Higher Degree Of Physical Activity Research Articles

Venous disorders as an occupational disease - a systematic review on epidemiology, pathophysiology, and modification strategies.

Forced postures are common in the workplace. Work in the primary economic sector is characterised by a high degree of physical activity and movement; however, activities in the secondary and tertiary sectors commonly require workers to stand or sit. An expansion of the tertiary sector in recent decades has meant that people in industrialised and emerging economies primarily sit or stand at work. The aim of the systematic review was to identify occupational factors relating to the presence of chronic venous disease (CVD), to place these in the context of developments in the workplace, and to determine whether measures are in place to prevent CVD. We performed a systematic literature review to analyse studies assessing work-related risk factors for CVD. We searched for publications in the PubMed database, the clinic library of BG Hospital Bergmannstrost Halle, and the registry of the German Statutory Accident Insurance. Using occupation-specific keyword combinations, we identified 27,522 publications. The publications underwent an automatic and manual filtering process according to the PRISMA guidelines and 81 publications qualified for the review. Ultimately 25 studies were included in the systematic review. All of the subjects of the studies worked in the secondary and tertiary sectors. No studies looked at the relationship between venous disorders and primary sector occupations. Standing at work for more than four hours a day, repeated heavy lifting, and cumulative time working in a sitting or standing position are risk factors for the development of CVD. Sitting is less of a risk factor than standing or walking. Occupational history and the patient's activity profile are important diagnostic tools which can help confirm a diagnosis and justify treatment when findings are inconsistent. Compression therapy is the primary form of secondary and tertiary prevention. There continues to be a lack of primary preventive measures related to workplace design.

Degree of Physical Activity in University Teachers Before and During the COVID-19 Pandemic

The objective of this work was to analyze the degree of physical activity of university teachers before and during the Covid-19 pandemic, this in the context of social isolation. The present study adopts a quantitative and cross-sectional approach. The sample was determined randomly, made up of 129 university professors from the Faculty of Physical Culture Sciences of the Autonomous University of Chihuahua, aged between 18 and 74 years. The results show that 50.39% of teachers before the pandemic maintained a high degree of physical activity, while during confinement they presented a lower degree of physical activity, decreasing to only 39.53%. The Covid-19 not only wreaked havoc on health, but also negative effects in the psychological, emotional and social sphere of people, as well as havoc in the practice of physical activity, modifying healthy lifestyles and leaving possible effects for the consequent physical health.

Degree of Physical Activity in University Teachers Before and During the COVID-19 Pandemic

The objective of this work was to analyze the degree of physical activity of university teachers before and during the Covid-19 pandemic, this in the context of social isolation. The present study adopts a quantitative and cross-sectional approach. The sample was determined randomly, made up of 129 university professors from the Faculty of Physical Culture Sciences of the Autonomous University of Chihuahua, aged between 18 and 74 years. The results show that 50.39% of teachers before the pandemic maintained a high degree of physical activity, while during confinement they presented a lower degree of physical activity, decreasing to only 39.53%. The Covid-19 not only wreaked havoc on health, but also negative effects in the psychological, emotional and social sphere of people, as well as havoc in the practice of physical activity, modifying healthy lifestyles and leaving possible effects for the consequent physical health.

Causal effects of physical activity or sedentary behaviors on kidney function: an integrated population-scale observational analysis and Mendelian randomization study.

An investigation into the causality of the effects of physical activity and specific sedentary activities on kidney function in the general population is warranted. In this observational cohort study, first, the clinical associations of the prevalence of stages 3-5 chronic kidney disease (CKD) and the estimated glomerular filtration rate (eGFR) with physical activity, determined by self-report or objective wrist-band accelerometer results, and sedentary activities (watching television, using a computer and driving) were investigated in 329 758 UK Biobank participants. To assess causality, a two-sample Mendelian randomization (MR) analysis was performed to investigate the associations of a genetic predisposition to physical activity and a sedentary lifestyle with the risk of kidney function impairment in an independent CKDGen genome-wide association study (N = 567 460). The findings were replicated with the 321 024 UK White British Biobank participants in the allele-score-based one-sample MR. A higher degree of self-reported or accelerometer-determined moderate-to-vigorous physical activity was associated with a higher eGFR, while a longer time spent watching television was significantly associated with a lower eGFR and a higher prevalence of CKD. The two-sample MR demonstrated that the genetic predisposition to a higher degree of physical activity was associated with a lower risk of CKD and a higher eGFR, while the genetically predicted television watching duration was associated with a higher risk of CKD and a lower eGFR. The other sedentary behaviors yielded inconsistent results. The findings were similarly replicated in the one-sample MR. Physical activity and television watching causally affect kidney function in the general population.

