Rowing performance of female and male rowers

This study evaluated the rowing performance of female and male rowers with regard to their body size. Body height, body mass, fat-free mass, maximal oxygen uptake (VO2max), and "2000-m" rowing ergometer performance were measured in 71 females (age range 18-24 years, height 153-173 cm, body mass 43-69 kg, fat-free mass 34-55 kg; VO2max 2.1-3.9 L min(-1); 2000-m time 437-556 s) and 120 males (age 18-24 years, height 164-193 cm, body mass 58-95 kg, fat-free mass 50-81 kg; VO2max 3.4-5.6 L min(-1); 2000-m time 378-484 s). Rowing performance was correlated to body height (r=-0.81, P<0.001), body mass (r=-0.85, P<0.001), fat-free mass (r=-0.91, P<0.001), and VO2max (r=-0.90, P<0.001). However, rowing time was slower in the females than in the males with a similar body height (by approximately 10%) and body mass (by approximately 9%), but the sex difference was smaller when the fat-free mass (by approximately 4%) and VO2max (by approximately 4%) were matched. This study suggests that individuals with large body size and aerobic capacity possess an advantage for a 2000-m row on an ergometer. However, among females and males the variation in body size and aerobic capacity cannot explain the entire sex difference in ergometer rowing performance.     

Effects of training on functional performance in 65, 75 and 85 year-old women: experiences deriving from community based studies in Odense,Denmark

The aim of the Odense training studies is to elucidate if regular physical training influences the expected decline in physical functional ability in order to assess capacity for postponing dependence in old age. All participants were healthy community-dwelling women representing three different age-cohorts of 65, 75 and 85 year-old subjects. The 65 and 85 year-old participants of the training group took part in physical class-based exercises for eight months with one session of 60 min a week, whereas the 75 year-old women trained twice a week over eight months. The multicomponent training consisted of various exercises typically involving body awareness, rhythm, aerobic performance (walking), muscle strength and muscle endurance, flexibility, reaction and balance exercises. Physical ability was measured as physical performance test (PPT), isometric muscle strength of the trunk, hip and leg, aerobic capacity and walking speed. This shows that regular training can significantly improve physical ability of elderly women with regard to PPT, maximal oxygen uptake and maximal walking speed, suggesting that both young-old and old-old women are able to benefit from regular tailored exercise training. Thus, physical training of old community-dwelling women appears to represent a prophylactic remedy that merits further research aimed at evaluating the preliminary findings of the present studies in larger, less selective groups of participants.     

Why phase III trials of maximal androgen blockade versus castration in M1 prostate cancer rarely show statistically significant differences

BACKGROUND: The meta-analysis of maximal androgen blockade (MAB) concluded that there is no survival advantage of MAB over castration alone. However, the results from the largest trials yield conflicting results. METHODS: The design and results of three trials were examined. RESULTS: Most studies were planned to detect an over-optimistic difference in survival and immature data were published. The survival curves show that statistical assumptions are not fulfilled. Excluding from the meta-analysis all trials where a negative impact of disease flare on survival could not be excluded resulted in no difference in survival between MAB and castration. CONCLUSIONS: Trials of MAB should be planned to detect differences of no more than 5-10% in median survival. The analyses should only be carried out on mature data and should take into account the possibility of a negative impact on survival due to disease flare if no anti-androgen has been given initially with an LH-RH agonist.     

Beta-adrenergic blockade and training in healthy men—effects on central circulation

