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1.
Brian Dawson Martin Fitzsimons Simon Green Carmél Goodman Michael Carey Keith Cole 《European journal of applied physiology and occupational physiology》1998,78(2):163-169
In contrast to endurance training, little research has been carried out to investigate the effects of short (<10 s) sprint
training on performance, muscle metabolism and fibre types. Nine fit male subjects performed a mean of 16 outdoor sprint running
training sessions over 6 weeks. Distances sprinted were 30–80 m at 90–100% maximum speed and between 20 and 40 sprints were
performed in each session. Endurance (maximal oxygen consumption; V˙O2
max), sprint (10 m and 40 m times), sustained sprint (supramaximal treadmill run) and repeated sprint (6 × 40 m sprints, 24 s
recovery between each) performance tests were performed before and after training. Muscle biopsy samples (vastus lateralis)
were also taken to examine changes in metabolites, enzyme activities and fibre types. After training, significant improvements
were seen in 40 m time (P < 0.01), supramaximal treadmill run time (P < 0.05), repeated sprint performance (P < 0.05) and V˙O2
max (P < 0.01). Resting muscle concentrations of ATP and phosphocreatine did not change. Phosphorylase activity increased (P < 0.025), citrate synthase activity decreased (P < 0.01), but no significant changes were recorded in myokinase and phosphofructokinase activities. The proportion of type
II muscle fibres increased significantly (P < 0.05). These results demonstrate that 6 weeks of short sprint training can improve endurance, sprint and repeated sprint
ability in fit subjects. Increases in the proportion of type II muscle fibres are also possible with this type of training.
Accepted: 5 January 1998 相似文献
2.
Michael Gleeson Andrew K. Blannin Neil P. Walsh Christine N. E. Field Jeanette C. Pritchard 《European journal of applied physiology and occupational physiology》1998,77(3):292-295
Eccentric muscle actions are known to induce temporary muscle damage, delayed onset muscle soreness (DOMS) and muscle weakness
that may persist for several days. The purpose of the present study was to determine whether DOMS-inducing exercise affects
blood lactate responses to subsequent incremental dynamic exercise. Physiological and metabolic responses to a standardised
incremental exercise task were measured two days after the performance of an eccentric exercise bout or in a control (no prior
exercise) condition. Ten healthy recreationally active subjects (9 male, 1 female), aged 20 (SD 1) years performed repeated
eccentric muscle actions during 40 min of bench stepping (knee high step; 15 steps · min−1). Two days after the eccentric exercise, while the subjects experienced DOMS, they cycled on a basket loaded cycle ergometer
at a starting work rate of 150 W, with increments of 50 W every 2 min until fatigue. The order of the preceding treatments
(eccentric exercise or control) was randomised and the treatments were carried out 2 weeks apart. Two days after the eccentric
exercise, all subjects reported leg muscle soreness and exhibited elevated levels of plasma creatine kinase activity (P < 0.05). Endurance time and peak V˙O2 during cycling were unaffected by the prior eccentric exercise. Minute volume, respiratory exchange ratio and heart rate
responses were similar but venous blood lactate concentration was higher (P < 0.05) during cycling after eccentric exercise compared with the control condition. Peak blood lactate concentration, observed
at 2 min post-exercise was also higher [12.6 (SD 1.4) vs 10.9 SD (1.3) mM; P < 0.01]. The higher blood lactate concentration during cycling exercise after prior eccentric exercise may be attributable
to an increased rate of glycogenolysis possibly arising from an increased recruitment of Type II muscle fibres. It follows
that determination of lactate thresholds for the purpose of fitness assessment in subjects experiencing DOMS is not appropriate.
Accepted: 27 September 1997 相似文献
3.
