Biomedical subjects

P Oja

Publications and source records attributed to P Oja.

At least 37 records · Page 2Linked to original sources

PubMed2000

Prediction of change in maximal aerobic power by the 2-km walk test after walking training in middle-aged adults.

The aim was to study the 2-km walk test's accuracy in predicting maximal aerobic power (VO2max) and its changes during 15-week walking training in 108 healthy middle-aged adults. Training prescription was 65-75% of VO2max 50 min/session, four times weekly. VO2max was measured walking on a treadmill and predicted from the 2-km walk test using gender-specific equations including age, body mass index, performance time and heart rate. The difference in VO2max between the walk test and the maximal exercise test before training was -0.9 ml x min(-1) x kg(-1) (SD 4.4) in men and -2.2 (3.5) in women. The total error was from 4.1 to 4.5 ml x min(-1) x kg(-1). After training the increase in measured VO2max was 2.9 ml x min(-1) x kg(-1) more in the walkers compared to the controls. The difference between the predicted and measured changes in VO2max during training ranged from -1.8 to -1.0 ml x min(-1) x kg(-1) between the study groups except in walking men, for whom the walk test overestimated the difference. The total error was from 3.1 to 4.9 ml x min(-1) x kg(-1). The 2-km walk test can be used as a reasonably accurate field test to predict changes in VO2max due to aerobic training in healthy nonathletic adults.

Adult↗

PubMed2000

Physical activity, fitness and body composition of Finnish police officers: a 15-year follow-up study.

This study evaluated changes in the physical activity, fitness and body composition of 103 police officers during a 15-year follow-up. The absolute aerobic capacity was similar in 1981 and 1996, muscular performance had declined, and body weight had increased approximately 0.5 kg/year. More than half the subjects (53%) had increased their leisure-time physical activity in 1996. The correlation was significant between physical activity in 1981 and physical fitness in 1996, but weak between physical activity in 1996 and fitness in 1996. It was also significant between waist circumference and waist/hip ratio in 1996 and physical activity during the previous 5 and 15 years. No significant correlations were found between physical activity and work ability or perceived physical or mental job stress. The physical fitness of middle-aged police officers seems to be predicted strongly by physical activity in early adulthood. Therefore health and fitness promotion measures should start at that time. This, together with regular systematic training, should help to sustain work ability of middle-aged police officers.

Adult↗

PubMed2000

Controlled 5-mo aerobic training improves heart rate but not heart rate variability or baroreflex sensitivity.

Endurance-trained athletes have increased heart rate variability (HRV), but it is not known whether exercise training improves the HRV and baroreflex sensitivity (BRS) in sedentary persons. We compared the effects of low- and high-intensity endurance training on resting heart rate, HRV, and BRS. The maximal oxygen uptake and endurance time increased significantly in the high-intensity group compared with the control group. Heart rate did not change significantly in the low-intensity group but decreased significantly in the high-intensity group (-6 beats/min, 95% confidence interval; -10 to -1 beats/min, exercise vs. control). No significant changes occurred in either the time or frequency domain measures of HRV or BRS in either of the exercise groups. Exercise training was not able to modify the cardiac vagal outflow in sedentary, middle-aged persons.

Adult↗

PubMed1999

Comparison of bicycle, heavy isometric, dipyridamole-atropine and dobutamine stress echocardiography for diagnosis of myocardial ischemia.

Several stress echocardiography (SE) modalities have been introduced for diagnosing coronary artery disease (CAD). Exercise and dobutamine SE are considered to have better diagnostic accuracy than vasodilator or isometric SE, but there are no studies in a single group of patients comparing these 3 tests with heavy 2-arm isometric SE. The purpose of this study was to determine the diagnostic characteristics of 4 SE methods in patients with chest pain. Altogether, 60 patients (age +/- SD 55.1 +/- 2.1 years) were tested with bicycle, heavy 2-arm isometric, dipyridamole-atropine and dobutamine SE. CAD (>50% stenosis) was present in 44 patients; 26 patients had 1-vessel disease. During bicycle SE, the double product at peak stress was higher than during dobutamine and dipyridamole-atropine SE (26.5 x 10(3), p <0.005 vs dobutamine and dipyridamole-atropine SE), and peak wall motion score index (1.40) was higher than during dipyridamole-atropine and isometric SE (1.26 and 1.07, respectively, p <0.05 vs bicycle SE). Bicycle, dipyridamole-atropine, and dobutamine SE had higher sensitivity than isometric SE (90%, 93%, 95%, and 30%, respectively, p <0.05 isometric SE vs others). There were no statistically significant differences with regard to specificity. Similarly, bicycle, dipyridamole-atropine, and dobutamine SE had a higher diagnostic accuracy than isometric SE (78%, 88%, 87% and 47%, respectively, p <0.05 isometric SE vs others). We conclude that bicycle, dipyridamole-atropine, and dobutamine SE have an equal diagnostic accuracy in detecting CAD despite higher double product and ischemic burden at peak stress during bicycle and dobutamine SE over dipyridamole-atropine SE. Heavy isometric SE is inaccurate.

