Sampling period determination for heart rate logging under an exercise regimen

Abstract

Using a mathematical procedure, we determine appropriate sampling rates for logging heart rate, at a variety of exercise intensities. The mathematical procedure involves correlating exercise and heart rate data to determine a dynamical mathematical model, from which the frequency response of the relationship between exercise intensity and heart rate can be determined. The sampling rate is then straightforwardly deduced by making appropriate measurements on the frequency response curve. We show how careful consideration needs to be given to the choice of dynamical model structure and the work regimen, so that consistent and convincing conclusions can be drawn. We demonstrate that the dynamics of the work-rate/heart-rate system are dependent on the nominal work/heart rate, but a 5-s sampling period, as used in many commercial heart rate monitors, appears to be adequate, especially when some averaging is performed before logging.     

肥胖大学生亚健康症状与课余体育锻炼的关系研究

运用问卷调查法、数理统计法对肥胖大学生的亚健康症状与课余体育锻炼相关因素进行调查研究。结果表明：大学生的肥胖率为2.06%,男大学生的肥胖率显著高于女大学生,肥胖女大学生的亚健康症状发生率明显高于肥胖男大学生,51.18%的具有亚健康症状的肥胖大学生经常参加课余体育锻炼,锻炼频度和锻炼强度是影响具有亚健康症状的肥胖大学生课余体育锻炼效果的主要因素,每周锻炼3次及其以上、每次锻炼60min以上、锻炼强度在最大心率的70%以上的肥胖大学生的亚健康症状发生率显著下降。     

优秀耐力性运动员心肺功能某些指标的三维动态数学模型及数理关系的研究

本研究从运动医学和医用数学的角度,探讨了优秀耐力性运动员运动过程中,心肺功能吸氧量等6项指标随心率和呼吸频率自变量而变化的三维动态数学模型,并用三维模型曲面图和空间轨迹图直观地描述和表达了模型较为复杂、抽象的动态数理关系,达到了在同一动态数量关系体系中,只要获得自变量指标的动态变化数据输入,即可求出其他相关指标的变化数据之目的,从而为你能训练过程中的实时医学监控提供生物学指标体系和数据源,为运动训练的实时临控和心肺机能评定提供了一个方法学上的参考。     

Modeling and predicting heart rate dynamics across a broad range of transient exercise intensities during cycling

Prior studies have investigated heart rate dynamics from a variety of perspectives, but are often inadequate for predicting heart rate responses across a broad range of transient exercise intensities. The aim of this study was to develop a nonlinear model to describe the heart rate response of an individual during cycling and to investigate whether heart rate is more accurately predicted by a combination of power output and cadence than by power output alone. The proposed model can account for the transient fluctuations of an individual’s heart rate while they participate in exercise that varies in intensity. The participants for this study each performed a fifty minute bout of cycling on an electric-braked cycle ergometer in the laboratory. The testing protocol for the cycling bout was designed to challenge the predictive capabilities of the model and the participants therefore abruptly changed their power outputs and cadences throughout the tests, which resulted in significant transient fluctuations in their heart rate responses. Due to the nonlinear nature of the proposed heart rate model, a heuristic algorithm was developed to perform the parameter estimation. The model predictions for heart rate matched very well with the experimental heart rate responses for each of the participants, especially when considering the challenges inherent to predicting abrupt transient behavior in the heart rate response. Model comparisons also indicated that heart rate is more accurately predicted by a combination of power output and cadence than by power output alone.     

Executive functioning during prolonged exercise: a fatigue-based neurocognitive perspective

ABSTRACT

Despite emotional, technical and endurance implications for athletes’ performance, a consensus has yet to be reached to explain the impairment of executive functioning during exercise. In particular, recent research challenges the original assumption of a linear dose–response effect of exercise intensity on cerebral physiology and executive functioning. We propose a fatigue-based neurocognitive perspective of executive functioning during prolonged exercise, suggesting that top-down (cognitive and physical efforts) and bottom-up processes (body sensations) act in parallel of arousing mechanisms to determine cognitive outcomes. In this perspective, executive functioning during prolonged exercise would be dynamical rather than steady (i.e. positively then negatively impacted by exercise) and would be to analyse in regards of exercise termination rather than of exercise intensity.     