Michael S. Conley Michael H. Stone Michael Nimmons G. A. Dudley 《European journal of applied physiology and occupational physiology》1997,75(5):443-448
This study examined hypertrophy after head extension resistance training to assess which muscles of the complicated cervical
neuromuscular system were used in this activity. We also determined if conventional resistance exercises, which are likely
to evoke isometric action of the neck, induce generalized hypertrophy of the cervical muscle. Twenty-two active college students
were studied. [mean (SE) age, weight and height: 21 (1) years, 71 (4) kg and 173 (3) cm, respectively]. Subjects were assigned
to one of three groups: RESX (head extension exercise and other resistance exercises), RES (resistance exercises without specific
neck exercise), or CON (no training). Groups RESX (n = 8) and RES (n = 6) trained 3 days/week for 12 weeks with large-muscle mass exercises (squat, deadlift, push press, bent row and mid-thigh
pull). Group RESX also performed three sets of ten repetitions of a head extension exercise 3 days/week with a load equal
to the 3 × 10 repetition maximum (RM). Group CON (n = 8) was a control group. The cross-sectional area (CSA) of nine individual muscles or muscle groups was determined by magnetic
resonance imaging (MRI) of the cervical region. The CSA data were averaged over four contiguous transaxial slices in which
all muscles of interest were visible. The 3 × 10 RM for the head extension exercise increased for RESX after training [from
17.9 (1.0) to 23.9 (1.4) kg, P < 0.05] but not for RES [from 17.6 (1.4) to 17.7 (1.9)␣kg] or CON [from 10.1 (2.2) to 10.3 (2.1) kg]. RESX showed an increase
in total neck muscle CSA after training [from 19.5 (3.0) to 22.0 (3.6) cm2, P < 0.05], but RES and CON did not [from 19.6 (2.9) to 19.7 (2.9)␣cm2 and 17.0 (2.5) to 17.0 (2.4) cm2, respectively]. This hypertrophy for RESX was due mainly to increases in CSA of 23.9 (3.2), 24.0 (5.8), and 24.9 (5.3)% for
the splenius capitis, and semispinalis capitis and cervicis muscles, respectively. The lack of generalized neck muscle hypertrophy
in RES was not due to insufficient training. For example, the CSA of their quadriceps femoris muscle group, as assessed by
MRI, increased by 7 (1)% after this short-term training (P < 0.05). The results suggest that: (1) the splenius capitis, and semispinalis capitis and cervicis muscles are mainly responsible
for head extension; (2) short-term resistance training does not provide a sufficient stimulus to evoke neck muscle hypertrophy
unless specific neck exercises are performed; and (3) the postural role of head extensors provides modest loading in bipeds.
Accepted: 15 October 1996 相似文献
4.
Keisho Katayama Yasitake Sato Koji Ishida Shigeo Mori Miharu Miyamura 《European journal of applied physiology and occupational physiology》1998,78(3):189-194
The present study was performed to investigate the effects of a combination of intermittent exposure to hypoxia during exercise
training for short periods on ventilatory responses to hypoxia and hypercapnia (HVR and HCVR respectively) in humans. In a
hypobaric chamber at a simulated altitude of 4,500 m (barometric pressure 432 mmHg), seven subjects (training group) performed
exercise training for 6 consecutive days (30 min · day−1), while six subjects (control group) were inactive during the same period. The HVR, HCVR and maximal oxygen uptake (V˙O2 max) for each subject were measured at sea level before (pre) and after exposure to intermittent hypoxia. The post exposure test
was carried out twice, i.e. on the 1st day and 1 week post exposure. It was found that HVR, as an index of peripheral chemosensitivity
to hypoxia, was increased significantly (P < 0.05) in the control group after intermittent exposure to hypoxia. In contrast, there was no significant increase in HVR
in the training group after exposure. The HCVR in both groups was not changed by intermittent exposure to hypoxia, while V˙O2 max increased significantly in the training group. These results would suggest that endurance training during intermittent exposure
to hypoxia depresses the increment of chemosensitivity to hypoxia, and that intermittent exposure to hypoxia in the presence
or absence of exercise training does not induce an increase in the chemosensitivity to hypercapnia in humans.
Accepted: 18 March 1998 相似文献
5.