Adult↗

PubMed1999

Relationship of angiotensin-converting enzyme gene polymorphism to carotid wall thickness in middle-aged men.

The insertion/deletion (I/D) polymorphism of the human angiotensin-converting enzyme (ACE) gene is a major determinant of circulating ACE levels. The D allele has been suggested to be a potent risk factor for coronary artery disease; however, the effect of the ACE gene on carotid atherosclerosis remains controversial. We therefore studied the relationship between the ACE gene I/D polymorphism and carotid artery intima-media thickness (IMT). A random sample of 300 men aged 50-59 years living in southern Finland were selected, and 233 agreed to participate (74%). Data were collected in 219 subjects. Quantitative B-mode ultrasonography was used to measure the maximum near and far wall IMT of right and left common, bifurcation, and internal carotid artery. The mean maximum IMT (overall mean) was calculated as the mean of 12 maximum IMTs at 12 standard sites. Patients with an IMT higher than 1.7 mm in at least one of 12 standard sites were assumed to have carotid atherosclerosis. The I/D polymorphism was determined by polymerase chain reaction. Overestimation of the frequency of the DD genotype was eliminated by insertion-specific primer and the inclusion of 5% dimethylsulfoxide. No significant differences were found in carotid wall thickness between the three genotypes; the overall mean IMT were 1.18 +/- 0.30, 1.22 +/- 0.24, and 1.08 +/- 0.40 mm in genotypes of II, ID, and DD, respectively. Similarly, the ACE genotypes and allele frequencies did not differ significantly between the subjects with and those without carotid atherosclerosis. There was no association in the subgroups among only nonsmoking subjects or subjects without chronic medication. The present data indicate that the I/D polymorphism of the ACE gene is not related to carotid IMT and is unlikely to play a major role in carotid atherosclerosis.

Carotid Arteries↗

PubMed1999

Disproportionate, age-related bone loss in long bone ends: a structural analysis based on dual-energy X-ray absorptiometry.

The width of long bone diaphyses apparently increase with age, a phenomenon that is suggested to have some positive impact on bone strength. On the other hand, these changes in size that are site-specific may cause a deterioration in the local mechanical integrity of the whole bone. Physical activity and calcium intake are known to be able to modify bone mass and size. It is, however, not known whether these lifestyle habits can modify the postulated disproportionate changes in bone size. To address this question, bone mineral content (BMC)-derived estimates of cross-sectional areas (CSA) of femur and radius in 158 premenopausal (mean age 43, standard deviation 2 years) and 134 postmenopausal (63 (2) years), clinically healthy women with contrasting long-term histories in physical activity and calcium intake were determined from dual-energy X-ray absorptiometry (DXA) data. The DXA-obtained BMC correlated strongly with the actual CSA (r = 0.94) determined with peripheral quantitative computed tomography. The ratios between functionally interrelated CSA data (i.e., (radial shaft CSA/distal radius CSA), (trochanter CSA/femoral neck CSA), (femoral shaft CSA/trochanter CSA) and (femoral shaft CSA/femoral neck CSA)) were considered primary outcome variables. Neither physical activity nor calcium intake separately or interactively were associated with any CSA ratio. Age showed no interaction with physical activity or calcium intake but was independently associated with all CSA ratios, except the ratio of femoral shaft CSA to trochanteric CSA. This study indicated clearly that a preferential reduction in the cross-sectional area occupied by bone mineral occurs disproportionately at the long bone ends as compared with diaphyseal sites, and this apparently inherent, age-associated relative loss seems not to be prevented by physical activity or calcium intake. In particular, given the utmost clinical relevance of the proximal femur region, an observed loss in femoral neck CSA of about 10% in contrast to about a 5% loss in trochanteric CSA warrants further investigation regarding its potential role as a predictor for hip fracture. Not only the local differences in bone composition but also the biomechanical aspects are important factors underlying these apparent changes in CSA at the studied skeletal sites.

