首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
The psychobiological status of cyclists over a period of 8 months of training was assessed by measuring the sympatho-adrenal level, the central noradrenergic activity, and the cortisol-testosterone ratio status noninvasively. Alteration of these indices after a large increase in training load lasting 4 days (+ 187%) was also examined. Urinary excretion of methoxyamines (metanephrine, normetanephrine) and 3-methoxy-4-hydroxyphenylglycol sulphate (MHPG-S), and salivary concentrations of cortisol and testosterone, were measured in 12 national cyclists after a non-specific training period and 48 h before 4 days of increased training (T1), after these 4 days (T2) and at the end of 4 months of specific training (T3). Urinary and salivary samples were also collected during a rest period (T0). At each of these times, mood states and ratings of perceived muscle soreness were assessed, and a questionnaire of early clinical symptoms of the overtraining syndrome (Profile of Mood States) was administered. A significant increase in normetanephrine (P < 0.05) and a decrease in the testosterone-cortisol ratio (P < 0.05) were observed at T2, while MHPG-S excretion remained unchanged. Over the same periods, increased training loads did not induce mood disturbances. Eight months of training were associated with significant alterations in metanephrine (P < 0.05) and MHPG-S (P < 0.05). These results suggest a dissociation between the neural and endocrine catecholaminergic components systems. Opposite responses between MHPG-S and Profile of Mood States scores show that further investigations are needed to understand the relationship between central noradrenergic function, which is recognized as a regulatory factor of mood, and psychological tests measuring mood.  相似文献   

2.
Abstract

In this study, we investigated the effect of 1- and 3-week tapering periods on concentrations of plasma testosterone (T), cortisol (C), T/C ratio, mood state, and performance in elite male cyclists. After 8 weeks of progressive training, cyclists were randomly assigned to a control group (n=12) who continued performing intense training for a further 3 weeks, or a taper group (n=12) who continued with a 50% reduction in training volume. Blood testosterone and cortisol concentrations were assayed and the T/C ratio calculated from analysis obtained via standard ELISA. Mood state was determined using the Profile of Mood States (POMS) questionnaire. All data were collected immediately after a 40-km time-trial performed before, during, and after the 8-week training protocol and after the 1- and 3-week tapering/training periods. In the taper group, 40-km time-trial time decreased significantly (P<0.01) and equally for both the 1- and 3-week taper periods relative to the control group. There were significant elevations in T/C ratio (P<0.001) and reductions in cortisol concentrations and POMS scores in the taper group relative to the control groups at the end of both the 1- and 3-week tapering periods. Hence, taper periods are effective in improving performance and mood state and elevating the blood T/C ratio.  相似文献   

3.
Abstract

In this study, we examined the effect of rapidly increased training volume and intensity on hormonal responses (salivary cortisol [C] and urinary dehydroepiandrosterone sulphate [DHEA-S]) and recovery-stress state perceived by 12 female cyclists. Over the 4-day experimental period, there was an average increase in training load of approximately 122% compared with that during the previous 12 days. Scores on subscales of the Recovery Stress Questionnaire for Athletes increased for the somatic component of stress (Fatigue, Emotional Stress and Social Stress; P < 0.05) and decreased the factor indicating recovery (General Well Being; P < 0.05) after the heavy training period. The training programme increased resting concentrations of salivary cortisol (P < 0.05) and decreased the DHEA-S/C ratio (P < 0.05). The increase in training load of cyclists was correlated with this hormonal ratio (r = ?0.48, P < 0.05). Changes in resting cortisol concentration as a result of heavy training stress were positively related to the change in Physical Complaints (r = 0.69, P < 0.01). Negative relationships were also found between changes in the DHEA-S/C ratio and changes in the somatic component of stress. The present results suggest that there is a dose–response relationship between increased training load, resting DHEA-S/C ratio and subjective assessment of stress and recovery, implying that this ratio could be used as an indicator of training status in female athletes.  相似文献   