Association between physical activity and KNEE osteoarthritis features on magnetic resonance imaging in individuals without knee osteoarthritis: a systematic review

Purpose: As there are concerns that a high degree of physical activity (PA) may increase the risk of knee osteoarthritis (OA) development, epidemiological studies have been undertaken to examine whether PA has effects on structural changes in the knee. Several studies used magnetic resonance imaging (MRI) to capture OA features (e.g. cartilage defects and meniscal pathologies) in early onset of disease as the development of OA features on radiography usually takes years. Therefore, the aim of this study was to systematically review all studies that evaluated the association between PA levels and knee OA features on MRI, among subjects without knee OA.

Abstract 14085: Population Health Delivery: A Community Health Needs Assessment Related to Physical Activity and Exercise

Introduction: A community health needs assessment asks members to measure the health of their community by prioritizing problems and identifying the needs. Methods: There are 10 counties in the Cedar Valley Area of Northeast Iowa, USA. Healthcare providers and allied service organizations came together as partners to write online survey to identify the community health needs of Cedar Valley residents. The online survey for residents was posted from March 1-May 15, 2019 and drew 1,554 unique responses. The online Survey Monkey for residents was supplemented by paper surveys distributed to and collected from members of minority church congregations. Responses were tabulated and analyzed. Once the initial responses arrived, the partners reached out to gather additional responses from minority populations to help match the overall return to the market profile. The resident survey was extended 45 days past its original deadline to ensure additional returns. This report focuses on physical inactivity and exercise part of the multi question survey. Results: For the question of risky adult behavior, 45% of the residents identified physical inactivity. For question of what healthy behaviors would you like to start or do more often to improve your health, 77% of the residents identified more exercise. For the question of what prevents you from doing the healthy behavior, 63% identified lack of motivation, 61% identified not enough time. But only 5% said that they were not aware of the healthy options. For the question of what would help you or your family members to start or maintain a healthier lifestyle, 58% identified more affordable facilities, 36% identified employee wellness programs, 32% identified community exercise programs and 17% identified school wellness programs. Conclusion: These results indicate that there is clear awareness in this community that physical inactivity is a risky adult behavior and 95% of the population was aware of exercise as a healthy option. The results also identified specific perceived needs. To achieve high degree of physical activity and exercise and to maintain population health, more efforts need to be focused on wellness programs to improve the motivation and make available affordable facilities.

The Role of Raw Beetroot in Enhancing Amateur Exercise Performance

Abstract Objectives In a time when prolonged sitting is an important part of people's daily busy lives, any easy solution contributing to enhancing general stamina and amateur fitness physical performance in a safe and inexpensive way can be always attractive. Red beetroot (Beta vulgaris rubra) and its constituents known as having important health benefits in many various areas, has become increasingly popular in the arena of exercise performance, mainly due to high concentrations of nitrate. Previous studies done in different types of professional athletes - most of them using beetroot either as juice or powder - proved its clear efficiency in increasing the physical performance both in terms of speed and endurance. Could beetroot help as well other kind of individuals who due to their busy professions, though willing to stay fit, have less access to higher degree of physical activity? The aim of this preliminary study was to evaluate in which measure beetroot can be used by amateurs willing to improve their general stamina and stay physically fit. Methods The benefits of plant compounds contained in beetroot - such as betanin, vulgaxanthin and inorganic nitrates - known to help increase the blood oxygenation, muscle strength, and mental acuity - were evaluated among healthy adults (age 25–60) during a short sessions of simple physical activity, repeated for 7–10 days. To compare, a single serving of 100 g raw beetroot was taken 1–2 hours prior the activity and evaluations were made. An intelligent health bracelet was used to measure some of the common vital parameters. Results Though modest, an average increase in the daily physical performance of 6.17%, a general increase of 31% at the end of the period of evaluation, and most of all, a visible increase in general stamina, shows the great potential beetroot has as ergogenic aid in moderate exercise. Conclusions Though raw beetroot may provide modest performance enhancement, the observations show to be encouraging and more research would be definitely needed, in a larger number of individuals, on a more diverse types of physical activities, and using more professional evaluating tools, in order to clarify the mechanism of action and eventually the proper dosing patterns. Funding Sources None.