Absorptiometry, Photon↗

PubMed1999

Eating control and physical activity as determinants of short-term weight maintenance after a very-low-calorie diet among obese women.

OBJECTIVE: To test the hypothesis that eating control and physical activity help maintain weight and waist circumference after a very-low-calorie diet. DESIGN: A 12 week weight reduction (WR) phase, followed by a 40 week weight maintenance (WM) phase. For the latter, the subjects were randomised into a no-exercise group and one of two groups with a walking program. SUBJECTS: Eighty-five obese (body mass index 29-46, mean 34), clinically healthy, premenopausal women. MEASUREMENTS: Body weight, waist circumference, body composition, the measuring restrained eating, disinhibition and hunger, measured by Three Factor Eating Questionnaire (TFEQ), binge eating measured by the Bulimic Investigatory Test of Edinburgh (BITE), and number of daily steps measured by a pedometer. RESULTS: The change (delta) in weight during WM was predicted by the following regression: deltaweight (kg)=5.23+0.45 deltaweight during WR+0.66 disinhibition during WM0.00039 daily steps during WM, r2=0.46, SEE 3.3 kg. The change in waist circumference during WM was predicted as deltawaist (cm)=0.76+0.75 deltaweight during WM0.00021 daily steps during WM, r2=0.67, SEE 2.6 cm. Exercise group assignment did not affect the changes in weight, waist circumference, or indicators of eating control during the maintenance program. CONCLUSIONS: Control of overeating, as indicated by a lower disinhibition factor of the TFEQ, and daily physical activity, as indicated by a higher number of daily steps, were positive and independent predictors of weight maintenance after a very-low-calorie diet. The number of daily steps showed an independent association with change in waist circumference during weight maintenance, even after adjustment for weight change.

Adult↗

PubMed1999

Factors affecting the relation between heart rate and energy expenditure during exercise.

This study evaluated the ability to use the relationship between heart rate (HR) and oxygen uptake (VO2) to estimate energy expenditure during physical activity (AEE). General prediction equations were established based on the individual relations between HR and AEE. Forty-two women, (mean age 38.1 [SD 9.8] years, BMI 23.9 [SD 4.4]), and 45 men (40.3 [SD 9.2] years, BMI 24.7 [SD 2.9]), carried out two incremental tests, one with a cycle ergometer and another on a treadmill. Subjects also performed a 10 minute steady-state exercise, cycling and walking. Respiratory gases were obtained from indirect calorimetry. AEE was calculated from VO2 and carbon dioxide production (VCO2). The predicted AEE was compared with the AEE measured during the steady-state exercise. Using the generalised linear model, two alternative models were found to predict AEE and HR. The first showed a three-way interaction between HR, body weight and gender (p = 0.022) and also between HR age and gender (p=0.083). The second produced a three-way interaction between HR, body weight and gender (p=0.057). For cycling and walking, respectively, the predicted AEE overestimated the actual AEE by 17.7 (SD 23.2)% and 6.2 (SD 19.3)% in the first model and by 17.9 (SD 22.7)% and 6.6 (SD 19.8)% in the second during the steady-state exercise. It was concluded that at least gender and body weight should be included when HR is used to predict AEE.

Adult↗

PubMed1999

Health-related fitness test battery for middle-aged adults: associations with physical activity patterns.

To evaluate the validity of a health-related fitness (HRFI) test battery with respect to physical activity (PA), we studied how PA patterns of adults are related to different components of HRFI with special interest in musculoskeletal and motor fitness. Subjects (n = 498) were middle-aged (37-57 years) men and women, evenly selected from five age cohorts of a representative population sample. PA was assessed with a questionnaire and classified into three PA groups. Fitness assessment included 9 simple field tests. The odds ratio of low fitness (least fit 40 %) of the measured dimension of HRFI for three PA groups with reference to inactive group were analysed. All PA groups were strongly related to Walk Test results in both genders, and to BMI in women. Muscular type exercise was associated with modified push-ups strength and static back extension endurance in both genders, and with one-leg standing balance in women. One-leg squat for leg strength, jump-and-reach for leg power, trunk side-bending flexibility and hamstring muscle extensibility tests were not associated with PA. Five of the nine fitness tests demonstrated plausible associations with PA patterns among adults suggesting activity-related validity. An exercise intervention study is needed to evaluate the sensitivity of the tests to fitness changes.