Said Ahmaidi Janick Masse-Biron Brigitte Adam Dominique Choquet Michel Freville Jean-Pierre Libert Christian Prefaut 《European journal of applied physiology and occupational physiology》1998,78(2):170-176
This study assessed clinical and cardiorespiratory responses after an interval training programme in sedentary elderly adults
using the ventilatory threshold (V
th) as the index of exercise training intensity. A selection of 22 subjects were randomized into two groups: 11 subjects served
as the training group (TG) and the others as controls (CG). Maximal exercise tests were performed on a treadmill before (T0), each month (T1, T2) and after the 3-month interval training programme period (T3). The TG subjects were individually trained at the heart rate corresponding to V
th measured at T0, T1 and T2 as the breakpoint in the oxygen uptake-carbon dioxide production relationship. Their training programme consisted of walking/jogging
sessions on a running track twice a week. The sessions consisted of varying durations of exercise alternating with active
recovery in such a way that the subjects slowly increased their total exercise time from an initial duration of 30 min to
a final duration of 1 h. During training the heart rate was continuously monitored by a cardiofrequency meter. Compared with
the daily activities of the controls, no training programme-related injuries were observed in TG. Moreover, programme adherence
(73%) and attendance (97.3%) were high. The maximal oxygen uptake and V
th were increased in TG, by 20% (P<0.05) and 26% (P<0.01), respectively. Interval training at V
th also significantly increased maximal O2 pulse (P<0.05) and maximal ventilation (P<0.01). A significant decrease in submaximal ventilation (P<0.05) and heart rate (P<0.01) was also noted. These results would suggest that for untrained elderly adults, an interval training programme at the
intensity of V
th may be well-tolerated clinically and may significantly improve both maximal aerobic power and submaximal exercise tolerance.
Accepted: 6 January 1998 相似文献
6.
Response of plasma IL-6 and its soluble receptors during submaximal exercise to fatigue in sedentary middle-aged men 下载免费PDF全文
The pleiotropic cytokine interleukin-6 (IL-6) has been demonstrated to increase during exercise. Little is known regarding
the response of the soluble IL-6 receptors (sIL-6R and sgp130) during such exercise. The aim of the current study was to investigate
the response of plasma IL-6, sIL-6R and sgp130 during fatiguing submaximal exercise in humans. Twelve participants underwent
an incremental exercise test to exhaustion and one week later performed a submaximal exercise bout (96 ± 6% lactate threshold)
to volitional exhaustion. Blood samples taken at rest and immediately post exercise were analyzed for IL-6, sIL-6R and sgp130.
IL-6 increased (P < 0.01) by 8.4 ± 8.9 pg ml−1 (75.7%) during the exercise period. sIL-6R and sgp130 also increased (P < 0.05) by 2.7 ± 3.9 ng ml−1 (9.6%) and 37.7 ± 55.6 ng ml−1 (9.6%), respectively. The current study is the first investigation to demonstrate that alongside IL-6, acute exercise stress
results in an increase in both sIL-6R and sgp130. 相似文献
7.
The effects of a 1-month exercise program and magnesium supplementation on the adrenocorticotropic hormone and cortisol levels
were studied in young tae-kwon-do and sedentary subjects both at rest and exhaustion. The hormone levels were compared before
and after supplementation with 10 mg of magnesium (as magnesium sulfate) per kilogram of body weight. Both exercise and magnesium
supplements caused significant increases of the adrenocorticotropic hormone (p < 0.05). The cortisol levels were increased in training subjects receiving supplements (p < 0.05) but not so in subjects that either trained or received magnesium supplements in an independent manner. The cortisol
levels measured in resting individuals were higher in the supplemented and non-supplemented athletes than those in sedentary
subjects (p < 0.05). The results of this study show that exercise and/or magnesium supplementation causes a rise of the adrenocorticotropic
hormone, whereas cortisol is increased only as a result of combined exhaustion and magnesium supplements. 相似文献
8.
Lars R. McNaughton Brad Dalton Janine Tarr 《European journal of applied physiology and occupational physiology》1998,78(3):236-240
The aim of this research was to determine whether creatine supplementation at a dose of 20 g · day−1, given in 4 × 6-g doses (5 g creatine monohydrate and 1 g glucose) for 5 days, was effective in improving kayak ergometer
performances of different durations. Sixteen male subjects with the following characteristics [mean (SEM)]: age 21 (1.2) years,
height 170.2 (1.7) cm, weight 75.3 (2.3) kg, Σ8 skinfolds 59.3 (2.6) mm, and maximal oxygen consumption 67.1 ± (4.3) ml · kg ·
min−1, undertook three maximal kayak ergometer tests of 90, 150 and 300 s duration on a wind-braked kayak ergometer (CON). Two
groups were then randomly formed, with one group taking the supplement (SUP) while the other took a placebo (PLAC). No pre-test
differences existed between the SUP and the PLAC groups in any of the variables measured. After supplementation each group
then repeated the same kayak ergometer tests as performed previously and after a 4-week “washout period” the groups took either
the PLAC or SUP for another 5 days and then completed the final tests. The SUP group completed significantly more work than
either the CON or PLAC groups in all of the tests (90 s, P < 0.01; 150 s, P < 0.001; 300 s, P < 0.05). Body mass remained stable throughout the test period in both the CON and PLAC groups, but both were significantly
less than the SUP body mass of 77.3 (1.0) kg (P < 0.01). The results of this work indicate that creatine supplementation can significantly increase the amount of work accomplished
during kayak ergometer performance at durations ranging from 90 to 300 s.