More habitual physical activity is linked to the use of specific, more adaptive cognitive reappraisal strategies in dealing with stressful events.

Physical activity may improve stress resilience and well‐being. However, specific links to individuals' coping abilities with stressful events are sparse. This study tested whether individuals reporting more physical activity in daily life showed a higher capacity for cognitive reappraisal in dealing with potential stressors. Ninety‐eight participants reported their regular physical activity in the Freiburger Questionnaire on Physical Activity and completed a maximum performance test of their inventiveness in generating reappraisals for situations depicting real‐life stressors. The latter provides scores for overall cognitive reappraisal capacity (quantity of ideas) and preference for specific cognitive reappraisal strategies (quality of ideas; positive reinterpretation; problem‐oriented, de‐emphasizing reappraisals). Additionally, participants' anxious and depressive dispositions and general creative abilities were assessed. Results showed no association between time spent on physical activities per week and total quantity of generated reappraisal ideas. However, a higher degree of physical activity was specifically linked to a greater relative preference for the reappraisal strategy of positive reinterpretation. Opposite associations emerged for the strategy of de‐emphasizing reappraisals. The findings support the notion of more adaptive cognitive reappraisal use in more physically active individuals and may advance research on interrelationships between physical activity and cognitive and affective functions implicated in stress management.

730-P: Inverse Association between Physical Activity and Blood Glucose Is Independent of Sex, Menopause, and Family History of Diabetes

Objectives: Exercise training is critical to the prevention, treatment and management of diabetes and prediabetes. The present study was to investigate the association between physical activity and blood glucose, as well as the influence of sex, menopause status, and family history of diabetes. Methods: Subjects with normal weight (body mass index ≥ 18.5 and < 25) were selected from REACTION study, and divided into inactive (moderate-to-vigorous-intensity physical activity [MVPA] < 30 min/week), low-degree (MVPA ≥ 30 and ≤ 420 min/week), and high-degree (MVPA > 420 min/week) active groups. Results: A total of 2601 individuals with an average age of 57.85 ± 8.39 years were enrolled. Multivariate ANOVA uncovered that after adjustment for sex and menopause status and first-degree family history of diabetes respectively, fasting plasma glucose (FPG), 2-hour plasma glucose (2hPG), and glycated hemoglobin A1c (HbA1c) decreased through inactive, low-degree and high-degree active groups (all P for trend < 0.05). The association of blood glucose indexes with physical activity was independent of this association with sex and menopause status and family history of diabetes, respectively. Multivariate linear regression analyses showed that MVPA was an independent factor associated negatively with FPG (standardized β = -0.057, P = 0.003), 2hPG (standardized β = -0.094, P < 0.001), and HbA1c (standardized β = -0.071, P < 0.001), respectively. Conclusions: Higher degree of physical activity was associated with lower blood glucose regardless of sex, menopause status, and family history of diabetes. MVPA is a negative factor associated with blood glucose independently. Physical activity with adequate time and intensity is strongly recommended to individuals with susceptibility to diabetes but without overweight/obesity. Disclosure X. Hu: None. X. Gu: None. Funding National Key Research and Development Program of China (2016YFC1305202); Wenzhou Science & Technology Bureau (Y20170047)

Inverse association between physical activity and blood glucose is independent of sex, menopause status and first-degree family history of diabetes.