Adult↗

PubMed1999

Changes in bone mineral content with decreased training in competitive young adult tennis players and controls: a prospective 4-yr follow-up.

PURPOSE: The purpose of this 4-yr prospective follow-up study of male tennis players was to determine the changes in the playing-to-nonplaying arm differences in bone mineral content (BMC) and answer two questions: 1) Are training induced bone gains lost with decreased training? and 2) Are the possible bone changes related to the changes in training? METHODS: Subjects were 13 former competitive male tennis players and their 13 controls. The players had started their playing career at the mean age of 11 yr. The initial comparisons between the playing and contralateral arms' BMC were done in 1992 (mean age 26 yr), and follow-up was performed 4 yr later. The players were competing at the national top level in the beginning of the study, and all had retired from the top tennis (mean) 2.3+/-0.6 yr before follow-up. Accordingly, they had reduced the average training frequency from 5.2 times a week to 2.6 times a week and the mean hours of training per week from 7.6 to 3.3. RESULTS: The 1996 measurements revealed that on average the players' exercise-induced bone gain in the playing arm had not disappeared with time despite decreased average playing activity and that observed bone changes were not related to changes in training. The side-to-side BMC differences were largest in the humeral shaft (25% in 1992 and 26% 4 yr later) and the proximal humerus (19% and 18%). The radial shaft difference was 14% and the distal radius difference 13% in both 1992 and 1996. In controls, the side-to-side BMC differences were small, less than 5%, and they did not change by time. CONCLUSIONS: In conclusion, this study suggests that bone gain obtained by regular tennis training does not disappear by time despite decreased playing activity. Regular exercise can be valuable for maximizing peak bone mass and thus contributing to prevention of osteoporosis and related fractures later in life.

Adult↗

PubMed1999

Good maintenance of high-impact activity-induced bone gain by voluntary, unsupervised exercises: An 8-month follow-up of a randomized controlled trial.

The purpose of this study was to evaluate whether premenopausal women's voluntary unsupervised aerobic and step training could maintain the skeletal benefits obtained by an 18-month supervised high-impact training, and if so, to what extent. Thirty women of the original 39 study subjects (i. e., persons who completed the preceding 18-month randomized training intervention and who volunteered to continue the training on their own for a further 8 months) and 19 women of the 45 original control subjects (i.e., persons who volunteered to continue as controls) were included. The study group trained an average of twice per week and the training consisted of regular aerobic and step classes provided by local fitness centers. Areal bone mineral density (BMD, g/cm2) was measured from the lumbar spine, femoral neck, trochanter area of the femur, distal femur, patella, proximal tibia, calcaneus, and dominant distal radius at baseline and after 18 and 26 months. During the extended 8-month follow-up, the BMD of the study group increased more at the femoral neck (the intergroup change was +0.9% at 18 months and +2.8% at 26 months, p = 0.004 for the change between 18 and 26 months) and remained at the 18-month level at the distal femur, patella, proximal tibia, and calcaneus. In these sites, the statistically significant changes during the entire 26 months of training were 1.7-4.0% in the training group as compared with the changes of -0.9-1.5% in the control group. In the lumbar spine, BMD decreased from the 18-month level in both groups. In conclusion, the significant BMD increases that were obtained by supervised 18-month high-impact training were effectively maintained with subsequent unsupervised regular aerobic and step classes (twice per week). The finding emphasizes the effectiveness and feasibility of self-controlled aerobic and step exercises in the primary prevention of osteoporosis among healthy premenopausal women.

Adult↗

PubMed1999

Long-term recreational gymnastics, estrogen use, and selected risk factors for osteoporotic fractures.