Accepted: 8 January 1998 相似文献
9.
A. Ratkeviius A. Skurvydas E. Povilonis B. Quistorff J. Lexell 《European journal of applied physiology and occupational physiology》1998,77(5):462-468
The aims of this study were to investigate if low-frequency fatigue (LFF) dependent on the duration of repeated muscle contractions
and to compare LFF in voluntary and electrically induced exercise. Male subjects performed three 9-min periods of repeated
isometric knee extensions at 40% maximal voluntary contraction with contraction plus relaxation periods of 30 plus 60 s, 15
plus 30 s and 5 plus 10 s in protocols 1, 2 and 3, respectively. The same exercise protocols were repeated using feedback-controlled
electrical stimulation at 40% maximal tetanic torque. Before and 15 min after each exercise period, knee extension torque
at 1, 7, 10, 15, 20, 50 and 100 Hz was assessed. During voluntary exercise, electromyogram root mean square (EMGrms) of the vastus lateralis muscle was evaluated. The 20-Hz torque:100-Hz torque (20:100 Hz torque) ratio was reduced more after
electrically induced than after voluntary exercise (P < 0.05). During electrically induced exercise, the decrease in 20:100 Hz torque ratio was gradually (P < 0.05) reduced as the individual contractions shortened. During voluntary exercise, the decrease in 20:100 Hz torque ratio
and the increase in EMGrms were greater in protocol 1 (P < 0.01) than in protocols 2 and 3, which did not differ from each other. In conclusion, our results showed that LFF is dependent
on the duration of individual muscle contractions during repetitive isometric exercise and that the electrically induced exercise
produced a more pronounced LFF compared to voluntary exercise of submaximal intensity. It is suggested that compensatory recruitment
of faster-contracting motor units is an additional factor affecting the severity of LFF during voluntary exercise.
Accepted: 5 November 1997 相似文献
10.
Jens Jordan Ralph Beneke Mathias Hütler Alexander Veith Hermann Haller Friedrich C. Luft 《European journal of applied physiology and occupational physiology》1997,76(2):192-194
Intravascular adhesion of leucocytes plays a role in the pathogenesis of acute and chronic vascular disease. Regular aerobic
exercise seems to protect against vascular disease. Since leucocyte adhesion is mediated by integrins, we tested the hypothesis
that surface expression of the integrin adhesive receptors LFA-1 (cd11a/cd18), MAC-1 (cd11b/cd18), gp 150/95 (cd11c/cd18),
and VLA-4 (cd29/cd49) is decreased by moderate endurance exercise. Surface expression of integrins was measured by FACS analysis
in 19 healthy subjects (16 males, 3 females, 36.6 ± 8.7 years, 177.1 ± 7.5 cm, 70.3 ± 8.1 kg) before and after submaximal
exercise (3 h run) using monoclonal antibodies against cd11a, cd11b, cd11c, cd18, cd29 and cd49. In addition, we compared
resting integrin expression in this group with a group of sedentary subjects (19 males, 6 females, 29.3 ± 5.3 years). White
blood cell count increased from 5300 ml–1 to 9740 ml–1 during exercise (P<0.001). Nevertheless, the expression (indicated by the mean log fluorescence) of cd11a (94 ± 24 vs. 78 ± 14) and cd18 (128 ± 31
vs. 102 ± 21) on lymphocytes and of cd11a (104 ± 25 vs. 85 ± 16), cd11c (497 ± 171 vs. 408 ± 126) cd29 (109 ± 16 vs. 89 ± 16),
cd49 (69± 8 vs. 54 ± 11) on monocytes was decreased after exercise (all P<0.05). In contrast, integrin expression on granulocytes was not altered by exercise. Comparison of exercising and sedentary
subjects showed a significantly decreased expression of integrins in exercising subjects. Our results demonstrate that moderate
exercise leads to decreased expression of integrin receptors on leucocytes. This decreased expression of adhesion molecules
may result in decreased adhesion and infiltration of leucocytes into the vessel wall. This phenomenon may play a role in the
beneficial effect of moderate exercise in prevention of acute and chronic vascular disease.