The effect of chronic β-adrenergic blockade on central circulatory adaptations to physical training was investigated. 16 healthy sedentary males (20–31 yrs) trained on cycle ergometers 40 min/day, 4 days a week for 8 weeks at a work load that during the last 5 weeks corresponded to 75% of the pretraining VO₂ max. In a single blind way, 8 subjects were during the training period treated with the β-adrenergic receptor blocker propranolol (160 mg/day), while the remaining 8 received placebo tablets. Pretraining tests were performed before the start of medication and posttraining tests were performed 6 days after the last day of training and medication. The training program resulted in a similar increase (8%) in VO₂ max in both groups (p<0.01). The resting heart rate (-4 beats/min; p<0.05) as well as the exercise heart rate at a moderate work load (120 W: -11 beats/min; p<0.01) decreased with training, and no significant difference was seen between the 2 groups. At a high work load (180 W), however, the heart rate decreased significantly more with training in the placebo group as compared with the β-blockade group (-19 vs.-7 beats/min; p<0.05). The oxygen pulse (VO₂/HR) increased in both groups at 120 W (+6%; p<0.01). At 180 W the oxygen pulse increased only in the placebo group (+8%; p<0.05). The estimated stroke volume at 120 and 180 W, as determined by impedance cardiography, did not change significantly with training although there was a tendency towards an increase in the placebo group only. The resting left ventricular wall thickness and diameter, as determined by echocardiography, did not change significantly with training in either group.—In conclusion, the present study indicates that a moderate degree of β-adrenergic blockade does not prevent or impair the training-induced increase in the maximal oxygen uptake. During submaximal work, however, the circulatory adaptation may be less apparent if training has been performed during partial blockade of the sympathoadrenal system.     

中国北方汉族男子CKB基因单核苷酸多态性与耐力训练效果关联研究

目的:探讨中国北方平原地区汉族男子脑型肌酸激酶(CKB)基因多态性与耐力训练效果的关联性。方法:102名无训练史的健康男子进行18周有氧耐力训练,测试训练前后的最大摄氧量、跑节省化(RE)各指标。用PCR-RFLP法分析CKB基因启动子上rs3759582和rs3759584两位点的单核苷酸多态性。结果:二个多态位点均符合H-W平衡,不存在强的连锁关系;训练后rs3759582位点AA基因型最大摄氧量变化率、跑节省化变化率与AC基因型组间均无显著性差异(P>0.05);训练后rs3759584位点TT基因型△RE/VO2、△RE/rVO2、△RE/HR和△RE/VE显著低于CT和CC基因型(P<0.05),但是CC基因型频率仅为3%。结论:CKB基因的rs3759582多态性不是预测个体耐力训练敏感性的基因标记;rs3759584与个体的耐力训练敏感性相关,但需加大样本进一步确认。     

The physiology of world‐class sprint skiers

The present study investigated the physiological characteristics of eight world‐class (WC) and eight national‐class (NC) Norwegian sprint cross country skiers. To measure the physiological response and treadmill performance, the skiers performed a submaximal test, a peak aerobic capacity (VO_2peak) test, and a peak treadmill speed (V_peak) test in the skating G3 technique. Moreover, the skiers were tested for G3 acceleration outdoors on asphalt and maximal strength in the lab. The standard of sprint skating performance level on snow was determined by International Ski Federation points, and the training distribution was quantified. WC skiers showed 8% higher VO_2peak and twice as long a VO₂ plateau time at the VO_2peak test, and a higher gross efficiency at the submaximal test (all P<0.05). Furthermore, WC skiers showed 8% higher V_peak (P<0.05), but did not differ from NC skiers in acceleration and maximal strength. WC skiers performed more low‐ and moderate‐intensity endurance training and speed training (both P<0.05). The current results show that aerobic capacity, efficiency, and high speed capacity differentiate WC and NC sprint skiers and it is suggested that these variables determine sprint skiing performance.     

局限高危前列腺癌患者接受全雄激素阻断联合近距离治疗后的PSA变化模式与其生存预后的临床关联分析

目的:探讨前列腺癌(PCa)患者治疗后PSA变化模式对其生存预后的临床影响。方法:回顾性总结近12年来114例接受全雄激素阻断(MAB)联合近距离治疗的PCa患者的临床资料,从PSA变化规律入手,初步分析患者生存预后的影响因素。结果:患者中位生存时间81(15~144)个月,1、3、5年生存率分别为91.23%、78.07%和68.42%。单因素分析显示:基线PSA水平、PSA最低值、PSA下降时间、PSA倍增时间以及PSA缓解幅度均是可能影响生存预后的临床因素。多因素分析显示:PSA最低值、PSA下降时间以及PSA缓解幅度是独立的预后因素,并分别提高了患者远期生存可能1.7、3.3和6.8倍。结论:局限高危PCa患者在接受MAB联合近距离治疗后,其PSA能否降至1μg/L以下、能否在3个月之内降至最低值,以及PSA最大缓解幅度能否达到96%等因素均是影响患者预后的独立风险因素。     

