Aerobic fitness and susceptibility to motion sickness

Susceptibility to motion sickness was evaluated in 29 males having high, moderate, and low levels of aerobic fitness. Subjects underwent Coriolis (cross-coupled) vestibular stimulation on a Stille-Werner rotator during a 10 min modification of the Brief Vestibular Disorientation Test (BVDT). Variables evaluated were: spin time before aborting (ST), heart rate (HR), respiratory rate (RR), mean skin temperature (Tsk), subject observation values (SV), and observation values (OV). Aerobic fitness and ST for the total population were inversely related (r = -0.506, p less than 0.01). Difference in ST was significant (F(2.26) = 6.67, p less than 0.01), with the high aerobic group demonstrating an earlier ST and greater SV than the low aerobic group (Student-Newman-Keuls; alpha = 0.05). Analysis of HR, RR, and Tsk between groups revealed limited differences. Based on these data, men with high aerobic fitness appear to have an increased susceptibility to motion sickness.     

Motion sickness susceptibility and aerobic fitness: a longitudinal study

A longitudinal study evaluated the susceptibility to motion sickness in initially unfit subjects before and after an endurance training program. Motion stimulation was provided by the Precision Angular Mover, in which the subject was tumbled head over heels about an Earth-horizontal axis at 20 cycles per minute in darkness. Maximal aerobic power and the blood lactate response to submaximal exercise were evaluated with cycle ergometry. The training program caused significant improvements in VO2max and endurance capacity, and a significant decrease in percent body fat. There was a significant (p less than 0.0125) increase in motion sickness susceptibility after the physical training, suggesting that increased physical fitness caused increased susceptibility to motion sickness in some individuals.     

Comparison of aerobic fitness and space motion sickness during the shuttle program

Space motion sickness (SMS) is an important problem for short duration space flight and 71% of STS crewmembers develop symptoms. The search for effective countermeasures and factors that correlate with sensitivity has been extensive. Recently, several investigators have linked aerobic fitness with motion sickness sensitivity in the 1-G or high-G environment. This paper compares the aerobic fitness of 125 Shuttle crewmembers with their SMS symptom category. Aerobic fitness data were obtained from the exercise tolerance test (ETT) conducted nearest the time of launch. SMS data were derived from the medical debrief summaries. Mean VO2max for crewmembers in four SMS categories (none, mild, moderate, severe) were 44.55, 44.08, 46.5, and 44.24 ml.kg-1.min-1, respectively. Scattergrams with linear regression analysis comparing aerobic fitness and SMS symptom classification are also presented. Correlation coefficients comparing SMS categories vs. aerobic fitness for men and women reveal no definite relationship between the two factors. Due to the subjective nature of the data, further studies are suggested to corroborate these findings.     

The susceptibility of rhesus monkeys to motion sickness

The susceptibility of rhesus monkeys to motion sickness was investigated using test conditions that are provocative for eliciting motion sickness in squirrel monkeys. Ten male rhesus monkeys and ten male Bolivian squirrel monkeys were rotated in the vertical axis at 150 degrees/s for a maximum duration of 45 min. Each animal was tested in two conditions, continuous rotation and intermittent rotation. None of the rhesus monkeys vomited during the motion tests but all of the squirrel monkeys did. Differences were observed between the species in the amount of activity that occurred during motion tests, with the squirrel monkeys being significantly more active than the rhesus monkeys. These results, while substantiating anecdotal reports of the resistance of rhesus monkeys to motion sickness, should be interpreted with caution because of the documented differences that exist between various species with regard to stimuli that are provocative for eliciting motion sickness.     

Gender differences in motion sickness history and susceptibility to optokinetic rotation-induced motion sickness

PURPOSE: The present study investigated gender differences in motion sickness history and susceptibility to optokinetic rotation-induced motion sickness. METHODS AND RESULTS: The study included two phases. In Phase 1, 485 subjects filled out a survey of previous incidence of motion sickness. Results indicated that women reported significantly greater incidence of feeling motion sickness than did men on buses, on trains, on planes, in cars, and on amusement rides before the age of 12 yr; and on buses, on trains, on planes, in boats, on ships, in cars, on amusement rides, and on swings between the ages of 12 and 25 yr. Women also reported significantly higher incidence of being actually sick than did men on buses before the age of 12 yr and on buses, on ships, and in cars between the ages of 12 and 25 yr. In Phase 2, each of the 47 subjects viewed an optokinetic rotating-drum for 16 min. Subjects' subjective symptoms of motion sickness (SSMS) were obtained during drum rotation. The results showed that there were no significant differences on SSMS scores between men and women. CONCLUSION: Although women reported greater incidence in motion sickness history, women did not differ from men in severity of symptoms of motion sickness while viewing a rotating optokinetic drum.     