Aims/IntroductionExercise training is a recognized strategy central to the prevention, treatment, and management of diabetes and prediabetes. The aim of the present study was to investigate the association between physical activity and blood glucose, as well as the influence of sex, menopause status and family history of diabetes.Materials and MethodsParticipants with normal weight were selected from Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal Study, and divided into inactive (moderate‐to‐vigorous‐intensity physical activity [MVPA] <30 min/week), low‐degree (MVPA ≥30 and ≤420 min/week) and high‐degree (MVPA >420 min/week) activity groups.ResultsA total of 2,601 individuals with an average age of 57.85 ± 8.39 years were enrolled. Multivariate anova uncovered that after adjustment for sex and menopause status, and family history of diabetes, respectively, fasting plasma glucose, 2‐h plasma glucose and glycated hemoglobin A1c decreased through inactive, low‐degree and high‐degree activity groups (all P for trend <0.05). The association of blood glucose indexes with physical activity was independent of this association with sex and menopause status, and first‐degree family history of diabetes, respectively. Multivariate linear regression analyses showed that MVPA was an independent factor associated negatively with fasting plasma glucose, 2‐h plasma glucose and glycated hemoglobin A1c, respectively (all P < 0.01).ConclusionsA higher degree of physical activity was associated with lower blood glucose regardless of sex, menopause status and first‐degree family history of diabetes. MVPA is a negative factor associated with blood glucose independently. Physical activity of adequate duration and intensity is strongly recommended to individuals with susceptibility to diabetes as a result of sex and family history, but without overweight/obesity.

ANALYSIS OF DYNAMICS IN THE DEVELOPMENT OF MOTOR SKILLS OF STUDENTS IN UNIVERSITY OF FORESTRY AFTER THE APPLIED MODEL FOR INCREASING PHYSICAL ABILITY

The optimization of physical activity of students is directly related to the issue of improving their physical abilities. Proper physical development and a high degree of physical activity are essential basis on which they should be built as socially active individuals. The objective of this study is to track and analyses the changes occurred in the physical abilities indicators of students from the University of Forestry after applying a model to develop motor skills. In this survey, 187 students have been involved and evaluated with a test battery, consisted of ten physical fitness tests, conducted at the beginning and at the end of the experiment. We used a variational and comparative analysis to process the survey results.

Physical inactivity during leisure time and irregular meals are associated with functional gastrointestinal complaints in middle-aged and elder subjects

Objectives: Few studies have examined how lifestyle factors affect functional gastrointestinal disorders. The aim of this study was to see if leisure time physical inactivity, dietary habits or body mass index (BMI) were associated with increased risk of functional abdominal pain, functional bloating, functional constipation or functional diarrhea.Methods and materials: This study was based on a questionnaire as part of the Swedish EpiHealth study. The cohort included 16,840 subjects between 45 and 75 years of age. Subjects with organic gastrointestinal diseases were excluded. Gastrointestinal symptoms were defined as functional abdominal pain, functional bloating, functional constipation and functional diarrhea. A meal (breakfast, lunch and dinner) was considered irregular if not taken every day. The impact of leisure time physical activity, dietary habits and BMI on functional symptoms were examined by logistic regression, adjusted for age, gender, socio-economy, smoking and alcohol habits.Results: Higher the degree of physical activity, lower the risk for all kind of gastrointestinal complaints (p ≤ 0.001). Intakes of lunch more seldom or never versus every day were associated with diarrhea (OR: 1.592; 95% CI: 1.046–2.422). Irregular breakfast habits tended to associate with bloating (OR: 1.366; 95% CI 0.995–1.874). BMI was not significantly associated with gastrointestinal complaints, but BMI ≥25 kg/m2 tended to reduce risk of constipation compared with BMI <25 kg/m2.Conclusion: Physical inactivity during leisure time shows independent associations with all functional gastrointestinal symptoms, whereas irregular dietary habits mainly associates with functional diarrhea. Higher degree of physical activity is associated with corresponding risk reductions of symptoms.

Clinical Relevance of Vertebral Fractures in Men.

Clinical Relevance of Vertebral Fractures in Men.

Body mass but not vitamin D status is associated with bone mineral content and density in young school children in northern Sweden

