Maximal heart rate declines linearly with age independent of cardiorespiratory fitness levels

There have been many conflicting observations between the linear or curvilinear decline in maximal heart rate (HR_max) with age. The aim of this study was to determine if linear or curvilinear equations would better describe the decline in HR_max with age in individuals of differing cardiorespiratory fitness (CRF) levels. Treadmill cardiopulmonary exercise test (CPX) results from participants (1510 men and 1134 women; 18–76 years) free of overt cardiovascular disease were retrospectively examined using cross-sectional and longitudinal study designs. Participants completing ≥2 CPX with ≥1 year between test dates were included in the longitudinal analysis (325 men and 150 women). Linear and quadratic regressions were applied to age and HR_max for the whole cohort and respective CRF groups (high, moderate, and low, relative to age and gender normative values). To test for differences among linear, quadratic, and polynomial equations, the change in R² (cross-sectional analysis) and Bayesian information criterion (BIC) (longitudinal analysis) from the linear to the more complex models were calculated. The quadratic or polynomial regression in the cross-sectional analysis, marginally improved the variance in HR_max explained by age compared to the linear regression for the whole cohort (0.2%), moderate fit group (0.3%), and low fit group (0.8%). With no improvements in the high fit group. BIC did not improve for any CRF category in the longitudinal analysis. In conclusion, the minimal differences among linear, quadratic, and polynomial equations in the respective CRF groups, emphasizes the use of linear prediction equations to estimate HR_max.     

高强度运动对心脏的冲击影响及信号提取研究

设计实时的肌肉组织血氧量和瞬时心率无损同步检测方案与设备,为研究高强度运动心脏的冲击影响、探讨高强度运动中代谢规律提供测试手段。方法:采用连续双波长近红外光测量肌肉中血红蛋白与肌红蛋白含氧量的变化情况;采用芬兰SUUNTO心率带和自行设计的转发器及配套PC软件测量瞬时心率,进行了100m跑同步实测试验。结果:100m跑以无氧代谢为主。起跑后的前7s为无氧代谢的非乳酸功能,肌氧饱和度曲线变化不大。7s后开始消耗肌肉中储存的氧。结论:双波长近红外光组织氧测试法和运动心率无线实时采集系统能够正确实时同步地检测高强度运动时血氧和心率,揭示了高强度运动过程中肌肉中氧的运输与消耗及心率之间的动力学过程。     

省青少年比赛中篮球裁判员运动强度影响因素的研究

探讨比赛中篮球裁判员心率与年龄和体重等指标的关系;进一步比较不同级别篮球裁判员在比赛中生理指标的变化特征。对不同级别裁判员的赛中心率变化分析表明：在省青少年篮球比赛中,裁判级别对心率分布、最高心率和平均心率等指标无明显影响。相关分析表明篮球裁判员在省青少年比赛中的心率指标与年龄、体重以及级别之间无相关关系。     

Thermoneutral immersion exercise accelerates heart rate recovery: A potential novel training modality

This study compared heart rate recovery (HRR) after incremental maximal exercise performed at the same external power output (P_ext) on dry land ergocycle (DE) vs. immersible ergocycle (IE). Fifteen young healthy participants (30?±?7 years, 13 men and 2 women) performed incremental maximal exercise tests on DE and on IE. The initial P_ext on DE was 25?W and was increased by 25?W/min at a pedalling cadence between 60 and 80?rpm, while during IE immersion at chest level in thermoneutral water (30°C), the initial P_ext deployment was at a cadence of 40?rpm which was increased by 10?rpm until 70?rpm and thereafter by 5?rpm until exhaustion. Gas exchange and heart rate (HR) were measured continuously during exercise and recovery for 5?min. Maximal HR (DE: 176?±?15 vs. IE 169?±?12?bpm) reached by the subjects in the two conditions did not differ (P?>?.05). Parasympathetic reactivation parameters (ΔHR from 10 to 300?s) were compared during the DE and IE HR recovery recordings. During the IE recovery, parasympathetic reactivation in the early phase was more predominant (HRR at Δ10–Δ60?s, P?<?.05), but similar in the late phase (HRR at Δ120–Δ300?s, P?>?.05) when compared to the DE condition. In conclusion, incremental maximal IE exercise at chest level immersion in thermoneutral water accelerates the early phase parasympathetic reactivation compared to DE in healthy young participants.     

花剑运动员技术训练与模拟比赛训练课的心率特征分析

以福建省花剑运动员为研究对象,对花剑运动员的技术训练课和模拟比赛课全程进行实时心率测试分析,认为模拟比赛训练课能达到实战训练强度的要求,有利于高水平运动员提高技战术的实战能力,技术训练课负荷强度较低,适合于技术水平较低的运动员,应根据不同技术水平的运动员合理安排技术训练课与模拟比赛训练课的比重。     

Effects of official youth taekwondo competitions on jump and strength performance