4.
Abstract

Based on research suggesting that nanomaterial containing nanodiamond- and nanoplatinum-coated fibres (DPV576-C) may reduce the stress response, garments to enhance athletes’ recovery from training-induced stress have been manufactured. This study examined the effects of wearing recovery garments on the physical and psychological stress of Japanese male baseball players. Thirty-eight players aged 18–21 (19.6?±?0.2 years) who participated in a two-week intensified training programme were randomly assigned to two groups: 19 wore recovery (DPV576-C) garments (RG group) and 19 wore non-recovery garments (placebo group). Both groups wore the garments overnight. Mood states, using the Profile of Mood States questionnaire, and salivary cortisol levels were measured before (day 0) and after (day 14) the training period. Saliva samples were collected from 07:00–07:30 am. Both groups’ fatigue scores significantly increased after the training period (RG: 8.4?±?0.8–10.1?±?0.8 score; placebo: 9.8?±?1.0–11.7?±?1.0 score). The total mood disturbance (TMD) score increased significantly in the placebo group (21.0?±?2.3–27.2?±?3.0 score) but not in the RG group (17.4?±?2.7–20.2?±?2.2 score). Salivary cortisol concentrations decreased significantly in the RG group (0.71?±?0.08–0.49?±?0.05?μg/dL) but not in the placebo group (0.61?±?0.06–0.58?±?0.10?μg/dL). Therefore, wearing the DPV576-C garments overnight attenuated increases in TMD levels and decreased salivary cortisol levels following intensified training. DPV576-C garments may have beneficial effects on training-induced physical and psychological stress among athletes.  相似文献   

5.
Abstract

The aim of the present study was to determine whether 4 months of intensified training would result in modified plasma insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 1 (IGFBP-1) or IGFBP-3 in eight competitive cyclists and eight sedentary individuals and to define the relationships of these factors with glucose disposal. Insulin sensitivity and glucose effectiveness — that is, the fractional disappearance of glucose independent of any change in insulinaemia — were measured with the minimal model (mathematical analysis of frequently sampled intravenous glucose tolerance test). Both glucose effectiveness and insulin sensitivity were higher in the cyclists than in the sedentary individuals, but did not increase further with training. IGF-I was higher in the cyclists than in the sedentary group only after training (P<0.05). Plasma IGFBP-1 and IGFBP-3 increased after training (38 and 20%, respectively; P<0.05) in the cyclists and were higher than in the sedentary individuals (P<0.05). IGF-I was negatively correlated with insulin sensitivity before and after training (r=?0.66 and ?0.67, respectively; P<0.05) and IGFBP-1 was negatively correlated with glucose effectiveness before and after training (r=?0.68 and ?0.77, respectively; P<0.05). Our results show that strenuous endurance training improves the somatotrope axis (growth hormone—IGF) and that IGFBP-1 may be involved in glucose homeostasis, possibly by limiting the exercise-induced increase in glucose disposal, in competitive cyclists.  相似文献   

6.
ABSTRACT

Elite cyclists have often a limited period of time available during their short preparation phase to focus on development of maximal strength; therefore, the purpose of the present study was to investigate the effect of 10-week heavy strength training on lean lower-body mass, leg strength, determinants of cycling performance and cycling performance in elite cyclists. Twelve cyclists performed heavy strength training and normal endurance training (E&S) while 8 other cyclists performed normal endurance training only (E). Following the intervention period E&S had a larger increase in maximal isometric half squat, mean power output during a 30-s Wingate sprint (P < 0.05) and a tendency towards larger improvement in power output at 4 mmol ? L?1 [la?] than E (P = 0.068). There were no significant difference between E&S and E in changes in 40-min all-out trial (4 ± 6% vs. ?1 ± 6%, respectively, P = 0.13). These beneficial effects may encourage elite cyclists to perform heavy strength training and the short period of only 10 weeks should make it executable even in the compressed training and competition schedule of elite cyclists.  相似文献   

