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1.
The effect of training on aerobic power characteristics of young cross-country skiers 总被引：1，自引：0，他引：1
H Rusko 《Journal of sports sciences》1987,5(3):273-286
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 their VO2 max and heart volume even after 20 years of age. Anaerobic threshold (AT, ml kg-1 min-1) increased like VO2 max but when expressed as a percentage of VO2 max, the AT was similar in every age group over 16 years of age. Intensive training at the intensity of anaerobic threshold or higher was observed to be most effective in producing improvements in VO2 max. Low-intensity distance training was more effective in producing improvements in anaerobic threshold. 相似文献
2.
Heikki Rusko 《Journal of sports sciences》2013,31(3):273-286
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 their VO2 max and heart volume even after 20 years of age. Anaerobic threshold (AT, ml kg‐1 min‐1) increased like VO2 max but when expressed as a percentage of VO2 max, the AT was similar in every age group over 16 years of age. Intensive training at the intensity of anaerobic threshold or higher was observed to be most effective in producing improvements in VO2 max. Low‐intensity distance training was more effective in producing improvements in anaerobic threshold. 相似文献
3.
The aim of this study was to compare the 'anaerobic threshold' (AnT) of subjects determined during a continuous 2-min incremental exercise test until exhaustion and the 'maximal lactate steady-state' (BLaSsmax) determined during prolonged exercise at constant loads corresponding to the subjects' AnT and/or 5-25% above and below it. Seventeen subjects performed an incremental exercise test and 1-5 prolonged exercise tests on a cycle ergometer until exhaustion at intervals of 1 week, and work rates, oxygen uptake (VO2) values and brachial venous blood lactate (BLa) levels were measured. It was proposed that when exercising at a constant workload below AnT, BLa would fall after having reached its peak; at the level of AnT, BLa reaches maximal steady-state (BLaSsmax); and above AnT, BLa increases continuously. Altogether, in 34 of 45 tests with a constant workload between 80 and 125% AnT, BLa values were as expected. In those cases in which BLaSsmax was reached, BLa increased on average by 3.8 mM from resting levels. This increase was 2.0 mM greater than that seen between resting levels and AnT during incremental exercise. There was no correlation between BLa values at BLaSsmax and at AnT, both when expressed as an increase in BLa (delta BLa) and absolute BLa concentration. Altogether, 81% of the variation in BLa concentration at BLaSsmax could be explained by the subjects' age, the percentage of slow-twitch fibres and BLa levels at rest. The AnT and BLaSsmax did not differ significantly, and these values were correlated (r = 0.83). Together, AnT and age accounted for 85% of the variation seen in BLaSsmax. The BLaSsmax did not correlate with AnT when fixed at a BLa concentration of 4 mM (AnT4mM). The three hypotheses tested in this study were confirmed, and the present results demonstrate that AnT correlates with BLaSsmax. The few exceptions to anticipated BLa kinetics were small in magnitude and could be explained by physiological variations. 相似文献
4.
Acclimatization to altitude and normoxic training improve 400-m running performance at sea level 总被引：2，自引：0，他引：2
To investigate the benefits of 'living high and training low' on anaerobic performance at sea level, eight 400-m runners lived for 10 days in normobaric hypoxia in an altitude house (oxygen content = 15.8%) and trained outdoors in ambient normoxia at sea level. A maximal anaerobic running test and 400-m race were performed before and within 1 week of living in the altitude house to determine the maximum speed and the speeds at different submaximal blood lactate concentrations (3, 5, 7, 10 and 13 mmol x l(-1)) and 400-m race time. At the same time, ten 400-m runners lived and trained at sea level and were subjected to identical test procedures. Multivariate analysis of variance indicated that the altitude house group but not the sea-level group improved their 400-m race time during the experimental period (P < 0.05). The speeds at blood lactate concentrations of 5-13 mmol x l(-1) tended to increase in the altitude house group but the response was significant only at 5 and 7 mmol x l(-1) (P < 0.05). Furthermore, resting blood pH was increased in six of the eight altitude house athletes from 0.003 to 0.067 pH unit (P < 0.05). The results of this study demonstrate improved 400-m performance after 10 days of living in normobaric hypoxia and training at sea level. Furthermore, the present study provides evidence that changes in the acid-base balance and lactate metabolism might be responsible for the improvement in sprint performance. 相似文献
5.
The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (<2000-2200 m) and/or too short an altitude training period (<3-4 weeks); (2) the training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is >12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study. 相似文献
6.
Abstract The aim of this study was to compare the ‘anaerobic threshold’ (AnT) of subjects determined during a continuous 2‐min incremental exercise test until exhaustion and the ‘maximal lactate steady‐state’ (BLaSsmax) determined during prolonged exercise at constant loads corresponding to the subjects’ AnT and/or 5–25% above and below it. Seventeen subjects performed an incremental exercise test and 1–5 prolonged exercise tests on a cycle ergometer until exhaustion at intervals of 1 week, and work rates, oxygen uptake (VO2) values and brachial venous blood lactate (BLa) levels were measured. It was proposed that when exercising at a constant workload below AnT, BLa would fall after having reached its peak; at the level of AnT, BLa reaches maximal steady‐state (BLaSsmax); and above AnT, BLa increases continuously. Altogether, in 34 of 45 tests with a constant workload between 80 and 125% AnT, BLa values were as expected. In those cases in which BLaSsmax was reached, BLa increased on average by 3.8 mM from resting levels. This increase was 2.0 mM greater than that seen between resting levels and AnT during incremental exercise. There was no correlation between BLa values at BLaSsmax and at AnT, both when expressed as an increase in BLa (ABLa) and absolute BLa concentration. Altogether, 81% of the variation in BLa concentration at BLaSsmax could be explained by the subjects’ age, the percentage of slow‐twitch fibres and BLa levels at rest. The AnT and BLaSsmax did not differ significantly, and these values were correlated (r = 0.83). Together, AnT and age accounted for 85% of the variation seen in BLaSsmax. The BLaSsmax did not correlate with AnT when fixed at a BLa concentration of 4 mM (AnT4mM). The three hypotheses tested in this study were confirmed, and the present results demonstrate that AnT correlates with BLaSsmax. The few exceptions to anticipated BLa kinetics were small in magnitude and could be explained by physiological variations. 相似文献
7.