冠心病康复中有氧运动强度设定方法的比较及展望

运动康复是冠心病康复的核心内容,其中有氧运动是基础。冠心病常规运动康复程序是对患者开展康复评估及危险分层后,给予区分危险度后的个体化康复运动,运动处方的制定是关键。如何准确客观地确定有氧运动强度是冠心病康复运动处方的重要环节。本文综述了不同冠心病康复有氧运动强度设定方法的优势、局限性及其临床应用状况,以期为冠心病患者进行有氧运动提供安全有效的强度设定方法,促进心脏康复在国内的发展与推广。     

The Effect of Bicycle Ergometer Exercise at Varying Intensities on the Heart Rate,EMG and Mood State Responses to a Mental Arithmetic Stressor

Abstract

The purpose of this study was to examine the effect of bicycle ergometer exercise at varying metabolic intensities upon the heart rate, electromyographic (EMG), and mood state responses to a timed mental arithmetic stressor. Twelve males participated in four experimental conditions: three exercise trials consisting of workloads of 40%, 55%, and 70% of physical work capacity, and an attentional control condition. Daily test protocol involved the following time sequence: habituation, baseline, exercise or control condition (presented in a counterbalanced order), recovery, mental arithmetic, and completion of mood state questionnaire. Results indicated no differential response to the mental arithmetic stressor across the four conditions for the 12 subjects for heart rate, EMG activity, or mood state. Thus, 15 min of exercise at 40%, 55%, and 70% of physical work capacity proved to be no different from an attentional control condition in influencing the physiological and psychological responses to the mental arithmetic stressor.     

Exercise intensity and metabolic response in singles tennis

The aim of this study was to determine exercise intensity and metabolic response during singles tennis play. Techniques for assessment of exercise intensity were studied on-court and in the laboratory. The on-court study required eight State-level tennis players to complete a competitive singles tennis match. During the laboratory study, a separate group of seven male subjects performed an intermittent and a continuous treadmill run. During tennis play, heart rate (HR) and relative exercise intensity (72 +/- 1.9% VO2max; estimated from measurement of heart rate) remained constant (83.4 +/- 0.9% HRmax; mean +/- s(x)) after the second change of end. The peak value for estimated play intensity (1.25 +/- 0.11 steps x s(-1); from video analysis) occurred after the fourth change of end (P< 0.005). Plasma lactate concentration, measured at rest and at the change of ends, increased 175% from 2.13 +/- 0.32 mmol x l(-1) at rest to a peak 5.86 +/- 1.33 mmol x l(-1) after the sixth change of end (P < 0.001). A linear regression model, which included significant terms for %HRmax (P< 0.001), estimated play intensity (P < 0.001) and subject (P < 0.00), as well as a %HRmax subject interaction (P < 0.05), accounted for 82% of the variation in plasma lactate concentration. During intermittent laboratory treadmill running, % VO2peak estimated from heart rate was 17% higher than the value derived from the measured VO2 (79.7 +/- 2.2% and 69.0 +/- 2.5% VO2peak respectively; P< 0.001). The %VO2peak was estimated with reasonable accuracy during continuous treadmill running (5% error). We conclude that changes in exercise intensity based on measurements of heart rate and a time-motion analysis of court movement patterns explain the variation in lactate concentration observed during singles tennis, and that measuring heart rate during play, in association with preliminary fitness tests to estimate VO2, will overestimate the aerobic response.     

An Analysis of Heart Rateesponse to Exercise

Abstract

Heart rate response to exercise and recovery after exercise were studied analytically on the basis that any energy extracted from a muscle must ultimately be supplied by oxidation. Any discrepancy between oxygen supply rate and equivalent oxygen consumption rate was assumed to be made up by utilizing a finite reserve; thus allowing supply to lag consumption at the onset of exercise. Heart rate was assumed and experimentally demonstrated to be linearly related to oxygen supply rate during both steady-state and the transition period after exercise starts or stops. During recovery the withdrawals from reserves are repaid as heart rate returns to normal. Consideration of these factors resulted in an exponential heart rate response equation which closely agreed with observations. Coefficients, evaluated from experimental data, gave average time constants of 1.2 to 1.7 sec. with recovery being slower than response to exercise. Integration of this equation over the exercise range gave an estimate of the deficiency of supply as compared to consumption. A similar integration over the recovery phase indicated that in this range, supply exceeded consumption by at least as much as it was deficient during the exercise phase.     