Accepted: 18 March 1997 相似文献
11.
Vedat Cinar Rasim Mogulkoc Abdulkerim Kasim Baltaci 《Biological trace element research》2010,134(2):130-135
In the present study, experiments were designed to investigate if supplementation with calcium during 4 weeks had an effect
on blood parameters in sedentary male athletes at rest and exhaustion. Thirty healthy subjects of ages ranging from 18 to
22 years were included in the study. The subjects were separated into three groups, as follows: Group 1 consisted sedentary
athletes receiving 35 mg/kg/day calcium gluconate. Group 2 included subjects equally supplemented with calcium training 90 min/day
for 5 days/week. Group 3 were subject to the same exercise regime but did not receive calcium supplements. Blood parameters
were determined in the experimental subjects at rest and after exhaustion. The leukocyte count (WBC) of athletes in groups
2 and 3 were significantly higher at exhaustion (p < 0.05). There were no significant differences in the WBC of the two supplemented groups. The erythrocyte count (RBC) was
increased in the supplemented athletes after training (p < 0.05), but hemoglobin, hematocrit, and trombocyte levels remained unchanged. The mean corpuscular volume increased in the
calcium-supplemented group at rest (p < 0.05). These results suggest that calcium supplementation only causes increases in white and red blood cell counts in athletes
after exhaustion while other hematological parameters remain unchanged. 相似文献
12.
Sue L. Hooper Laurel Traeger Mackinnon Enid M. Ginn 《European journal of applied physiology and occupational physiology》1998,78(3):258-263
The 100-m and 400-m swim time, tethered swimming forces, mood states and self-ratings of well-being of 27 competitive swimmers
were measured before and after 4 weeks of intense training and after 1 week and 2 weeks of tapering for major competition.
The swimmers were divided into three groups. Each group completed one of three taper regimes similar to those currently performed
by swimmers in preparation for competition: (a) reduced training frequency according to each athlete's daily ratings of well-being,
(b) reduced training volume, and (c) reduced training volume and intensity. Significant improvements in the Profile of Mood
States measures of tension, depression and anger (P < 0.05) were observed after 1 week of tapering, with significant improvements in total mood disturbance and fatigue (P < 0.05) and peak tethered swimming force (P < 0.01) after 2 weeks. Non-significant improvements in 100-m and 400-m swim time (P > 0.05) were observed and no significant differences were revealed among the three tapering techniques. These data highlighted
the importance of providing sufficient recovery before competition, since 1 week of reduced training was not long enough to
maximise the benefits of tapering. However, none of the three types of tapering currently used by competitive swimmers could
be shown to be more beneficial than the others.
Accepted: 9 February 1998 相似文献
13.
Tatsuhisa Takahashi Yoshimi Miyamoto 《European journal of applied physiology and occupational physiology》1998,77(4):305-311
To examine the influence of light exercise on cardiac responses during recovery from exercise, we measured heart rate (HR),
stroke volume (SV), and cardiac output (Q˙
c) in five healthy untrained male subjects in an upright position before, during, and after 10-min steady-state cycle exercise
at an exercise intensity of 170 W, corresponding to a mean of 68 (SD 4)% of maximal oxygen uptake. The recovery phase was
evaluated separately for three different conditions: 10 min of complete rest (passive recovery), 7 min of pedalling at 20-W
exercise intensity followed by 3 min of rest (partially active recovery), and 7 min of pedalling at 40-W exercise intensity
followed by 3 min of rest (partially active recovery), on an upright cycle ergometer. The time courses of decreases in HR
in the two active recovery phases at different exercise intensities were almost identical to those in the passive recovery
phase. However, the subsequent HR reductions during the rest after active recovery at 20 W and at 40 W were mean 7.5 (SD 4.4)
and mean 10.0 (SD 3.1) beats · min−1, respectively, both of which were significantly larger (P<0.05 and P<0.005) than the corresponding reduction [1.4 (SD 2.5) beats · min−1] for passive recovery. The SV values at the two exercise intensities during the active recovery periods were maintained at
levels similar to that during 170-W steady-state exercise. In contrast, the SV during passive recovery decreased gradually
to a level significantly below the initial baseline level at rest before exercise (P<0.05). The resultant time courses of CO values during active recovery were significantly higher (each P<0.05) than that during passive recovery. It was concluded from these findings that light post-exercise physical activity
plays an important role in facilitating the venous return from the muscles and in restoring the elevated HR to the pre-exercise
resting level.