心率变异性与运动病关系的研究

目的　探讨心率变异性与运动病的关系。方法　根据出海实习学员运动病的发生情况 ,将学员分为运动病组和对照组各 2 0人 ,采集安静状态下的 5 2 0次窦性心搏 ,应用心率变异时域、频域分析方法评价自主神经功能状态。结果　运动病组时域指标 RR间期平均值的标准差 (SDNN)、相邻 RR间期差值的均方根 (r MSSD)、相邻 RR间期相差大于 5 0 m s占总心动周期数的百分比 (PNN50 )、HRV指数(HRVI)和频域指标低频 (L F)、高频 (HF)、总功率谱密度 (TP)均显著高于对照组 (P<0 .0 5 )。 RR间期平均值 (MRR)、极低频 (VL F)、低频与高频的比值 (L F/ HF)在两组间差异无显著性 (P>0 .0 5 )。结论　自主神经功能状态对运动病的发生存在明显的影响 ,迷走神经张力过高与运动病的发生有密切关系。心率变异性检测可以作为运动病易感性重要的预测指标。     

幽门螺杆菌感染与晕动病的关系探讨

目的探讨幽门螺杆菌（HP）感染与晕动病发病的相关性。方法从参加海训人群中随机抽查300人，调查年龄、职别、疾病史、晕船症状及进行血清HP特异性抗体IgG（HP IgG）检测，根据调查结果进行分析。结果300人中，排除常见的眼耳疾病、饮食不当、休息不足、环境不良等诱发因素后，发生晕船者113例，晕船发生率37．7％。年龄、职别与晕船的发生无明显关系。HP IgG总的阳性率55．67％，晕船组阳性率70．80％（80／113），不晕船组阳性率46．50％（87／187），两组比较差异有统计学意义（P〈0．01）。HP IgG阳性者晕船发生率48．50％，HP IgG阴性者晕船发生率24．06％，两者比较差异有统计学意义（P〈0．01）。结论HP感染与晕动病的发生有一定相关性。     

Endocrine correlates of susceptibility to motion sickness

Motion sickness releases ACTH, epinephrine, and norepinephrine. We are interested in endocrine responses to motion sickness, in adaptive responses leading to the resolution of the syndrome, and in how antimotion-sickness drugs influence the endocrine responses. Susceptible or insusceptible subjects were administered antimotion-sickness drugs prior to stressful stimulation. Insusceptible subjects displayed more pronounced elevations of ACTH, epinephrine, and norepinephrine after stressful motion. Predrug levels of ACTH were higher in insusceptible subjects (p less than 0.01). Acute blockade of hormone responses to stressful motion or alteration of levels of ACTH by drugs was not correlated with individual susceptibility. No correlation was apparent between epinephrine and ACTH release. These endocrine differences may represent neurochemical markers for susceptibility to motion, stress, or general adaptability, and it may be that the chronic modulation of their levels might be more effective in preventing motion sickness than the acute blockade or stimulation of specific receptors.     

The effects of age and sex on susceptibility to motion sickness

BACKGROUND: The present investigation is concerned with the role of sex, age and experience in determining motion sickness susceptibility. HYPOTHESIS: Motion sickness susceptibility varies with sex and age, and may be related to the level of physical activity sustained by the individual. METHODS: Three surveys were conducted. The first included school age children (9-18 yr) and addressed motion experience and motion sickness on 13 forms of transport. The second questionnaire sought to determine whether these sex differences could be understood in terms of differential involvement in various forms of physical activity. The third survey addressed the role of age and sex effects in a college age population. RESULTS: The first study revealed significantly greater motion sickness for female as compared with male subjects on devices with which both groups were equivalent in terms of exposure history. The second study showed little relation between an individual's level of physical activity and susceptibility to motion sickness. The results of the third study were in essential agreement with the first survey and revealed no significant interactions between age and sex, suggesting that sex differences remain stable across this age range. CONCLUSION: Our conclusions regarding these surveys are that sex differences in motion sickness do not vary significantly with age and cannot be accounted for by differences in exposure to motion or physical activity. There was also little evidence for the notion that men are more reticent to report motion sickness.     