BackgroundHigh latitude of residence where sun exposure is limited affects vitamin D status. Although vitamin D levels have been associated with poor bone health, cut-off values for optimising bone health are yet to be decided.ObjectiveTo assess vitamin D intake and status among young school children living at latitude 63–64 °N, in northern Sweden and to examine the association between vitamin D status and bone mineral content (BMC) and bone mineral density (BMD).DesignIn a cross-sectional study, diet was assessed by a 4-day food diary and a food frequency questionnaire in 8- to 9-year-old children (n=120). Energy, vitamin D, and calcium intakes were calculated. Physical activity was assessed using a pedometer for 7 days. Serum 25-hydroxyvitamin D (S-25[OH]D) levels were analysed by high-pressure liquid chromatography-atmospheric pressure chemical ionisation-mass spectrometry (n=113). BMC and BMD were assessed by dual energy X-ray absorptiometry scan. Height and weight were measured by standard procedures and BMI z-score was calculated using WHO AnthroPlus programme.ResultsThe majority of children, 91%, did not reach the recommended vitamin D intake of 7.5 µg/day and 50% had insufficient S-25[OH]D levels defined as <50 nmol/l. The highest concentrations of S-25[OH]D were observed during the summer months (p=0.01). Body mass (p<0.01) but not S-25[OH]D was associated with measures of BMC and BMD. Furthermore, boys had higher total BMC (p=0.01), total body less head BMC (p=0.02), fat free mass (p<0.01), and a higher degree of physical activity (p=0.01) compared to girls.ConclusionsBody mass was related to BMC and BMD measures in a population of prepubertal school children living at high latitudes in Sweden. Despite insufficient S-25[OH]D levels and low vitamin D intake, this did not appear to affect bone parameters. Prospective studies with repeated assessment of vitamin D status are needed to examine cut-off values for optimising bone health.

The influence of regional deprivation index on personal happiness using multilevel analysis.

OBJECTIVES:The objective of the present study was to identify the factors that influence the happiness index of community residents, by considering personal and regional aspects, and to use as evidence of efforts for improvement of the happiness index.METHODS:The study was conducted based on information from 16,270 participants who met the data requirement among those who participated in the 2011 South Gyeongsang Community Health Survey. Of the factors that can influence the happiness index, socioeconomic characteristics, health behavior, morbidity, and healthcare use, social contact, and participation in social activities were classified as personal factors; for regional factors, data from the 2010 census were used to extrapolate the regional deprivation indices at the submunicipal-level (eup, myeon, and dong) in South Gyeongsang Province. The happiness index for each characteristic was compared to that for others via t-test and ANOVA, and multilevel analysis was performed, using four models: a basic model for identification of only random effects, model 1 for identification of personal factors, model 2 for identification of regional factors, and model 3 for simultaneous consideration of both personal and regional factors.RESULTS:The mean happiness index was 63.2 points (64.6 points in males and 62.0 points in females), while the mean deprivation index was -1.58 points. In the multilevel analysis, the regional-level variance ratio of the basic model was 10.8%, confirming interregional differences. At the personal level, higher happiness indices were seen in groups consisting of males with high educational level, high income, high degree of physical activity, sufficient sleep, active social contact, and participation in social activities; whereas lower happiness indices were seen in people who frequently skipped breakfast, had unmet healthcare needs, and had accompanying diseases, as well as those with higher deprivation index.CONCLUSIONS:The study confirmed that the happiness index of community residents was influenced by not only personal aspects but also various regional characteristics. To increase the happiness index, interests at both personal and regional levels, as well as community emphasis on creating social rapport and engaging in selective efforts, are needed in vulnerable regions with relatively high deprivation index.

Cancer incidence in participants in a long-distance ski race (Vasaloppet, Sweden) compared to the background population

BackgroundWe studied the association between taking part in a long distance ski race and cancer incidence to address the hypothesis that a lifestyle involving a high degree of physical activity (PA) lowers cancer incidence with a pattern that is different by cancer site. MethodsCancer incidence was estimated in a large cohort of skiers (n=185,412) participating in the Vasaloppet long distance ski race in Sweden 1989–2010 and non-participants in the ski race, randomly selected from the Swedish general population (n=184,617). Data include race finishing times as a measurement of physical fitness.Hazard ratios (HRs) and net probability of cancer over twenty years of follow-up were estimated for all invasive cancer, and separately for prostate, breast, colo-rectal and lung cancer, and groups of cancers with presumed relation to lifestyle. FindingsParticipating in Vasaloppet was associated with a relative risk reduction for all invasive cancer of 6% (95% confidence interval 2–9%) and a relative risk reduction of 32% (95% confidence interval 28–37%) of cancer sites where there is epidemiological evidence that smoking, bodyweight, regular PA and consumption of fruit and vegetables are aetiological factors. For skin cancer the risk was increased, as for prostate cancer. Skiers with shorter finishing times had lower incidence of cancer. InterpretationThis study indicates that it is unrealistic to reduce overall population cancer incidence drastically with life style. However, cancers that are epidemiologically associated with life style factors were significantly reduced by what presumably is a blend of non-smoking, normal body weight, sound dietary habits and PA. Our data thus provide additional support for present days’ recommendations about life style prevention. Higher health awareness is associated with attendance to screening, which may explain our results for prostate cancer. FundingUniversity fund, independent funds from an insurance company and a private foundation.