Accepted: 17 September 1997 相似文献
14.
Thierry Weissland P. Pelayo Jacques Vanvelcenaher Ga?lle Marais Jean-Marc Lavoie Hervé Robin 《European journal of applied physiology and occupational physiology》1997,76(5):428-433
The aims of the present study were: first, to assess the interindividual variations of a spontaneously chosen crank rate
(SCCR) in relation to the power developed during an incremental upper body exercise on an arm ergometer set at a constant
power regime, and second, to compare heart rate (HR) responses, expired minute ventilation (V˙
E) and oxygen consumption (V˙O2) when the pedal rates were chosen spontaneously (TSCCR) or set at ±10% of the freely chosen rates (T+10% and T−10%, respectively). The mean pedal rate values were linearly related (P < 0.01) with the power developed during arm cranking (r = 0.96), although large variations of pedalling rate strategies were observed between subjects. Maximal power (MP) and time
to exhaustion values were significantly higher (P < 0.05) during TSCCR than during T+10% and T−10%. Peak V˙O2 values were significantly higher (P < 0.05) in T+10% than in TSCCR and T−10%. The increase in HR, V˙
E, and V˙O2 mean values, in relation to the increase in the power developed, was significantly higher (P < 0.05) when the pedal rate was set at plus 10% of the SCCR (T±10%) than in the two other conditions. The findings of the present study suggest that the use of an electromagnetically braked
ergometer, which automatically adjusts the resistance component to maintain a constant work rate, should be used in order
to achieve the highest MP values during an incremental upper body exercise. A 10% increase of the SCCR should be used in order
to provide the highest peak V˙O2 value.
Accepted: 5 May 1997 相似文献
15.
H. J. Bogaard H. H. Woltjer B. M. Dekker A. R. J. van Keimpema P. E. Postmus P. M. J. M. de Vries 《European journal of applied physiology and occupational physiology》1997,75(5):435-442
Whereas with advancing age, peak heart rate (HR) and cardiac index (CI) are clearly reduced, peak stroke index (SI) may decrease,
remain constant or even increase. The aim of this study was to describe the patterns of HR, SI, CI, arteriovenous difference
in oxygen concentration (C
a-vO2), mean arterial pressure (MAP), systemic vascular resistance index (SVRI), stroke work index (SWI) and mean systolic ejection
rate index (MSERI) in two age groups (A: 20–30 years, n = 20; B: 50–60 years n = 20. After determination of pulmonary function, an incremental bicycle exercise test was performed, with standard gas-exchange
measurements and SI assessment using electrical impedance cardiography. The following age-related changes were found: similar
submaximal HR response to exercise in both groups and a higher peak HR in A than in B[185 (SD 9) vs 167 (SD 14) beats · min−1, P < 0.0005]; increase in SI with exercise up to 60–90 W and subsequent stabilization in both groups. As SI decreased towards
the end of exercise in B, a higher peak SI was found in A [57.5 (SD 14.0) vs 43.6 (SD 7.7) ml · m−2, P < 0.0005]; similar submaximal CI response to exercise, higher peak CI in A [10.6 (SD 2.5) vs 7.2 (SD 1.3) l · min−1 · m−2, P < 0.0005]; no differences in C
a-vO2 during exercise; higher MAP at all levels of exercise in B; higher SVRI at all levels of exercise in B; lower SWI in B after
recovery; higher MSERI at all levels of exercise in A. The decrease in SI with advancing age would seem to be related to a
decrease in myocardial contractility, which can no longer be compensated for by an increase in preload (as during submaximal
exercise). Increases in systemic blood pressure may also compromise ventricular function but would seem to be of minor importance.
Accepted: 24 September 1996 相似文献
16.