To develop a track version of the maximal anaerobic running test, 10 sprint runners and 12 distance runners performed the test on a treadmill and on a track. The treadmill test consisted of incremental 20-s runs with a 100-s recovery between the runs. On the track, 20-s runs were replaced by 150-m runs. To determine the blood lactate versus running velocity curve, fingertip blood samples were taken for analysis of blood lactate concentration at rest and after each run. For both the treadmill and track protocols, maximal running velocity (v max), the velocities associated with blood lactate concentrations of 10 mmol x l-1 (v10 mM) and 5 mmol x l(-1) (v5 mM), and the peak blood lactate concentration were determined. The results of both protocols were compared with the seasonal best 400-m runs for the sprint runners and seasonal best 1000-m time-trials for the distance runners. Maximal running velocity was significantly higher on the track (7.57 +/- 0.79 m x s(-1)) than on the treadmill (7.13 +/- 0.75 m x s(-1)), and sprint runners had significantly higher vmax, v10 mM, and peak blood lactate concentration than distance runners (P < 0.05). The Pearson product--moment correlation coefficients between the variables for the track and treadmill protocols were 0.96 (v max), 0.82 (v10 mM), 0.70 (v5 mM), and 0.78 (peak blood lactate concentration) (P < 0.05). In sprint runners, the velocity of the seasonal best 400-m run correlated positively with vmax in the treadmill (r = 0.90, P < 0.001) and track protocols (r = 0.92, P < 0.001). In distance runners, a positive correlation was observed between the velocity of the 1000-m time-trial and vmax in the treadmill (r = 0.70, P < 0.01) and track protocols (r = 0.63, P < 0.05). It is apparent that the results from the track protocol are related to, and in agreement with, the results of the treadmill protocol. In conclusion, the track version of the maximal anaerobic running test is a valid means of measuring different determinants of sprint running performance. 相似文献
8.
To investigate the benefits of ‘living high and training low' on anaerobic performance at sea level, eight 400-m runners lived for 10 days in normobaric hypoxia in an altitude house (oxygen content = 15.8%) and trained outdoors in ambient normoxia at sea level. A maximal anaerobic running test and 400-m race were performed before and within 1 week of living in the altitude house to determine the maximum speed and the speeds at different submaximal blood lactate concentrations (3, 5, 7, 10 and 13 mmol· l-1) and 400-m race time. At the same time, ten 400-m runners lived and trained at sea level and were subjected to identical test procedures. Multivariate analysis of variance indicated that the altitude house group but not the sea-level group improved their 400-m race time during the experimental period (P ? 0.05). The speeds at blood lactate concentrations of 5–13 mmol· l-1 tended to increase in the altitude house group but the response was significant only at 5 and 7 mmol·l-1 (P ? 0.05). Furthermore, resting blood pH was increased in six of the eight altitude house athletes from 0.003 to 0.067 pH unit (P ? 0.05). The results of this study demonstrate improved 400-m performance after 10 days of living in normobaric hypoxia and training at sea level. Furthermore, the present study provides evidence that changes in the acid–base balance and lactate metabolism might be responsible for the improvement in sprint performance. 相似文献
9.
The neural activation (iEMG) and selected stride characteristics of six male sprinters were studied for 100-, 200-, 300- and 400-m experimental sprints, which were run according to the velocity in the 400 m. Blood lactate (BLa) was analysed and drop jumps were performed with EMG registration at rest and after each sprint. Running velocity (P less than 0.001) and stride length (P less than 0.05) decreased and contact time increased (P less than 0.01) during the 400-m sprint. The increase in contact time was greatest immediately after runs of 100 and 300 m. The peak BLa increased and the rate of BLa accumulation decreased with running distance (P less than 0.001). The height of rise of the centre of mass in the drop jumps was smaller immediately after the 300 m (P less than 0.05) and the 400 m (P less than 0.01) than at rest, and it correlated negatively with peak BLa (r = -0.77, P less than 0.001). The EMG and EMG:running velocity ratio increased with running distance. It was concluded that force generation of the leg muscles had already begun to decrease during the first quarter of the 400-m sprint. The deteriorating force production was compensated for until about 200-300 m. Thereafter, it was impossible to compensate for fatigue and the speed of running dropped. According to this study, fatigue in the 400-m sprint among trained athletes is mainly due to processes within skeletal muscle rather than the central nervous system. 相似文献
10.
Altitude and endurance training 总被引：4，自引：0，他引：4
The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (< 2000-2200 m) and/or too short an altitude training period (<3-4 weeks); (2) the training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is > 12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study. 相似文献