the muscle strength of 43 young female survivors was investigated and compared with that of 69 healthy age-matched women. The patients had been off therapy for 1 to 19 years. Methods. The anthropometric characteristics measured were height and weight, and body mass index was calculated. The maximal isometric strengths for elbow flexion, knee extension, and hand grip were measured on a special dynamometer chair. Dynamic muscular endurance was measured by pushup and situp tests. Results. The mean height of the patient…

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…

Stability of the upper neck during isometric neck exercises in rheumatoid arthritis patients with atlantoaxial disorders.

2008

To study the effect of isometric neck strength exercises on upper cervical stability in patients with rheumatoid arthritis (RA).Twenty patients with a mean (SD) age of 58 (9) years and duration of RA of 27 (10) years volunteered for the study. Lateral radiographs of the cervical spine were taken to measure the current atlantoaxial distance (AAD) in flexion and extension. Maximal isometric neck flexion and extension strength values were measured by a dynamometer. Thereafter, AADs were measured from radiographs taken at 80-90% resistance of maximal strength.According to the full flexion radiographs at baseline, the patients were classified into three groups: eight patients without anterior at…

Active recovery shows favorable IGF-I and IGF binding protein responses following heavy resistance exercise compared to passive recovery

2019

IGF-I and IGFBPs have important physiological modulatory effects and this study sought to examine the influence of active vs. passive recovery following a heavy resistance exercise on IGF-I and IGF binding protein (IGFBP) recovery responses. It was hypothesized that increased IGF-I and decreased inhibitory IGFBPs during active recovery may be reflective of cascades promoting physiological recovery. 18 untrained men ((AR n = 7, PR n = 11), age: 26 ± 4 years, height: 174 ± 8 cm, body mass: 75 ± 13 kg) performed either a protocol-specific 10 × 10 × 30% 1RM active (AR) or passive recovery (PR) session following a heavy resistance exercise session performed on a leg press device (10 × 10 1RM). M…

Electromyographic Effect of Using Different Attentional Foci During the Front Plank Exercise

2018

Objective The aim of this cross-sectional study was to examine whether an internal focus on different core muscles during the isometric prone plank exercise increased muscle activity. Design Twenty university students performed the following five different conditions: regular prone plank (external focus) and prone plank with an internal focus on different muscles. Surface electromyography signals were recorded for the upper rectus abdominis, lower rectus abdominis, external oblique, and lumbar erector spinae. Results For the upper rectus abdominis, an internal focus on using any muscle increased activity. For the lower rectus abdominis, internal focus on any muscle except the lumbar erector…

Effects of a trail running competition on muscular performance and efficiency in well-trained young and master athletes

2010

International audience; To determine the acute effects of a trail running competition and the age-dependent differences between young and master athletes, 23 subjects [10 young (30.5 ± 7 years), 13 master (45.9 ± 5.9 years)] participated in a 55-km trail running competition. The study was conceived as an intervention study compromising pre, post 1, 24, 48 and 72 h measurements. Measurements consisted of blood tests, ergometer cycling and maximal isometric voluntary contractions (MVC). Parameters monitored included MVC, twitch-and M-wave properties, EMG (RMS) of the vastus lateralis, two locomotion efficiency calculations and muscle damage markers in the blood (CK, LDH). Results indicate pos…

Neuromuscular responses to explosive and heavy resistance loading

2000

The EMG power spectrum may shift towards higher frequencies with higher movement velocities. Fatigue, on the other hand, can cause a decrease in the frequency components. The purpose of this study was to examine acute effects of explosive (EE) and heavy resistance (HRE) concentric leg press exercise on muscle force, EMG and blood lactate. The EE included five sets of ten repetitions with 40+/-6% of the isometric maximum at a 100 degrees knee angle performed as explosively as possible. The same number of repetitions was performed in HRE but with a heavier load (67+/-7% of the isometric maximum at a 100 degrees knee angle). Maximal isometric and single concentric actions of different loads, a…