Identifying common metrics for evaluating school-based healthy lifestyles programs in seven countries: introduction to workshop proceedings.

The worldwide childhood obesity pandemic highlights the need to instill healthy lifestyle habits in children and youths, in particular fostering and facilitating healthy eating behaviors and a high degree of physical activity. To achieve this it's important to strengthen local program evaluation capacity. To summarize the proceedings of the seven-country School-Based Healthy Lifestyles Program Evaluation Workshop held in Granada, Spain, on 13-14 September 2013 under the auspices of the Mondelēz International Foundation. Synthesis of workshop proceedings including illustrative participants' quotes. All seven countries' programs were successful at developing and presenting their Program Impact Pathway (PIP) analysis at the workshop. All countries found their PIP analyses useful and improved them based on feedback received at the workshop. As illustrated by the participants' quotes the PIP analyses proved to be very useful in leading to in-depth critical thinking and discussion about ways to improve the programs' processes, oversight, and outcomes.

Mechanical stress and Wnt signal

Osteocytes sense mechanical stress and specifically express sclerostin. Sclerostin suppresses osteoblastic function by inhibiting Wnt/β-catenin pathway. The disruption of Sost gene encoding sclerostin causes resistance to the reduction of bone volume and bone formation after skeletal unloading. Transgenic mice with high expression of Sost gene show no increase in bone formation after skeletal loading. Sost gene is essential for alteration of bone formation after mechanical stress. In humans, high degree of physical activity is associated with low concentration of serum sclerostin, while immobilization is associated with high concentration of serum sclerostin. Concentration of serum sclerostin well correlates with bone turnover markers.

Ability to perform a single heel‐rise is significantly related to patient‐reported outcome afterAchilles tendon rupture

This study evaluated the short-term recovery of function after an acute Achilles tendon rupture, measured by a single-legged heel-rise test, with main emphasis on the relation to the patient-reported outcomes and fear of physical activity and movement (kinesiophobia). Eighty-one patients treated surgically or non-surgically with early active rehabilitation after Achilles tendon rupture were included in the study. Patient's ability to perform a single-legged heel-rise, physical activity level, patient-reported symptoms, general health, and kinesiophobia was evaluated 12 weeks after the injury. The heel-rise test showed that 40 out of 81 (49%) patients were unable to perform a single heel-rise 12 weeks after the injury. We found that patients who were able to perform a heel-rise were significantly younger, more often of male gender, reported a lesser degree of symptoms, and also had a higher degree of physical activity at 12 weeks. There was also a significant negative correlation between kinesiophobia and all the patient-reported outcomes and the physical activity level. The heel-rise ability appears to be an important early achievement and reflects the general level of healing, which influences patient-reported outcome and physical activity. Future treatment protocols focusing on regaining strength early after the injury therefore seem to be of great importance. Kinesiophobia needs to be addressed early during the rehabilitation process.

Adverse Events Associated with Testosterone Administration

To the Editor: In their study involving elderly men with impaired mobility, Basaria et al. (July 8 issue)1 found that men who received testosterone treatment, as compared with those who received placebo, had a higher rate of cardiovascular adverse events. Apart from the reasons discussed by the authors, this observation may also be a consequence of a higher degree of physical activity among the men receiving testosterone supplementation. In line with this hypothesis, limited physical vigor has been associated with total testosterone levels below 13 nmol per liter, a threshold crossed by the intervention.2 The beneficial effects of long-term physical activity notwithstanding, a body of evidence suggests that short-term physical exertion can precipitate myocardial infarction, sudden death, stroke, and acute left ventricular dysfunction.3,4 The authors found that the men in the intervention group had improved muscle performance and physical function after 6 months, but unfortunately the authors do not report about possible changes in the level of physical activity over the course of the study period. This information would be valuable, since the reported data do not preclude the possibility that the risk of adverse events associated with testosterone supplementation in elderly men can be reduced by the avoidance of sudden and inadequate physical exertion.