M. Gleeson N. P. Walsh A. K. Blannin P. J. Robson L. Cook A. E. Donnelly S. H. Day 《European journal of applied physiology and occupational physiology》1998,77(6):543-546
The aim of this study was to determine if severe exercise-induced muscle damage alters the plasma concentrations of glutamine
and zinc. Changes in plasma concentrations of glutamine, zinc and polymorphonuclear elastase (an index of phagocytic cell
activation) were examined for up to 10 days following eccentric exercise of the knee extensors of one leg in eight untrained
subjects. The exercise bout consisted of 20 repetitions of electrically stimulated eccentric muscle actions on an isokinetic
dynamometer. Subjects experienced severe muscle soreness and large increases in plasma creatine kinase activity indicative
of muscle fibre damage. Peak soreness occurred at 2 days post-exercise and peak creatine kinase activity [21714 (6416) U · l−1, mean (SEM)] occurred at 3 days post-exercise (P < 0.01 compared with pre-exercise). Plasma elastase concentration was increased at 3 days post-exercise compared with pre-exercise
(P < 0.05), and is presumably indicative of ongoing phagocytic leucocyte infiltration and activation in the damaged muscles.
There were no significant changes in plasma zinc and glutamine concentrations in the days following eccentric exercise. We
conclude that exercise-induced muscle damage does not produce changes in plasma glutamine or zinc concentrations despite evidence
of phagocytic neutrophil activation.
Accepted: 3 November 1997 相似文献
17.
J. Langfort R. Zarzeczny W. Pilis K. Nazar H. Kaciuba-Ucitko 《European journal of applied physiology and occupational physiology》1997,76(2):128-133
The aim of this study was to find out whether a low-carbohydrate diet (L-CHO) affects: (1) the capacity for all-out anaerobic
exercise, and (2) hormonal and metabolic responses to this type of exercise. To this purpose, eight healthy subjects underwent
a 30-s bicycle Wingate test preceded by either 3 days of a controlled mixed diet (130 kJ/kg of body mass daily, 50% carbohydrate,
30% fat, 20% protein) or 3 days of an isoenergetic L-CHO diet (up to 5% carbohydrate, 50% fat, 45% protein) in a randomized
order. Before and during 1 h after the exercise venous blood samples were taken for measurement of blood lactate (LA), β-hydroxybutyrate
(β-HB), glucose, adrenaline (A), noradrenaline (NA) and insulin levels. Oxygen consumption (V˙O2) was also determined. It was found that the L-CHO diet diminished the mean power output during the 30-s exercise bout [533
(7) W vs 581 (7) W, P < 0.05] without changing the maximal power attained during the first or second 5-s interval of the exercise. In comparison
with the data obtained after the consumption of a mixed diet, after the consumption of a L-CHO diet resting plasma concentrations
of β-HB [2.38 (0.18) vs 0.23 (0.01) mmol · l−1, P < 0.001] and NA [4.81 (0.68) vs 2.2 (0.31) nmol · l−1, P < 0.05] were higher, while glucose [4.6 (0.1) vs 5.7 (0.2) mmol · l−1, P < 0.05] and insulin concentrations [11.9 (0.9) vs 21.8 (1.8) mU · l−1] were lower. The 1-h post-exercise excess of V˙O2 [9.1 (0.25) vs 10.6 (0.25) l, P < 0.05], and blood LA measured 3 min after the exercise [9.5 (0.4) vs 10.6 (0.5) mmol · l−1, P < 0.05] were lower following the L-CHO treatment, whilst plasma NA and A concentrations reached higher values [2.24 (0.40) vs
1.21 (0.13) nmol · l−1 and 14.30 (1.41) vs 8.20 (1.31) nmol · l−1, P < 0.01, respectively]. In subjects on the L-CHO diet, the plasma β-HB concentration decreased quickly after exercise, attaining
≈30% of the pre-exercise value within 60 min, while insulin and glucose levels were elevated. The main conclusions of this
study are: (1) a L-CHO diet is detrimental to anaerobic work capacity, possibly because of a reduced muscle glycogen store
and decreased rate of glycolysis; (2) reduced carbohydrate intake for 3 days enhances activity of the sympathoadrenal system
at rest and after exercise.
Accepted: 31 January 1997 相似文献
18.