The purpose of this cross-sectional study was to examine whether long-term participation in recreational gymnastics or folk dancing or estrogen replacement therapy (ERT) is associated with mechanically more competent bones and improved muscular strength and body balance. One hundred and seventeen healthy, female postmenopausal recreational gymnasts (mean age 62.1 [SD 4.7] years) and 116 sedentary controls (mean age 61.5 [4.6] years) were enrolled in the study. Bone mineral content (BMC) of the distal radius, femoral neck, and trochanter were measured with dual-energy X-ray absorptiometry. BMC of the midshaft and distal tibia and trabecular density (TrD) of the distal tibia were measured with peripheral computed quantitative tomography. Maximal isometric strength, muscular power, cardiorespiratory fitness, and body balance of the participants were also assessed. The cardiorespiratory fitness, muscular strength, and dynamic balance of the recreational gymnasts and folk dancers combined were significantly better than those of the controls, the average group difference ranging from 7.5% (95% confidence interval 5.0-9.9%) in dynamic balance to 12.8% (6.6-19. 4%) in dynamic muscular power. ERT was not associated with the fitness indicators, muscular power, or balance, but was significantly associated with the BMC at all the measured bone sites, the mean group difference between estrogen users and nonusers ranging from 6.5% (3.7-9.3%) for the tibial shaft to 11.8% (6.4-17. 0%) for the distal radius. Recreational gymnastics, in turn, was significantly associated with higher BMC at the tibia only, the mean group difference being 3.9% (0.9-6.9%) for the tibial shaft and 7.7% (3.7-11.9%) for the distal tibia. Recreational gymnastics was also associated with higher TrD at the distal tibia (5.2%; 1.2-9.2%), whereas estrogen usage did not show such association. The results indicate that ERT seems especially effective in preventing postmenopausal bone loss, whereas recreational gymnastics and folk dancing improve muscular performance and body balance in addition to increased bone mass and bone size in the tibia. All these factors are essential in prevention of fall-related fractures of the elderly.

Absorptiometry, Photon↗

PubMed1999

The impact of smoking, alcohol consumption, and physical activity on use of hospital services.

OBJECTIVES: This study investigated the associations of smoking, excess alcohol consumption, and physical inactivity with the use of hospital care. METHODS: A cohort of 19- to 63-year-old Finnish men (n = 2534) and women (n = 2668) were followed prospectively for 16 years. Number of hospital days was extracted from the national hospital discharge registry, while data concerning exposure variables were derived from the baseline questionnaire. RESULTS: After adjustment for confounders, male smokers had 70% (95% confidence interval [CI] = 49%, 95%) and female smokers had 49% (95% CI = 29%, 71%) more hospital days due to my cause than did those who had never smoked. Men consuming a moderate amount of alcohol had 21% (95% CI = 10%, 31%) fewer hospital days due to any cause than did nondrinkers. Men who had the lowest energy expenditure during leisure-time physical activity had 36% (95% CI = 15%, 63%) more hospital days than the most active men. The figure for women was 23% (95% CI = 4%, 44%). CONCLUSIONS: Smoking was strongly associated with an increased use of hospital services. The associations of alcohol consumption and leisure-time physical activity with use of hospital care depended on the diagnosis under study.

Adult↗

PubMed1998

Health-related fitness test battery for adults: associations with perceived health, mobility, and back function and symptoms.

OBJECTIVE: To evaluate the health-related content validity of nine fitness tests by studying how low, mid, and high levels of fitness are associated with perceived health and musculoskeletal functioning. DESIGN: Cross-sectional methodological study. SETTING: A research institute for health promotion. PARTICIPANTS: Middle-aged (37 to 57 years) men (n = 245) and women (n = 253), evenly selected from five age cohorts of a random population sample. MAIN OUTCOME MEASURES: The odds ratios (ORs) of selected health outcomes for low (least fit 20%), mid (next 40%), and high (most fit 40%) fitness categories in the different tests adjusted for several possible confounders. RESULTS: Cardiorespiratory fitness, as measured by 2-km walk test, was strongly and consistently associated with perceived health and mobility (stair climbing) in both genders (range of ORs, 2.4 to 17.6), and a somewhat weaker relationship was found with leg power and with leg strength (ORs, 2.5 to 7.2). Low fitness in back muscular endurance and upper-body strength were associated with mobility disability (ORs, 2.8 to 8.5) and with back dysfunction and pain (ORs, 2.9 to 6.1). High fitness in back endurance in men and in balance in women were related to positive back health (ORs, 2.5 to 3.7). Body mass index was associated with musculoskeletal disability in women (ORs, 2.4 to 5.3). Balance, leg strength, and leg flexibility in men; and leg power, trunk and leg flexibility in women were not associated with health outcomes. CONCLUSIONS: Among a middle-aged population, the majority of the evaluated fitness tests demonstrated health-related validity by strong associations with perceived health and musculoskeletal functioning, and by weaker associations with back symptoms.