Effects of ethnicity and gender on motion sickness susceptibility

INTRODUCTION: Susceptibility to motion sickness (MS) is known to be affected by gender and ethnic origin, but whether gender and ethnicity are interacting is unknown. METHODS: We investigated MS development in healthy Caucasian subjects (n = 227), and in subjects of Chinese origin (n = 82). All subjects were exposed to nausea-inducing body rotations in a rotation chair, and rotated around the yaw axis for 5 x 1 min, while they were instructed to move their heads. Prior to rotation, subjects had to fill out a motion-sickness susceptibility questionnaire (MSSQ). Total rotation tolerance time (RT) was noted. Symptom ratings (SR) were performed at the beginning, and immediately after the end of each rotation, and 15 and 30 min later. RESULTS: The average RT was significantly higher in Caucasian (163 +/- 6 s) than in Chinese subjects (111 +/- 7 s) (F = 24.84, p < 0.0001). The adult MSSQ score was significantly lower in Caucasians (17.8 +/- 1.1) than in Chinese volunteers (24.2 +/- 2.1) (F = 6.05, p = 0.014). Maximal SR post rotation was similar in Chinese and Caucasian subjects. RT was highly predictable from the MSSQ scores, but separate for both genders. CONCLUSION: Susceptibility to MS is affected by both ethnic origin and by gender in a rather complex fashion. The most reliable prediction of RT can be based on the individual's history as assessed by the MSSQ.     

大鼠运动病敏感性与血浆皮质醇和促肾上腺皮质激素含量的关系

目的　探讨大鼠运动病敏感性与血浆皮质醇 (CORT)和促肾上腺皮质激素 (ACTH)含量的关系,进一步阐明体液因素在运动病发病中的作用。方法　采用大鼠条件性厌食症 (CTA)作为运动病模型和分组。84只雌性大鼠, 12只用于正常对照; 36只用于旋转刺激后大鼠血浆激素水平的测定(采用放射免疫分析法);另 36只用于前庭功能锻炼后大鼠血浆激素水平的测定。结果　大鼠运动病后血浆CORT和ACTH含量升高(P<0. 01),低敏感组[分别为(34. 51±6. 13)ng/ml和 (22. 42±3. 66)pg/ml]高于高敏感组[ (25. 74±4. 88)ng/ml和 (15. 88±3. 52)pg/ml] (P<0 01);功能锻炼后产生适应的高敏感组运动病大鼠血浆CORT、ACTH含量[ (29. 60±5. 99)ng/ml, (19. 83±6. 87)pg/ml]与低敏感组[ (34. 78±6. 37)ng/ml, (25. 37±6. 36)pg/ml]差异无统计学意义。结论　运动病与应激有关,运动病敏感性与血浆CORT、ACTH含量有关。     

Efficacy of phosphatidylcholine in the modulation of motion sickness susceptibility

This study evaluated the efficacy of pharmacological doses of phosphatidylcholine (lecithin) in the modulation of motion sickness induced by exposure to coriolis stimulation in a rotating chair. Subjects received daily dietary supplements of 25 grams of lecithin (90% phosphatidylcholine) and were tested for their susceptibility to motion sickness after 4 h, 2 d, and 21 d. A small but statistically significant increase in susceptibility (+ 15%) was noted 4 h after supplemental phosphatidylcholine, with four of nine subjects demonstrating a marked increase in susceptibility. We attributed this finding to choline's stimulatory action on cholinergic systems, an action which opposes that of the classical antimotion sickness drug scopolamine. Chronic lecithin loading revealed a trend towards reduced susceptibility, possibly indicating the occurrence of adaptive mechanisms such as receptor down-regulation. Withdrawal from lecithin loading, perhaps coupled with anticholinergic treatment, might prove to be a potent prophylactic regimen and ought to be tested.     

既往运动病易感性对科里奥利加速度耐受性的影响

目的观察既往运动病易感性水平对科里奥利加速度耐受性是否有影响。方法采用运动病易感量表筛选58名不同运动病易感的健康志愿者,采用垂直轴旋转刺激(每秒钟60°顺时针旋转)使身体旋转,以恶心评定量表、恶心问卷和旋转耐受时间为指标观察不同易感者的症状程度和旋转耐受时间的差异。结果既往运动病易感组童年期运动病易感得分、成年期运动病易感得分、运动病易感总分均高于非易感组(P<0.01)。运动病易感组和非易感组旋转耐受时间差异无显著性意义。易感组旋转前、旋转后即刻、旋转后15 min、30 min恶心评定量表得分均高于非易感组,差异有显著性意义。易感组恶心问卷总分、消化道不适得分、情绪困扰得分高于非易感组,差异有非常显著性意义(P<0.01)。既往运动病易感性与旋转耐受时间不相关;与旋转前、旋转后即刻、旋转后15 min3、0 min恶心评定量表得分、恶心问卷总分、躯体不适得分、消化道不适得分和情绪困扰得分呈显著相关。结论既往运动病易感性影响科里奥利加速度耐受性,可作为试验性运动病的预测指标。     

Some influences of vision on susceptibility to motion sickness.