Theodore J. Angelopoulos Rebecca Lewis Thanassis Jamurtas Chris Schumann 《European journal of applied physiology and occupational physiology》1998,77(6):556-559
We characterized the effect of ten days of training on lipid metabolism in 6 [age 37.2 (2.3) years] sedentary, obese [BMI
34.4 (3.0) kg · m−2] males with normal glucose tolerance. An oral glucose tolerance test was performed prior to and at the end of the 10 d of
training period. The duration of each daily exercise session was 40 min at an intensity equivalent to ˜75% of the age predicted
maximum heart rate. Blood measurements were performed after an overnight fast, before and at the end of the 10 d period. Plasma
triacylglycerol was significantly (p < 0.05) reduced following exercise training (2.15 ± 0.29 vs. 1.55 ± 0.28 mmol · l−1). Very low density lipoprotein-triacylglycerol was also significantly (p < 0.05) reduced (1.82 ± 0.3 vs. 1.29 ± 0.29 mmol · l−1). No significant changes in high density lipoprotein-cholesterol were observed as a result of training. Following training
fasting plasma glucose and fasting plasma insulin were significantly reduced [Glucose: 5.9 (0.2) mmol · l−1 vs. 5.3 (0.22) mmol · l−1 (p < 0.05); Insulin 264.3 (53.8) ρ · mol · l−1 vs. 200.9 (30.1) ρ · mol · l−1, p = 0.05]. The total area under the glucose curve during the OGTT decreased significantly (p < 0.05). These preliminary data suggest that short-term exercise, without concomitant loss of body mass, induces favorable
changes in plasma triacylglycerol, and very low density lipoprotein-triacylglycerol and glucose tolerance but has no effect
on high density lipoproteincholesterol.
Accepted: 7 January 1998 相似文献
19.
Timothy J. Carroll Peter J. Abernethy Peter A. Logan Margaret Barber Michael T. McEniery 《European journal of applied physiology and occupational physiology》1998,78(3):270-275
Seventeen subjects performed resistance training of the leg extensor and flexor muscle groups two (2/wk) or three (3/wk)
times per week. Changes in the relative myosin heavy chain (MHC) isoform contents (I, IIa and IIx) of the vastus lateralis
and isometric, isokinetic and squat-lift one-repetition maximum (1RM) strength were compared between conditions after both
a common training period (6 weeks) and number of training sessions (18). After 6 weeks and 18 sessions (9 weeks for the 2/wk
group), increments in 1RM strength for the 3/wk and 2/wk groups were similar [effect size (ES) differences ≈0.3, 3/wk > 2/wk],
whereas the 2/wk group presented greater isokinetic (ES differences = 0.3–1.2) and isometric (ES differences ≈0.7) strength
increases than the 3/wk condition. A significant (P < 0.05) increase in MHC IIa percentage was evident for the 2/wk group after 18 sessions. Both training groups exhibited a
trend towards a reduction in the relative MHC IIx and an increase in MHC IIa contents (ES range = 0.5–1.24). However, correlations
between changes in the strength and MHC profiles were weak (r
2: 0.0–0.5). Thus, isometric and isokinetic strength responses to variations in training frequency differed from 1RM strength
responses, and changes in strength were not strongly related to alterations in relative MHC content.
Accepted: 19 March 1998 相似文献
20.
A. Zembron-Lacny M. Slowinska-Lisowska Z. Szygula Z. Witkowski K. Szyszka 《Journal of physiology and biochemistry》2010,66(1):15-21
The aim of this study was to follow up whether the modification of pro-antioxidant status by 8-day oral application of N-acetylcysteine
(NAC) in healthy men affects the haematological response, whether there is a direct relationship between antioxidant defences
and erythropoietin (EPO) secretion and whether NAC intake enhances exercise performance. Fifteen healthy men were randomly
assigned to one of two groups: control or NAC (1,200 mg d−1 for 8 days prior to and 600 mg on the day of exercise trial). To measure the ergogenic effectiveness of NAC, subjects performed
incremental cycle exercise until exhaustion. NAC administration significantly influenced the resting and post-exercise level
of glutathione (+31%) as well as the resting activity of glutathione enzymes (glutathione reductase, −22%; glutathione peroxidase,
−18%). The oxidative damage markers, i.e., protein carbonylation and lipid peroxidation products (thiobarbituric acid reactive
substance) were reduced by NAC by more than 30%. NAC noticeably affected the plasma level of EPO (+26%), haemoglobin (+9%),
haematocrit (+9%) and erythrocytes (−6%) at rest and after exercise. The mean corpuscular volume and the mean corpuscular
haemoglobin increased by more than 12%. Plasma total thiols increased by 17% and directly correlated with EPO level (r = 0.528, P < 0.05). NAC treatment, contrary to expectations, did not significantly affect exercise performance. Our study has shown that
8-day NAC intake at a daily dose of 1,200 mg favours a pro-antioxidant status and affects haematological indices but does
not enhance exercise performance. 相似文献