7.
Nine well-trained, unacclimatized female hockey players performed the Loughborough Intermittent Shuttle Test (LIST) interspersed with three field hockey skill tests in hot (30°C, 38% relative humidity) and moderate (19°C, 51% relative humidity) environmental conditions. Field hockey skill performance declined in both the hot and moderate conditions following 30 and 60?min of the LIST compared with pre-LIST values (P <?0.01). This decrement in performance was compounded in the hot environment with a 6% poorer performance in the heat recorded for the second skill test at 30?min (P <?0.05, hot 101.7?±?3.6 vs moderate 95.7?±?2.9?s; mean ±?s x). However, no difference was found in the decision-making element of the skill test. Fifteen-metre sprint times were slower in the hot condition (P <?0.01). In the hot environment, rectal temperature (P?<?0.01), perceived exertion (P?<?0.05), perceived thirst (P?<?0.01), blood glucose concentration (P?<?0.05) and serum aldosterone concentration (P?<?0.01) were higher. Estimated mean (?±?s x) sweat rate was higher in the hot trial (1.27?±?0.10?l?·?h?1) than in the moderate trial (1.05?±?0.12?l?·?h?1) (P?<?0.05). Body mass was well maintained in both trials. No differences in serum cortisol, blood lactate, plasma volume or plasma ammonia concentrations were found. These results demonstrate that field hockey skill performance is decreased following intermittent high-intensity shuttle running and that this decrease is greater in hot environmental conditions. The exact mechanism for this decrement in performance remains to be elucidated, but is unlikely to be due to low glycogen concentration or dehydration.  相似文献   

8.
Aim: The aim of this study was to examine the relationship between ventilatory adaptation and performance during altitude training at 2700?m. Methods: Seven elite cyclists (age: 21.2?±?1.1?yr, body mass: 69.9?±?5.6?kg, height 176.3?±?4.9?cm) participated in this study. A hypoxic ventilatory response (HVR) test and a submaximal exercise test were performed at sea level prior to the training camp and again after 15 d at altitude (ALT15). Ventilation (VE), end-tidal carbon-dioxide partial pressure (PETCO2) and oxyhaemoglobin saturation via pulse oximetry (SpO2) were measured at rest and during submaximal cycling at 250?W. A hill climb (HC) performance test was conducted at sea level and after 14 d at altitude (ALT14) using a road of similar length (5.5–6?km) and gradient (4.8–5.3%). Power output was measured using SRM cranks. Average HC power at ALT14 was normalised to sea level power (HC%). Multiple regression was used to identify significant predictors of performance at altitude. Results: At ALT15, there was a significant increase in resting VE (10.3?±?1.9 vs. 12.2?±?2.4?L·min?1) and HVR (0.34?±?0.24 vs. 0.71?±?0.49?L·min?1·%?1), while PETCO2 (38.4?±?2.3 vs. 32.1?±?3.3?mmHg) and SpO2 (97.9?±?0.7 vs. 94.0?±?1.7%) were reduced (P?VE at altitude as significant predictors of HC% (adjusted r2?=?0.913; P?=?0.003). Conclusions: Ventilatory acclimatisation occurred during a 2 wk altitude training camp in elite cyclists and a higher HVR was associated with better performance at altitude, relative to sea level. These results suggest that ventilatory acclimatisation is beneficial for cycling performance at altitude.  相似文献   

9.
Abstract

Power output and heart rate were monitored for 11 months in one female ([Vdot]O2max: 71.5 mL · kg?1 · min?1) and ten male ([Vdot]O2max: 66.5 ± 7.1 mL · kg?1 · min?1) cyclists using SRM power-meters to quantify power output and heart rate distributions in an attempt to assess exercise intensity and to relate training variables to performance. In total, 1802 data sets were divided into workout categories according to training goals, and power output and heart rate intensity zones were calculated. The ratio of mean power output to respiratory compensation point power output was calculated as an intensity factor for each training session and for each interval during the training sessions. Variability of power output was calculated as a coefficient of variation. There was no difference in the distribution of power output and heart rate for the total season (P = 0.15). Significant differences were observed during high-intensity workouts (P < 0.001). Performance improvements across the season were related to low-cadence strength workouts (P < 0.05). The intensity factor for intervals was related to performance (P < 0.01). The variability in power output was inversely associated with performance (P < 0.01). Better performance by cyclists was characterized by lower variability in power output and higher exercise intensities during intervals.  相似文献   