Efficacy of maximal androgen blockade versus castration alone in the treatment of advanced prostate cancer： a retrospective clinical experience from a Chinese medical centre

In this retrospective study, we evaluated and compared the efficacy and toxicities of maximal androgen blockade （MAB） versus castration alone in Chinese patients with advanced prostate cancer. From 1996 to 2004, 608 patients with advanced prostate cancer were included in the study. Patients were retrospectively divided into two groups according to different therapeutic regimens. Of the 608 patients, 300 patients were treated with MAB （castration plus nonsteroidal antiandrogens） and the remaining 308 were treated with castration alone. The 2- and 5-year overall survival rates of these patients were 73.7% and 56%, respectively. Multivariate analysis showed that, in patients with metastatic prostate cancer, MAB was associated with not only the improvement of progression-free survival （PFS） （increased by 10 months） but also a 20.6% reduction in mortality risk compared with castration alone. In contrast, the efficacy of MAB was not superior to castration alone for patients with nonmetastatic prostate cancer. Interestingly, among patients with MAB, those using bicalutamide had a longer PFS than those using flutamide; this was especially so in patients with metastatic prostate cancer. Almost all of the toxicities due to the hormone therapy were mild to moderate and manageable. To conclude, in China, hormone therapies, including MAB and castration alone, have been standard treatments for advanced prostate cancer. For patients with nonmetastatic prostate cancer, castration alone might be adequately practical and efficient. In patients with metastatic prostate cancer, however, MAB has superior efficacy over castration alone. It is clear that MAB should be considered the first-line standard treatment for patients with metastatic prostate cancer.     

Aerobic exercise capacity at sea level and at altitude in Kenyan boys, junior and senior runners compared with Scandinavian runners

The aim of this study was to characterize Kenyan runners in regard to their oxygen uptake and blood and ammonia responses when running. Untrained Kenyan boys (14.2±0.2 years) and Scandinavian runners were included for comparison. The studies were performed at altitude (～2.000 m.a.s.l.) and, for several Kenyan and Scandinavian runners, at sea level as well. At altitude sedentary adolescent Kenyan boys had a mean maximal oxygen uptake (Vo_2max) of 47 (44–51) ml · kg^?1· min^?1, whereas similarly aged boys regularly walking or running but not training for competition reached above 62 (58–71) ml · kg^?1· min^?1 in Vo^2max. Kenyan runners in active training had 68±1.4 ml · kg^?1· min^?1 at altitude and 79.9±1.4 ml · kg^?1· min^?1 at sea level, with individuals reaching 85 ml · kg^?1· min^?1. The best Scandinavian runners were not significantly different from the Kenyan runners in Vo_2max both at altitude and at sea level, but none of the Scandinavians reached as high individual values as observed for some Kenyan runners. The running efficiency, determined as the oxygen cost at a given running speed, was less in the Kenyan runners, and the difference became more pronounced when body weight was expressed in ml · kg^?0.75 min^?1. Blood lactate concentration was in general lower in the Kenyan than in the Scandinavian runners, and the Kenyans also had extremely low ammonia accumulation in the blood even at very high exercise intensities. It is concluded that it is the physical activity during childhood, combined with intense training as teenagers that brings about the high Vo_2max observed in some Kenyan runners. Their high aerobic capacity, as well as their good running economy, makes them such superior runners. In addition, their low blood lactate and ammonia accumulation in blood when running may also be contributing factors.     

The prognostic value of maximal exercise testing soon after first myocardial infarction

The prognostic value of ST-segment depression during maximalexercise test performed in the third to fourth week after acutemyocardial infarction (AMI), was studied in 126 consecutivepatients with no evidence of previous myocardial infarction,unstable angina pectoris or severe heart failure. All patientson average increased their pressure-rate product by 2.6 andno complications occurred. Within the first year of follow-up,major cardiac events occurred in 9 patients (20%), and werefatal in 6 (13%), of the 46 patients who developed ST-segmentdepression during exercise. Only 3 major cardiac events (4%)occurred in the 80 patients without exercise induced ST-segmentdepression. Depression of the ST-segment on maximal exercisewas a significant predictor of subsequent cardiac events inthese survivors of first AMI.