Two experiments were performed to evaluate the influence of vision on susceptibility to motion sickness during exposure to constant patterns of vestibular stimulation. The motion profile involved accelerating subjects at 20 degrees/s2 to 300 degrees/s, maintaining them at that constant velocity for 30 s, and decelerating them to a rapid stop in about 1.5 s. The number of stops tolerated by a subject before reaching the motion sickness endpoint served as his score. In Experiment 1, subjects were tested twice with their eyes open and twice with their eyes blindfolded. They tolerated fewer sudden stops when permitted sight of the experimental chamber. In Experiment 2, the effect of having the eyes-open or closed at different stages of the motion profile was evaluated. Having the eyes open during any stage of the test was more stressful than having the eyes closed, but this was especially true during the sudden stops. The findings are discussed in terms of their general implications for understanding a) situations in which vision alone elicits symptoms of motion sickness, and b) situations involving vestibular stimulation where vision heightens susceptibility.     

An association between aerobic fitness and lung closing volume

This study was performed to determine whether an association exists between relative aerobic fitness (fitness index) and lung closing volume (CV). The subject population consisted of 100 healthy nonsmoking adults (50 males and 50 females) divided equally into five age groups; 20-29, 30-39, 40-49, 50-59, and over 60 years. Each subject underwent four to six closing volume and forced vital capacity (FVC) tests followed by a modified Balke maximal oxygen uptake test on a motor-driven treadmill with a constant treadmill speed. Relative VO2 maximum (VO2 max, mlO2 X kg-1 X min-1) was determined from the exercise test and was used to define subject rank on the fitness index. CV, as a % of slow vital capacity (SVC), had a negative linear correlation (r = -0.53, P less than 0.05) with the fitness index. Slope of phase III (%N2/L) and FEV1/FVC (forced expired volume in 1 s as a % of forced vital capacity) also had significant correlation coefficients (r = -0.31, r = 0.24, respectively; both P less than 0.05) with the fitness index. The correlation coefficients, with age partialled from the relationships, between FVC/body weight (kg) and VO2 max were r = 0.59 for females and r = 0.43 for males (P less than 0.05, both groups). We hypothesize that the effects of aerobic fitness on lung function may be the result of changes in autonomic nervous system activity and may represent a situation where a high level of aerobic fitness affects the aging process of the lung beta-adrenergic nervous system.     

The relationship between aerobic fitness and recovery from high intensity intermittent exercise

A strong relationship between aerobic fitness and the aerobic response to repeated bouts of high intensity exercise has been established, suggesting that aerobic fitness is important in determining the magnitude of the oxidative response. The elevation of exercise oxygen consumption (VO2) is at least partially responsible for the larger fast component of excess post-exercise oxygen consumption (EPOC) seen in endurance-trained athletes following intense intermittent exercise. Replenishment of phosphocreatine (PCr) has been linked to both fast EPOC and power recovery in repeated efforts. Although 31P magnetic resonance spectroscopy studies appear to support a relationship between endurance training and PCr recovery following both submaximal work and repeated bouts of moderate intensity exercise, PCr resynthesis following single bouts of high intensity effort does not always correlate well with maximal oxygen consumption (VO2max). It appears that intense exercise involving larger muscle mass displays a stronger relationship between VO2max and PCr resynthesis than does intense exercise utilising small muscle mass. A strong relationship between power recovery and endurance fitness, as measured by the percentage VO2max corresponding to a blood lactate concentration of 4 mmol/L, has been demonstrated. The results from most studies examining power recovery and VO2max seem to suggest that endurance training and/or a higher VO2max results in superior power recovery across repeated bouts of high intensity intermittent exercise. Some studies have supported an association between aerobic fitness and lactate removal following high intensity exercise, whereas others have failed to confirm an association. Unfortunately, all studies have relied on measurements of blood lactate to reflect muscle lactate clearance, and different mathematical methods have been used for assessing blood lactate clearance, which may compromise conclusions on lactate removal. In summary, the literature suggests that aerobic fitness enhances recovery from high intensity intermittent exercise through increased aerobic response, improved lactate removal and enhanced PCr regeneration.     

Estimated body rotation as a predictor of motion sickness susceptibility.

We rotated 36 blindfolded subjects in yaw between 30 degrees and 135 degrees and asked them to estimate the angular displacement they had experienced. An index of a subject's "receptivity" was obtained by calculating the slope of the line relating perceived to actual displacement; his susceptibility to motion sickness was determined by a questionnaire. The product moment correlation between these two measures was not significant, a result which conflicts with the receptivity hypothesis. It is suggested that "adaptability" rather than "receptivity" may be the more impotant determinant of susceptibility to motion sickness.