10.
Abstract

This study examined salivary cortisol and testosterone responses to two, different high-intensity, ～30-min cycles separated by 2 h rest before and after an 11-day intensified training period. Twelve recreationally active, healthy males completed the study. Saliva samples were collected before, immediately after and 30 min after both bouts with salivary cortisol and testosterone concentrations assessed. Compared with pre-training blunted exercise-induced salivary cortisol, testosterone and cortisol/testosterone responses to both bouts post-training were observed (P < 0.05 for all). Comparing pre- with post-training the absolute exercise-induced salivary cortisol, testosterone and cortisol/testosterone decreased from 11.1 to 3.1 and 7.0 to 4.4 nmol · L?1 (cortisol), from 407 to 258 and from 473 to 274 pmol · L?1 (testosterone) and from 12 to 4 and 7 to 5 (cortisol/testosterone) for the first and second bouts, respectively (P < 0.05). No differences in the pre- and post-training rating of perceived exertion (RPE) and heart rate (HR) responses during the cycles or times to fatigue were found (P > 0.05). Fatigue and Burnout scores were higher post- compared with pre-training (P < 0.05).

These high-intensity exercise bouts can detect altered hormonal responses following intensified training. This test could assess an athlete's current hormonal status, reductions in salivary cortisol and testosterone responses suggestive of increased fatigue.  相似文献   

11.
The aim of this cohort study is to analyse the effect of three types of treatment: (i) exercise training with multicomponent exercise (E); (ii) pharmacologic treatment with oral hypoglycaemic drug – metformin (M); and (iii) a combined therapy – exercise and metformin (E?+?M) on health-related quality of life (HRQoL) and mood states in older adults with type 2 diabetes (T2D) with comorbidity in an early stage of the disease. Participants (n?=?284) underwent 1 of the following 3 conditions: (i) E (n?=?59) trained three times/week; (ii) M (n?=?30) used 850?mg of metformin twice daily; and (iii) E?+?M (n?=?195) combined exercise and metformin. Furthermore, participants completed baseline and 2-year follow-up evaluations including a Shortform Health Survey 36, Profile of Mood States – Short-form, the health history questionnaires, anthropometric, and blood biochemistry. E and E?+?M revealed improved mood states, with large effect size on the vigour domain, and moderate effect size in the anger and total mood disturbance (TMD) domains (P?<?0.05), in comparison with the M group. After 24 months’ intervention, the E and E?+?M groups perceived better physical and mental HRQoL than the M group. The M group unchanged HRQoL domains (P?>?0.05). Metformin had no significant effect on the self-referred HRQoL in T2D participants aged above 60 years, in an early stage of the disease. The E and E?+?M were the most effective long-term therapies to improve mood states and HRQoL in older adults with T2D.  相似文献   

12.
The aim of this study was to determine the effects of caffeine ingestion on a ‘preloaded’ protocol that involved cycling for 2?min at a constant rate of 100% maximal power output immediately followed by a 1-min ‘all-out’ effort. Eleven male cyclists completed a ramp test to measure maximal power output. On two other occasions, the participants ingested caffeine (5?mg?·?kg?1) or placebo in a randomized, double-blind procedure. All tests were conducted on the participants' own bicycles using a Kingcycle? test rig. Ratings of perceived exertion (RPE; 6–20 Borg scale) were lower in the caffeine trial by approximately 1 RPE point at 30, 60 and 120?s during the constant rate phase of the preloaded test (P?<0.05). The mean power output during the all-out effort was increased following caffeine ingestion compared with placebo (794±164 vs 750±163?W; P?=?0.05). Blood lactate concentration 4, 5 and 6?min after exercise was also significantly higher by approximately 1?mmol?·?l?1 in the caffeine trial (P?<0.05). These results suggest that high-intensity cycling performance can be increased following moderate caffeine ingestion and that this improvement may be related to a reduction in RPE and an elevation in blood lactate concentration.  相似文献   

