Search results for "Lactates"
showing 10 items of 106 documents
Reduced reflex sensitivity persists several days after long-lasting stretch-shortening cycle exercise
1999
The mechanisms related to the acute and delayed secondary impairment of the stretch reflex function were investigated after long-lasting stretch-shortening cycle exercise. The results demonstrated a clear deterioration in muscle function immediately after fatigue, which was accompanied by a clear reduction in active and passive reflex sensitivity. For active and passive stretch reflexes, this reduction was biphasic ( P < 0.05 to P < 0.001). However, for the ratio of the electrically induced maximal Hoffmann reflex to the maximal mass compound action potential, only one significant reduction was seen immediately after fatigue (71.2%, P < 0.01). A similar significant ( P < 0.01) d…
Significance of hyperlactatemia in acute hypnotic drug poisoning
1981
Lactate concentration, fibrinogen and fibrin(ogen) -- degradation-products in central venous blood were analysed in 35 unconscious patient with acute hypnotic drug poisoning (HDP) and compared with the results in 13 healthy control persons undergoing the same degree of forced diuresis via central venous catheters. Blood samples were taken on admission and at 12 h intervals up to 36 h after admission. Patients with HDP were attributed to the categories of moderate intoxications (n = 17) and severe intoxications (n = 18) according to their clinical condition. On admission, blood lactate was significantly higher in severe intoxication (3.90 +/- 2.94 mmol/l) as compared to the control group (1.…
A Comparative Study of Blood Lactate Tests in Swimming*
1989
Three different modes of lactate tests were studied. Eleven male competitive swimmers performed the tests (n.100 m, n.300 m, 2.100m + 2.400 m) within 5 days. Swimming velocity (V) vs blood lactate (BLa) and V vs heart rate (HR) curves were averaged. In V vs BLa comparisons, the BLa values of 4 mmol.l-1 in 2.400 m, 3 mmol.l-1 in n.300 m, and 2 mmol.l-1 in n.100 m modes were found to correspond to the same V. Although the resting BLa values were similar before the testing occasions, the initial BLa value in very easy swimming was lower in the n.300 m than in the n.100 m mode. The elimination of lactate most probably caused this difference. The highest BLa value was measured in the n.100 m (14…
Endocrine Response Patterns to Acute Unilateral and Bilateral Resistance Exercise in Men
2009
Rehabilitation programs and research experiments use single-arm protocols in which the contralateral arm is not functional or used as a control limb. This study was interested in determining the hormonal signal impacts of such one- versus two-arm exercise responses that might have an impact on adaptational changes with training. The purpose was to examine the acute hormonal responses to a unilateral and a bilateral upper-body resistance exercise (RE) protocol. A balanced randomized treatment intervention with series time frame for blood collections before and after exercise was used as the basic experimental design. Ten recreationally resistance trained men (18-25 years, 20.4 +/- 1.2 years,…
Reproducibility of aerobic and anaerobic thresholds in 20-50 year old men.
1984
The reproducibility of the aerobic (AerT) and the anaerobic (AnT) threshold was studied in 33 men aged 20–50 years. They completed two maximal exercise tests on a bicycle ergometer. The thresholds, as $$\dot V_{O_2 }$$ (l·min−1), were determined visually by two investigators using both the blood lactate and the respiratory indices. The respiratory variables were measured with a computerized breath-by-breath method; samples of venous blood were drawn every 2nd min and analysed enzymatically for lactate. The reproducibility of the AerT (r=0.94) and of the AnT (r=0.96) were equally good. The AnT can be determined either from blood lactate concentrations (AnTLa) or from ventilatory and gas exch…
The effect of training on aerobic power characteristics of young cross-country skiers.
1987
The influences of growth, training and various training methods were investigated by analysing long-term training effects in young cross-country and biathlon skiers (n = 129). Some athletes (n = 49) were studied six times in three years and some at least once a year during a four year period (n = 48). During three summer training periods skiers emphasized either intensive training or distance training or continued to train normally. The results indicated that maximal oxygen uptake (VO2 max) and heart volume increased between 15 and 20 years of age and the most significant changes in heart volume were observed between 16 and 18 years of age. International level skiers were able to increase t…
Acute hormonal responses to submaximal and maximal heavy resistance and explosive exercises in men and women.
2005
The purpose of this study was to examine acute hormonal and neuromuscular responses in men and women to 3 heavy resistance but clearly different exercise protocols: (a) submaximal heavy resistance exercise (SME), (b) maximal heavy resistance exercise (HRE), and (c) maximal explosive resistance exercise (EE). HRE included 5 sets of 10 repetition maximum (10RM) situps, bench press, and bilateral leg extensions (David 210 machine) with a 2-minute recovery between the sets. In SME, the load was 70%, and in EE, the load was 40% from that used in HRE. A significant increase (p , 0.05) in serum growth hormone (GH) was observed after HRE both in men and women, but the increase was greater (p < 0.05…
Neuromuscular characteristics and fatigue in endurance and sprint athletes during a new anaerobic power test
1994
The purpose of this study was to investigate neuromuscular and energy performance characteristics of anaerobic power and capacity and the development of fatigue. Ten endurance and ten sprint athletes performed a new maximal anaerobic running power test (MARP), which consisted ofn x 20-s runs on a treadmill with 100-s recovery between the runs. Blood lactate concentration [la−]b was measured after each run to determine submaximal and maximal indices of anaerobic power (P 3mmol·1 −1,P5mmol·1 −1,P10mmol·1 −1andP max) which was expressed as the oxygen demand of the runs according to the American College of Sports Medicine equation: the oxygen uptake (ml·kg−1·min−1)=0.2·velocity (m·min−1) +0.9·s…
Skeletal muscle fibre types, enzyme activities and physical performance in young males and females
1978
Differences in skeletal muscle characteristics, metabolic profiles and functional performance between males and females were investigated using young (15--24 yrs) male and female twins as subjects. The comparison included such variables as anthropometry, muscle strength, mechanical power, maximum oxygen uptake, electrical activation of muscle, muscle fibre composition (m. vastus lateralis), and activities of several skeletal muscle enzymes. The results disclosed the following primary differences between males and females: In the various functional tests the performance of females was from 61.1 to 84.6% of that in males; distribution of slow twitch fibres in m. vastus lateralis of the female…
Acute hormonal responses to heavy resistance exercise in strength athletes versus nonathletes.
2004
The aim of the present study was to investigate acute hormonal and neuromuscular responses and recovery in strength athletes versus nonathletes during heavy resistance exercise performed with the forced and maximum repetitions training protocol. Eight male strength athletes (SA) with several years of continuous resistance training experience and 8 physically active but non-strength athletes (NA) volunteered as subjects. The experimental design comprised two loading sessions: maximum repetitions (MR) and forced repetitions (FR). MR included 12-RM squats for 4 sets with a 2-min recovery between sets. In FR the initial load was higher than in MR so that the subject could lift approximately 8 …