Abstract

The aim of this study was to investigate differences in athletes’ (7 females, 10 males) motor performances (countermovement jump and handgrip) before and after official youth (13–14 years) taekwondo matches. Exercise load was evaluated by means of the heart rate responses during the match. Independent of round and gender, during the competitions mean heart rate was 187 beats·min^?1 (s=11). During the match, the frequency of heart rate responses above 85% of an individual's maximum heart rate was 77% (s=27). Jump performances showed differences for gender (P=0.044; ES = 0.47) and its interaction with session (P=0.045; ES = 0.49). Female athletes’ post-match countermovement performances were no different from their pre-match performances (pre and post: 22 cm, s=2), whereas male athletes post-match performances (28 cm, s=6) were better than their pre-match performances (25 cm, s=6). Handgrip performances related to the body mass of the athletes showed main effects for session (P=0.017; ES = 0.20) and for gender (P=0.026; ES = 0.47), with no significant interaction. Male athletes showed higher handgrip values (5.8 N·kg^?1, s=0.6) than their female counterparts (5.1 N·kg^?1, s=0.7). For absolute grip strength performances, values were higher pre-match (290.3 N, s=61.4) than post-match (272.4 N, s = 58.3). The heart rate responses indicate that official youth taekwondo competition imposes a high load on athletes. In particular, post-match decreases in isometric grip strength suggest that coaches should better prepare their very young athletes to prevent reductions in muscle force during fighting. Considering that lower limb power remained unaffected or increased depending on gender, further research in this area is strongly recommended.     

高原运动员在次高原比赛期间静息心率及体重变化状况的分析

本文通过青海业余运动员云南昆明比赛期间晨静息心率、晨空腹体重和问卷调查的分析,发现：高原地区运动员即使向高原地区较低海拔移动较少的高度,也会产生有利于心血管方面的影响,运动员本体感觉好于原居住地;返回原居住地后,缺氧对机体也有刺激作用;在身体机能的变化中,机体对心血管系统的变化更为敏感,     

运动训练对自发性高血压大鼠心肌细胞凋亡蛋白表达的影响

目的:研究运动训练对SHR心肌细胞中HSP-72、Bcl-2和蛋白激酶β(PKB)、Bax、糖原合成激酶-3(GSK-3)的影响,以探讨其对运动引起心肌细胞凋亡的作用。方法:以SHR大鼠中等强度训练为实验模型,采用Western bloting技术检测了大鼠心肌细胞中调控蛋白HSP-72、Bcl-2和蛋白激酶β(PKB)、Bax、糖原合成激酶-3(GSK-3)的表达。结果:长期中等强度训练可以提高心肌细胞中抑凋亡蛋白HSP-72、Bcl-2和蛋白激酶β(PKB)的表达,凋亡蛋白Bax、糖原合成激酶-3(GSK-3)表达显著降低,Bcl-2/Bax的表达没有显著变化,从而抑制心肌细胞的凋亡。结论:心肌细胞中HSP-72、Bcl-2和蛋白激酶β(PKB)、Bax、糖原合成激酶-3(GSK-3),Bcl-2/Bax在运动后的不同表达对心肌细胞凋亡的发生有明显的抑制作用。     

4周下肢间歇负压干预对优秀赛艇运动员心率变异性和儿茶酚胺的影响

目的探讨下肢间歇负压干预对赛艇运动员心率变异性(HRV)相关指标和儿茶酚胺的影响。方法将国家赛艇队的14名运动员分为试验组和对照组,试验组运动员每周用间歇负压干预5 d,持续4周,对照组无其他干预方式。试验期间均对2组运动员进行HRV相关指标和儿茶酚胺的测试。结果试验前2组运动员各指标均无统计学差异。开始干预后2组的变化如下:①在时域指标中,试验组正常窦性R-R间期标准差(SDNN)在第3周时高于对照组(P<0.05)。②在频域指标中,试验组高频(HF)值在第2周和第3周时高于对照组(P<0.05),而其高频与低频比(LF/HF)在第1、3和4周时低于对照组(P<0.05)。③2组儿茶酚胺组内、组间比较均无统计学差异,但试验组儿茶酚胺下降程度比对照组高。结论 4周的间歇负压干预对运动员自主神经系统功能的恢复有明显促进作用,对儿茶酚胺的分泌也具有抑制趋势;这有利于降低运动员心脏负荷,促进运动后的生理恢复。     

Physiological and biomechanical responses to walking underwater on a non-motorised treadmill: effects of different exercise intensities and depths in middle-aged healthy women

Abstract

Non-motorised underwater treadmills are commonly used in fitness activities. However, no studies have examined physiological and biomechanical responses of walking on non-motorised treadmills at different intensities and depths. Fifteen middle-aged healthy women underwent two underwater walking tests at two different depths, immersed either up to the xiphoid process (deep water) or the iliac crest (shallow water), at 100, 110, 120, 130 step-per-minute (spm). Oxygen consumption (VO₂), heart rate (HR), blood lactate concentration, perceived exertion and step length were determined. Compared to deep water, walking in shallow water exhibited, at all intensities, significantly higher VO₂ (+13.5%, on average) and HR (+8.1%, on average) responses. Water depth did not influence lactate concentration, whereas perceived exertion was higher in shallow compared to deep water, solely at 120 (+40%) and 130 (+39.4%) spm. Average step length was reduced as the intensity increased (from 100 to 130 spm), irrespective of water depth. Expressed as a percentage of maximum, average VO₂ and HR were: 64–76% of peak VO₂ and 71–90% of maximum HR, respectively at both water depths. Accordingly, this form of exercise can be included in the “vigorous” range of exercise intensity, at any of the step frequencies used in this study.