From the subarctic to the tropics: effects of 4-month deployment on soldiers' heat stress, heat strain, and physical performance.

The aim of the study was to evaluate the heat stress of Finnish male soldiers (N = 20, age 22.0 ± 2.5 years, body mass 78.8 ± 11.5 kg, and height 180.2 ± 5.6 cm) during their 4-month deployment in a hot environment and to find out the effects on physical performance and body composition. The troops moved from 2.5° C (mean monthly temperature) in Finland to 31.9° C in Chad. During the deployment, temperatures varied between 13.5 and 57.0° C outdoors and in the vehicles and tents. During 1-day recording in the middle of the deployment, skin temperatures were 34-35° C during daytime and maximal core temperature remained mainly below 38.0° C. Body mass decreased (78.4 ± 11.5 kg vs. 75.6 ± 8.6, p = 0.007) during the deployment without changes in fat mass. The sit-up performance increased by 10.9% (46 ± 10 reps·min⁻¹ vs. 51 ± 7 reps·min⁻¹, p < 0.01), and the maximal force production of the leg extensor muscles increased (3,042 ± 614 N vs. 3,277 ± 706 N, p < 0.05) without change in the rate of force development. No changes were observed in the push-ups, repeated squats, maximal grip strength, and running distance during the 12-minute test. In conclusion, the soldiers were able to maintain or improve their physical performance during the deployment despite the heat stress. It is important to encourage soldiers to engage in physical training, especially during a thermally appropriate time of the day or in air-conditioned facilities. Monitoring of local heat stress is also recommended.

Orthopaedic manual therapy, McKenzie method or advice only for low back pain in working adults: a randomized controlled trial with one year follow-up.

OBJECTIVE: To examine the effects of 2 manual therapy methods compared with one counselling session with a physiotherapist with "advice-only to stay active" for treating low back pain/leg pain and disability. DESIGN: A randomized, controlled trial with a 1-year follow-up. SUBJECTS: A total of 134 subjects with low back disorders. METHODS: Participants with acute to chronic first or recurrent low back pain, excluding those with "red flag" criteria, were assigned randomly to one of the 3 intervention groups: an orthopaedic manual therapy group (n=45), a McKenzie method group (n=52), and an "advice only to be active" group (advice-only) (n=37). Data on leg and low back pain intensity and disability (Roland-Morris Disability questionnaire) were collected at baseline, and at 3-, 6-, and 12-month follow-up points. RESULTS: At the 3-month follow-up point, significant improvements had occurred in all groups in leg and low back pain and in the disability index, but with no significant differences between the groups. At the 6-month follow-up, leg pain (-15 mm; 95% confidence interval (CI) -30 to -1), back pain (effect: -15 mm; -27 to -4), and disability index (-4 points; -7 to -1) improved (p < 0.05) more in the McKenzie method group than in the advice-only group. At the 1-year follow-up, the McKenzie method group had (p=0.028) a better disability index (-3 points; -6 to 0) than did the advice-only group. In the orthopaedic manual therapy group at the 6-month and 1-year follow-up visits, improvements in the pain and disability index were somewhat better than in the advice-only group (p=0.067 and 0.068, respectively). No differences emerged between the orthopaedic manual therapy and McKenzie method groups in pain- and disability-score changes at any follow-up. CONCLUSION: The orthopaedic manual therapy and McKenzie methods seemed to be only marginally more effective than was one session of assessment and advice-only.

Heritability of BMD of femoral neck and lumbar spine: a multivariate twin study of Finnish men.