13.
Sports characterized by little or moderate weight bearing or impact have a low osteogenic effect. However, the action of such sports on bone turnover remains unclear. The objective of this study was to determine the effect on bone remodelling of physical activities that induce moderate external loading on the skeleton. Thirty-eight male athletes aged 18–39 years (cyclists, n?=?11; swimmers, n?=?13; triathletes, n?=?14) and 10 age-matched sedentary controls aged 22–35 years participated in the study. The study combined measurement of bone mineral density by dual-energy X-ray absorptiometry and bone turnover assessment from specific biochemical markers: serum bone-specific alkaline phosphatase, osteocalcin, urinary type I collagen C-telopeptide and calcium. Compared with the controls and swimmers, adjusted bone mineral density was higher (P?<?0.05) in triathletes at the total proximal femur and lower limbs. No differences in bone mineral density were found between cyclists, swimmers and controls. Compared with controls, osteocalcin was higher (P?<?0.05) in triathletes and swimmers and urinary type I collagen C-telopeptide was higher in swimmers only. Serum bone-specific alkaline phosphatase was lower (P?<?0.05) in cyclists than in all other groups. In conclusion, an osteogenic effect was found only in triathletes, mainly at bone sites under high mechanical stress. Bone turnover differed in athletes compared with controls, suggesting that bone turnover may be sport-practice dependent. Despite some encouraging observations, it was not possible to show that changes in the bone remodelling process were sport-discipline dependent.  相似文献   

14.
We studied the effect of psyching-up on one-repetition maximum (1-RM) performance and salivary cortisol responses during the squat exercise. Ten men (age 21.6?±?1.4 years; mean?±?s) and ten women (age 22.4?±?2.8 years) with weight training experience of 4.5?±?2.0 years participated in this study. One-repetition maximum squats were performed on a Smith machine during each of two different intervention conditions that were counterbalanced and consisted of a free choice psych-up and a cognitive distraction. Saliva samples were obtained at the beginning of each test session and immediately after the final 1-RM attempt. No significant difference in 1-RM was identified between psyching-up (104?±?50?kg) and cognitive distraction (106?±?52?kg). Performing a 1-RM in the squat exercise significantly increased salivary cortisol concentrations during both conditions (P <?0.05). There was no significant difference in salivary cortisol responses between conditions. These results suggest that psyching-up does not increase 1-RM performance during the squat exercise in strength-trained individuals.  相似文献   

15.
This study examined the effects of different work?–?rest durations during 40?min intermittent treadmill exercise and subsequent running performance. Eight males (mean?±?s: age 24.3?±?2.0 years, body mass 79.4?±?7.0?kg, height 1.77?±?0.05?m) undertook intermittent exercise involving repeated sprints at 120% of the speed at which maximal oxygen uptake (v-[Vdot]O2max) was attained with passive recovery between each one. The work?–?rest ratio was constant at 1:1.5 with trials involving short (6:9?s), medium (12:18?s) or long (24:36?s) work?–?rest durations. Each trial was followed by a performance run to volitional exhaustion at 150% v-[Vdot]O2max. After 40?min, mean exercise intensity was greater during the long (68.4?±?9.3%) than the short work?–?rest trial (54.9?±?8.1% [Vdot]O2max; P?<?0.05). Blood lactate concentration at 10?min was higher in the long and medium than in the short work?–?rest trial (6.1?±?0.8, 5.2?±?0.9, 4.5?±?1.3?mmol?·?l?1, respectively; P?<?0.05). The respiratory exchange ratio was consistently higher during the long than during the medium and short work?–?rest trials (P <?0.05). Plasma glucose concentration was higher in the long and medium than in the short work?–?rest trial after 40?min of exercise (5.6?±?0.1, 6.6?±?0.2 and 5.3?±?0.5?mmol?·?l?1, respectively; P?<?0.05). No differences were observed between trials for performance time (72.7?±?14.9, 63.2?±?13.2, 57.6?±?13.5?s for the short, medium and long work?–?rest trial, respectively; P = 0.17), although a relationship between performance time and 40?min plasma glucose was observed (P?<?0.05). The results show that 40?min of intermittent exercise involving long and medium work?–?rest durations elicits greater physiological strain and carbohydrate utilization than the same amount of intermittent exercise undertaken with a short work?–?rest duration.  相似文献   