大负荷运动状态下男运动员部分生理、心理指标测试分析

采用台阶实验法，测试大负荷运动状态下男运动员的心率、肺活量、闪烁频率、平衡能力等生理、心理指标。结果表明：40cm高、每min上下40次台阶实验中，被试心率均可达180bs／min以上，该实验可作为研究大负荷运动状态下测试生理、心理机能的方法；在大负荷运动状态下，运动后即刻心理机能提高；运动后即刻与休息5min后的心理指标比较显示，心理机能可能存在延迟下降的现象。     

对西安市中年女子水中健身的探讨

采用文献资料、身体成份测试、人体测量、数理统计以及实验研究等方法，对西安市20名成年女性进行为期3个月的水中有氧健身训练。结果表明：练习者在运动前后其身体体重没有明显变化，但肌肉重量增加．身体脂肪比率、身体围度指标降低，安静时心率及体重指数(BMI)都有不同程度的下降。结论：水中有氧健身运动对发展成年女性体质具有良好促进作用。     

Heart Rate Variability

The purpose of the present study was to investigate the influence of two exercise intensities (moderate and severe) on heart rate variability (HRV) response in 16 runners 1 hr prior to (-1 hr) and at +1 hr, +24 hr, +48 hr, and +72 hr following each exercise session. Time domain indexes and a high frequency component showed a significant decrease (p < .001) between -1 hr and +1 hr for severe intensity. The low frequency component in normalized units significantly increased (p <.01) for severe intensity at +1 hr. Only severe exercise elicited a change in HRV outcomes postexercise, resulting in a reduction in the parasympathetic influence on the heart at +1 hr; however, values returned to baseline levels by +24 hr.     

Exercise intensity and metabolic response in singles tennis

The aim of this study was to determine exercise intensity and metabolic response during singles tennis play. Techniques for assessment of exercise intensity were studied on-court and in the laboratory. The on-court study required eight State-level tennis players to complete a competitive singles tennis match. During the laboratory study, a separate group of seven male subjects performed an intermittent and a continuous treadmill run. During tennis play, heart rate (HR) and relative exercise intensity (72 ± 1.9% V O 2m ax ; estimated from measurement of heart rate) remained constant (83.4 ± 0.9% HR m ax ; mean s x ) after the second change of end. The peak value for estimated play intensity (1.25 ± 0.11 steps . s -1 ; from video analysis) occurred after the fourth change of end (P < 0.005). Plasma lactate concentration, measured at rest and at the change of ends, increased 175% from 2.13 ± 0.32 mmol . l -1 at rest to a peak 5.86 ± 1.33 mmol . l -1 after the sixth change of end (P < 0.001). A linear regression model, which included significant terms for %HR m ax (P < 0.001) and subject (P < 0.001), as well as a %HR max subject interaction (P < 0.05), accounted for 82% of the variation in plasma lactate concentration. During intermittent laboratory treadmill running, % V O 2peak estimated from heart rate was 17% higher than the value derived from the measured V O 2 (79.7 ± 2.2% and 69.0 ± 2.5% V O 2peak respectively; P < 0.001). The % V O 2peak was estimated with reasonable accuracy during continuous treadmill running (5% error). We conclude that changes in exercise intensity based on measurements of heart rate and a time-motion analysis of court movement patterns explain the variation in lactate concentration observed during singles tennis, and that measuring heart rate during play, in association with preliminary fitness tests to estimate V O 2 , will overestimate the aerobic response. (P < 0.001), estimated play intensity     

有氧健身操对增强中年女性心肺功能的作用

通过对80名中年女性实施12周有氧健身操练习，探讨有氧健身操对提高中年女性心肺功能的作用，结果发现有氧健身操可降低安静心率与血压，提高台阶实验指数，增加肺活量，是一种有效提高中年女性心肺功能的健身方法。     

第八届民族传统健身操运动强度的研究

为了解第八届全国少数民族健身操的运动强度,在比赛前一天的热身赛中,抽取11个参赛队的运动员共51人作为研究对象。通过测试运动员安静、运动后即刻、运动后4、5、6分钟的脉搏来评定运动员的身体机能,运动强度和运动后的恢复情况。研究结果显示：成年人安静心率63.7±6.8次/分钟,运动后即刻心率达到164.8±24.97次/分钟,强度达到中高强度,运动后6分钟心率为75.5±20.8次/分钟,基本恢复安静,心率比安静时高,可能与当时运动现场的环境有关。少年对主要是指山东队,其运动员的安静心率为68.2±3.6次/分钟,运动后即刻心率达到120±29.4次/分钟,强度属于中低强度,运动后6分钟心率为70.5±4.7次/分钟,心率基本恢复正常。     

有氧健身操对中年女性心肺功能的影响

通过对60名中年女性实施16周有氧健身操练习，探讨有氧健身操对提高中年女性心肺功能的作用，结果发现有氧健身操可降低安静心率与血压、提高台阶实验指数、增加肺活量，是一种有效提高中年女性心肺功能的健身方法。     