UNLABELLED: Of the 80% variation in BMD among male twins that is caused by genetics, part was explained by genetic influences on lifting strength and lean body mass/height. Lifting strength was significant in both the femoral and spine BMD and body weight only for lumbar BMD. INTRODUCTION: The dominant role of heritability in BMD has been shown in twin studies among women. However, the mechanisms of genetic influences are poorly understood. BMD is associated with lean body mass and muscle strength, which both have a genetic component, but the relative effects of muscle strength and lean body mass/height on the total genetic and environmental variations influencing BMD of men are unclear. MATERIALS AND METHODS: Measurements of BMD from a DXA scanner on a representative sample of 147 monozygotic and 153 dizygotic male twin pairs (age, 35-70 yr) were related to a variety of anthropometric and behavioral covariates and interview data. Data were analyzed with univariate modeling of genetic characteristics, bivariate modeling of covariates that were significant in univariate models, and multivariate modeling of the simultaneous effects of significant covariates from the bivariate models. RESULTS: Heritability influences were estimated to account for 75% of the variance in femoral BMD and 83% in lumbar BMD. Univariate and bivariate modeling showed that, of the factors studied, only lifting force and lean body mass/height had statistically significant influences. Of the total genetic variation in femoral BMD, lifting force explained 9%, and lean body mass/height 18%; the proportions for lumbar BMD were 9% and 11%, respectively. Of the total environmental variation, the correlation with isokinetic lifting force explained 9% for femoral BMD and 10% for lumbar BMD. The genetic correlations between lifting force and femoral and lumbar BMD were approximately 0.3, as were the environmental correlations of isokinetic lifting force and femoral and lumbar BMD and of lean body mass/height and femoral BMD. The environmental correlation of lean body mass/height and femoral BMD was not significant. CONCLUSIONS: Lifting force had effects on both femoral and lumbar BMD. Body weight was important, but only for lumbar BMD. Muscle strength may have the best potential for modification among behavioral factors to increase both femoral and lumbar BMD.

Impairments, activity limitations and participation restrictions 6 and 12 months after breast cancer operation.

OBJECTIVE: To describe the impairments of upper body and limbs, activity limitations and participation restrictions 6 and 12 months after operation for breast cancer and to examine the impact of impairments on activity limitations. DESIGN: A prospective survey 6 and 12 months after operation. PATIENTS: Ninety-six breast cancer patients. METHODS: A questionnaire for assessing the impairments, activity limitations and participation restrictions was developed. RESULTS: The most common impairments 6 months after operation were breast and axilla scar tightness, axilla oedema and neck-shoulder pain. At 12-month follow-up the breast scar tightness (p=0.008) and axilla oedema (p=0.023) decreased, and limb ache (p=0.005) increased significantly. The most limiting impairments were axilla oedema and limb numbness 6 months after operation, and at 12-month follow-up axilla oedema. Lifting, carrying and reaching out caused worsening of impairments to more than half of the respondents at 6-month follow-up. Regression analysis showed that many impairments together were determinants of activity limitations and sleep impairment. Participation restrictions were constant. Respondents had not given up participation in activities in the home, but some had abandoned leisure activities and felt that their work ability had decreased. CONCLUSION: Impairments and their impact on activities were frequent and constant. There is an urgent need for developing rehabilitation protocols for breast cancer patients.

Multivariate genetic analysis of lifetime exercise and environmental factors.

PURPOSE: We investigated whether the association between exercise and individual-specific factors that correlate with exercise may be explained by genetic or common environmental factors. METHODS: Lifetime exercise data were available from 147 MZ and 153 DZ adult male twin pairs with a mean age of 50 yr (SD = 8 yr). RESULTS: The best-fitting quantitative genetic model for adulthood exercise level consisted of additive genetic effects, genetic effects due to dominance and unique environment effects, with genetic effects explaining 51% (95% CI = 29-63%) of the variance. Factors associated with adulthood exercise level were adolescent exercise, participation in competitive sports, perceived health, smoking status, and percent body fat. In bivariate models, approximately half of the covariation between those factors and adulthood exercise level was accounted for by unique environmental effects (i.e., factors not shared by the co-twins). Additive genetic effects explained less (3-20%) than dominance genetic effects (23-53%) of the covariation between those factors and adulthood exercise. Shared environmental effects were present only in the bivariate model of adulthood and adolescent exercise, explaining 11% of the covariance. CONCLUSIONS: : The genetic component shared in common by exercise and factors associated with exercise suggests that there may be a complex pathway of genetic selection and predisposition for a physically active lifestyle.

Relative roles of heredity and physical activity in adolescence and adulthood on blood pressure.