16.
We compared the effects of (1) accurate and (2) surreptitiously augmented performance feedback on power output and physiological responses to a 4000 m time-trial in the heat. Nine cyclists completed a baseline (BaseL) 4000 m time-trial in ambient temperatures of 30°C, followed by two further 4000 m time-trials at the same temperature, randomly assigning the participants to an accurate (ACC; accurate feedback of baseline) or deceived (DEC; 2% increase above baseline) feedback group. The total power output (PO) and aerobic (Paer) and anaerobic (Pan) contributions were determined at 0.4 km stages during the time-trials, alongside measurements of rectal (Trec) and skin (Tskin) temperatures. There were no differences (P > 0.05) in any of the variables between BaseL, ACC and DEC, despite increases (P < 0.05) in Trec and Tskin. Typical pacing profiles were demonstrated; however, there was no interaction (P > 0.05) between feedback condition and time-trial stage. Providing surreptitiously augmented performance feedback to well-trained cyclists did not alter their performance or physiological responses to a 4000 m time-trial in a hot environment. The assumed influence of augmented performance feedback was nullified in the heat, perhaps reflecting a central down-regulation of exercise intensity in response to an increased body temperature.  相似文献   

17.
High Intensity Interval Training (HIIT) can be performed with different effort to rest time-configurations, and this can largely influence training responses. The purpose of the study was to compare the acute physiological responses of two HIIT and one moderate intensity continuous training (MICT) protocol in young men. A randomised cross-over study with 10 men [age, 28.3?±?5.5years; weight, 77.3?±?9.3?kg; height, 1.8?±?0.1?m; peak oxygen consumption (VO2peak), 44?±?11?mL.kg?1.min?1]. Participants performed a cardiorespiratory test on a treadmill to assess VO2peak, velocity associated with VO2peak (vVO2peak), peak heart rate (HRpeak) and perceived exertion (RPE). Then participants performed three protocols equated by distance: Short HIIT (29 bouts of 30s at vVO2peak, interspersed by 30s of passive recovery, 29?min in total), Long HIIT (3 bouts of 4?min at 90% of vVO2peak, interspersed by 3?min of recovery at 60% of vVO2peak, 21?min in total) and MICT (21?min at 70% of vVO2peak). The protocols were performed in a randomised order with ≥48 h between them. VO2, HRpeak and RPE were compared. VO2peak in Long HIIT was significantly higher than Short HIIT and MICT (43?±?11 vs 32?±?8 and 37?±?8?mL.kg?1.min?1, respectively, P?P?P?2, HR and RPE than Short HIIT and MICT, suggesting a higher demand on the cardiorespiratory system. Short HIIT and MICT presented similar physiologic and perceptual responses, despite Short HIIT being performed at higher velocities.  相似文献   

18.

Background and aim

This study examined the effects of a 6-week high-intensity interval training (HIIT) vs. low-intensity endurance training (LOW), applied during physical education on motor performance, mood and perceived exertion.