Adult↗

PubMed1998

How to understand a community--community assessment for the promotion of health-related physical activity.

A definition of the concept of community is given and the principles and the major components of community assessment for health-related physical activity are presented. Definitions of community can include a focus on geographic, social or cultural elements. Basically community assessment deals with a process having two main aspects. The first, quantitative and descriptive aspect consists of a community profile, a wellness profile, a behavioural profile and a service profile. The second, qualitative and analytical aspect deals with organizational capabilities and the community's readiness for change. This information can be used for programme planning, implementation, and evaluation in the process of community development.

Adolescent↗

PubMed1998

Daily walking and cycling to work: their utility as health-enhancing physical activity.

The substantial health-enhancing potential of physical activity can be realised on population level best if people can incorporate physical activity into their daily life routines. Physically active commuting to and from work provides a promising mode for such activity. In a series of three studies we explored more specifically the population prevalence, the physiological effectiveness, and the promotional possibilities of commuting to work by walking and cycling in a mid-size Finnish town. The results of the questionnaire survey indicated that while about one-third of the working-age sample commuted by walking or cycling an additional one-quarter were in a position to either begin or increase physically active commuting. The controlled intervention study showed that this kind of moderate-intensity, high-frequency activity improved the health-related fitness and selected indices of metabolic health. The promotion project in a large industrial plant demonstrated that walking and cycling during work trips can be successfully promoted by relatively low cost measures. These experiences suggest that physically active commuting to work offers substantial potential as a health-enhancing measure for working-age population.

Adult↗

PubMed1998

How to develop local physical activity promotion programmes with national support: the Finnish experience.

Stimulated by recent research findings regarding the health effects of physical activity, an extensive policy development for sports and for health took place in Finland in the early 1990s resulting in two national programmes. The 'Finland on the Move' programme's aim was to stimulate new local projects by financial support, training and consultation services, and media promotion. The evaluation of the programme listed several general characteristics of successful local projects. The ongoing 'Fit for Life' programme is based on the experience gained from the previous programme, but is focused mostly on the 40-60-year-olds as a target group, and utilises a more intensive mass media approach. It is concluded that the two programmes have been successful in creating plenty of new local initiatives and increasing population participation related to physical activity. The Finnish experience demonstrates that deliberate efforts to communicate scientific knowledge can lead to a better acceptance of physical activity on the national level and that well-planned and sensitive state-level support of grassroots activities can succeed.

Adult↗

PubMed1998

Safety and feasibility of a health-related fitness test battery for adults.

BACKGROUND AND PURPOSE: Health-related fitness (HRFI) assessment may be useful in promoting physical activity. Health-related fitness refers to those components of fitness that are related to health status. The safety and feasibility of a test battery designed for the assessment of HRFI were evaluated. SUBJECTS AND METHODS: Middle-aged men (n = 246) and women (n = 254), evenly selected from five age cohorts of a random sample (N = 826), were tested. The subjects had a mean age of 47.0 years (SD = 7.9, range = 37-57). Screening to identify subjects with health limitations was conducted by fitness testers who had master's degrees in sport or health sciences. Safety was assessed in terms of acute complications, delayed-onset muscle soreness (DOMS), and heart rate after each test. Subject exclusion and time costs were evaluated for feasibility. RESULTS: No acute complications occurred. The leg function test caused severe DOMS among inactive women. The overall exclusion rate increased with age. Up to 27% of subjects aged 52 and 57 years were excluded from muscle endurance tests, mainly due to self-reported heart disease or elevated blood pressures. Over 90% of the subjects, however, qualified for balance, flexibility, muscle force, and walk tests. CONCLUSION AND DISCUSSION: The test battery offers a safe and feasible method for the assessment of HRFI in working-aged adults, with the limitation that the one-leg squat function test may cause DOMS, particularly in inactive women.

Adult↗