Part of the association between physical activity and low blood pressure (BP) may be a consequence of genetic selection. We investigated the association of genetic factors and physical activity in adolescence and adulthood with BP. BP was measured with a Finapres device in 71 monozygotic and 104 dizygotic male twin pairs using no antihypertensive medication. Subjects' mean age was 50.4 yr (range 40-72 yr). Subjects were interviewed about their lifetime exercise and other health habits. Exercise was classified as aerobic, power, or other, and these were further divided into adolescence (12-20 yr of age), the previous year, and lifetime. Genetic modeling was conducted to estimate genetic and environmental components of variance of systolic and diastolic BP. Aerobic exercise in adolescence and high-intensity aerobic exercise throughout the lifetime were associated with low diastolic BP in adulthood. Of the variance in diastolic BP, genetic factors accounted for 35% and aerobic exercise in adolescence for 5%. For systolic BP, genetic factors accounted for 39% of the variance. In turn, genetic factors accounted for 44% of the variance in aerobic exercise in adolescence. The genetic factors in part accounting for the variance in diastolic BP and those in part accounting for variance in aerobic exercise in adolescence were correlated. The association between aerobic exercise in adolescence and low diastolic BP in adulthood is a new finding, as is the observation that the factors partly share the same genes.

Postoperative education concerning the use of the upper limb, and exercise and treatment of the upper limb: cross-sectional survey of 105 breast cancer patients.

In this retrospective survey we investigated the recall of breast cancer patients (n=105) 6 months after the operation concerning postoperative instructions on exercises for shoulder mobility, and instructions for oedema prevention and treatment, upper limb strength training and the use of the upper limb in daily activities. Patients also described the content in their own words and ranked the instructors who had mostly given this education. Operation type and length of hospital stay did not have any effect on the education recalled, but the age of the respondent had some effect (r=-0.23, p<0.05). The Wilcoxon signed ranks test showed that the most commonly reported item was instructions on shoulder movements (P<0.001). Patients reported that they had more instructions for using the upper limb in daily activities than instructions for strength training (P=0.002) and oedema prevention and treatment (P=0.001). Patients own comments were sometimes conflicting: "Use the upper limb as before and you can even lift weights" and "You cannot drive a car or lift a weight over 3 kg for 6 weeks". Over half of the respondents named the physiotherapist or physiotherapy assistant as the person who had given them most of the instructions. A medical doctor was ranked in first place by 19% of the patients. Only half of the patients reported that they had some education after hospitalization. This study suggests that postoperative education of breast cancer patients is inconsistent and insufficient to provide knowledge for independent rehabilitation for future.

Genome-wide linkage scan for physical activity levels in the Quebec Family study.

PURPOSE AND METHODS: It is commonly recognized that there is familial aggregation for physical activity level. However, the genes and sequence variants responsible for the familial clustering have not been investigated. We performed a genome-wide linkage scan based on 432 markers typed in 767 subjects from 207 families of the Quebec Family study with the aim of identifying loci affecting physical activity levels. Four physical activity level phenotypes were used. RESULTS: Promising evidence of linkage (P < 0.0023) was found for physical inactivity on chromosome 2p22-p16. Suggestive linkages (0.0023

A dopamine D2 receptor gene polymorphism and physical activity in two family studies.

A role for dopamine neurotransmission in the regulation of motor activity and reinforcement of behavior is supported by considerable evidence. We studied the association between a marker in the dopamine D2 receptor gene (DRD2) and physical activity level in two cohorts. A first cohort consisted of 721 participants from 161 families of the Quebec Family Study (QFS). Physical activity phenotypes were obtained from a three-day diary and a questionnaire probing physical activity during the past year. The second cohort was the HERITAGE Family Study (HERITAGE), which included 275 Black and 497 White participants from 228 families, among whom past year leisure time and occupational physical activity were probed. A fragment length polymorphism in exon 6 of the DRD2 gene was detected by the polymerase chain reaction (PCR) and NcoI digestion. Frequencies for the T and C alleles were 28% and 72% in the QFS. In the QFS, TT homozygote women had 25% and 34% lower age and BMI-adjusted physical activity level during the past year, compared to CC homozygotes and CT heterozygotes (F=4.42, P=.016). The DRD2 genotype was not associated with the QFS phenotypes obtained from the three-day diary. In the HERITAGE, the frequency of the T allele was 30% among Whites and 63% among Blacks. Similarly, the TT homozygote White women had 29-38% lower sports index (F=4.09, P=.023) and 27-33% lower work index (F=6.23, P=.004) than the CC homozygotes and CT heterozygotes. The results suggest that DNA sequence variation in the DRD2 gene is associated with physical activity levels among White women.