Methods

Over a period of 6 weeks, 85 pupils (34 male; 51 female; age: 11.9?±?0.9 years) performed 11 sessions of either HIIT (20?min, intervals from 10?s to 4?min at about 90–100% of average running speed of 6?min run [vmean]) or LOW (30?min, intervals from 6–25?min at about 65–85% vmean). Before and after the 6?week intervention each pupils’ anthropometry and motor performance (20?m sprint, standing long-jump, lateral jumping from side to side, push-ups, sit-ups, 6?min run) were assessed. Session rating of perceived exertion (RPE) was recorded after each session and mood was assessed by questionnaire following the 3rd, 6th, 9th and 11th session.

Results

RPE (p?<?0.05) was higher and mood more positive (p?<?0.05) with HIIT compared to LOW. Performances in the 6?min run (p?<?0.001; part. η2?=?0.473), 20?m sprint (p?<?0.001; part. η2?=?0.226), standing long-jump (p?<?0.05; part. η2?=?0.056), push-ups (p?<?0.001; part. η2?=?0.523) and sit-ups (p?<?0.001; part. η2?=?0.146) improved following HIIT and LOW with no significant time?×?group interaction (except for the sit-ups [p?<?0.05; part. η2?=?0.048]).

Conclusions

HIIT and LOW improved the performances in 6?min run, 20?m sprint, standing long-jump and push-ups similarly. However, the improvements in HIIT compared to LOW were achieved in 30% less time. As time is limited in physical education classes, HIIT offers a new perspective for improving endurance and motor performance in children. The positive mood associated with HIIT demonstrates the applicability in physical education.
  相似文献   

19.
The purpose of this study was to compare the pedalling technique in road cyclists of different competitive levels. Eleven professional, thirteen elite and fourteen club cyclists were assessed at the beginning of their competition season. Cyclists’ anthropometric characteristics and bike measurements were recorded. Three sets of pedalling (200, 250 and 300 W) on a cycle ergometer that simulated their habitual cycling posture were performed at a constant cadence (~90 rpm), while kinetic and kinematic variables were registered. The results showed no differences on the main anthropometric variables and bike measurements. Professional cyclists obtained higher positive impulse proportion (1.5–3.3% and P < 0.05), mainly due to a lower resistive torque during the upstroke (15.4–28.7% and P < 0.05). They also showed a higher ankle range of movement (ROM, 1.1–4.0° and P < 0.05). Significant correlations (P < 0.05) were found between the cyclists’ body mass and the kinetic variables of pedalling: positive impulse proportion (r = ?0.59 to ?0.61), minimum (r = ?0.59 to ?0.63) and maximum torques (r = 0.35–0.47). In conclusion, professional cyclists had better pedalling technique than elite and club cyclists, because they opted for enhancing pulling force at the recovery phase to sustain the same power output. This technique depended on cycling experience and level of expertise.  相似文献   

20.
The present study examined the effect of strength and endurance training order on the endocrine milieu associated with strength development and performance during concurrent training. A randomised, between-groups design was employed with 30 recreationally resistance-trained males completing one of four acute experimental training protocols; strength training (ST), strength followed by endurance training (ST-END), endurance followed by strength training (END-ST) or no training (CON). Blood samples were taken before each respective exercise protocol, immediately upon cessation of exercise, and 1?h post cessation of exercise. Blood samples were subsequently analysed for total testosterone, cortisol and lactate concentrations. Ability to maintain 80% 1RM during strength training was better in ST and ST-END than END-ST (both p?<?.05). Immediately following the respective exercise protocols all training interventions elicited significant increases in testosterone (p?<?.05). ST and END-ST resulted in greater increases in cortisol than ST-END (both p?<?.05). The testosterone:cortisol ratio was similar following the respective exercise protocols. Blood lactate concentrations post-training were greater following END-ST and ST than ST-END (both p?<?.05). Conducting endurance exercise prior to strength training resulted in impaired strength training performance. Blood cortisol and lactate concentrations were greater when endurance training was conducted prior to strength training than vice versa. As such, it may be suggested that conducting endurance prior to strength training may result in acute unfavourable responses to strength training when strength training is conducted with high loads.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号