Effects of cigarette smoking on cardiac autonomic function during dynamic exercise

The purpose of this study was to investigate the acute effect of cigarette smoking on cardiac autonomic function in young adult smokers during dynamic exercise. Fourteen healthy young smokers (21.4 ± 3.4 years) performed peak and submaximal exercise protocols under control and smoking conditions. Resting and submaximal beat-to-beat R-R series were recorded and spectrally decomposed using the fast Fourier transformation. Smoking resulted in a significant decrease in work time, VO(2peak) and peak O(2) pulse (P < 0.05). Heart rate increased at rest and during submaximal exercise after smoking (P < 0.05). The raw high frequency and low frequency power were significantly reduced by smoking, both at rest and during exercise (P < 0.05). The low to high frequency ratio was higher after smoking (P < 0.05). The normalised low frequency power was also significantly increased by smoking, but only at rest (P < 0.05). These data demonstrate that the tachycardic effect elicited by smoking is accompanied by acute changes in heart rate spectral components both at rest and during exercise. Therefore, the cardiac autonomic control is altered by smoking not only at rest, but also during exercise, resulting in reduced vagal modulation and increased sympathetic dominance.     

A comparison of methods for estimating oxygen uptake during intermittent exercise

Sixteen female games players completed 15 min of intermittent exercise on a treadmill. The speed and incline of the treadmill were varied to elicit a similar heart rate response to that found during women's hockey match‐play. The mean heart rate response was 169 ± 8 beats min^‐1 and the mean work:rest ratio was 1:1.7. Oxygen uptake was estimated by applying the oxygen cost determined from an individual's heart rate‐oxygen uptake regression equation to the average heart rate each 5 s during the intermittent exercise. A second esimation of oxygen uptake was made from a time‐motion analysis by assigning a specific oxygen cost to each discrete movement during the intermittent exercise protocol. The true oxygen cost was calculated from the analysis of the expired gas. The heart rate analysis overestimated the true cost by a mean of 4.3 ± 5.3% (0.09 ± 0.11 1 min^‐1), and the time‐motion analysis underestimated the true value by a mean of 15.7 ± 6.3% (0.34 ± 0.15 1 min^‐1). There was a significant difference (P < 0.01) between the true value and both the estimates. It was concluded that heart rate analysis gives a much better indication of oxygen uptake during intermittent activity than time‐motion analysis.     

Eccentric exercise-induced muscle damage dissociates the lactate and gas exchange thresholds

We tested the hypothesis that exercise-induced muscle damage would increase the ventilatory (V(E)) response to incremental/ramp cycle exercise (lower the gas exchange threshold) without altering the blood lactate profile, thereby dissociating the gas exchange and lactate thresholds. Ten physically active men completed maximal incremental cycle tests before (pre) and 48 h after (post) performing eccentric exercise comprising 100 squats. Pulmonary gas exchange was measured breath-by-breath and fingertip blood sampled at 1-min intervals for determination of blood lactate concentration. The gas exchange threshold occurred at a lower work rate (pre: 136 ± 27 W; post: 105 ± 19 W; P < 0.05) and oxygen uptake (VO(2)) (pre: 1.58 ± 0.26 litres · min(-1); post: 1.41 ± 0.14 litres · min(-1); P < 0.05) after eccentric exercise. However, the lactate threshold occurred at a similar work rate (pre: 161 ± 19 W; post: 158 ± 22 W; P > 0.05) and VO(2) (pre: 1.90 ± 0.20 litres · min(-1); post: 1.88 ± 0.15 litres · min(-1); P > 0.05) after eccentric exercise. These findings demonstrate that exercise-induced muscle damage dissociates the V(E) response to incremental/ramp exercise from the blood lactate response, indicating that V(E) may be controlled by additional or altered neurogenic stimuli following eccentric exercise. Thus, due consideration of prior eccentric exercise should be made when using the gas exchange threshold to provide a non-invasive estimation of the lactate threshold.     

小学生50米×8往返跑心率变化规律研究

为确定小学生耐力锻炼安全有效的负荷强度,采用试验法、数理统计法,以50米×8往返跑过程中男女学生心率强度和变化规律为研究内容,抽取厦门市金尚小学五年级72名为观察对象,采用ON-rhythm 410 progress心率表,按照50米×8往返跑测试成绩合格、良好、优秀三个等级进行分组测试,结果显示;学生往返跑第三次时平均心率已经达到181次/分。心率在190~200次/分的强度下要持续1分30秒左右。研究认为小学生50米×8往返跑的练习应循序渐进的原则,最高心率维持时间不宜超过1分30秒的时间范围。