Dose-response relation of self-reported and accelerometer-measured physical activity to perceived health in middle age-the Northern Finland Birth Cohort 1966 Study

Background

Regular physical activity (PA) promotes health and decreases mortality. The positive relationship between PA and perceived health (PH) is well known. However, previous research in the field has often used self-reported PA measures. The aim of this population-based NFBC1966 birth cohort study was to assess the relationship between both self-reported and objectively measured PA and PH in midlife.

Methods

A sample group of 6384 participants (2878 men, 3506 women, response rate 62%) aged 46 completed a questionnaire on PH and health behaviors, including items on weekly leisure time physical activity (LTPA) and daily sitting time (ST). PH was dichotomized as good (very good or good) and other (fair, poor, or very poor). PA was measured with a wrist-worn Polar Active (Polar Electro, Finland) accelerometer for 14 days (n = 5481, 98%) and expressed as daily average time spent in moderate to vigorous intensity PA (MVPA). Odds ratios (OR) and 95% confidence intervals for good PH were calculated using binary logistic regression and adjusted for relevant demographic, socioeconomic, and health characteristics, and ST.

Results

The level of PA was positively associated with PH after adjustments with covariates and ST. There was a dose-response relationship across the PA quartiles according to the adjusted multivariable models. Self-reported LTPA was more strongly associated with good PH (OR from 1.72 to 4.33 compared to lowest PA quartile) than objectively measured PA (OR from 1.37 to 1.66 compared to lowest PA quartile).

Conclusions

In this large population-based birth cohort study, we for the first time show a positive dose-response relationship of both self-reported and objectively measured PA to PH, the relationship being stronger for self-reported LTPA. Despite the cross-sectional design of this study, the results from this large sample suggest that both self-reported and objectively measured physical activity are strongly associated with PH, which is a predictor of morbidity and mortality, and regular PA should be encouraged in midlife.

Effective Weight Loss and Maintenance by Intensive Start with Diet and Exercise

INTRODUCTION

This 24-month study aimed to determine whether exercise intervention added to weight loss treatment at 6 months is effective for weight loss and maintenance.

METHODS

A total of 120 obese subjects (body mass index > 30) were randomly assigned to intensified behavioral modification (iBM) (n = 30), behavioral modification + exercise from 0 to 3 months (circuit weight training group 1 [CWT1]) (n = 30), behavioral modification + exercise from 6 to 9 months (CWT2) (n = 30), and a control group (CON) (n = 30). Health behavior, weight, waist circumference, and 2-h glucose tolerance test with insulin measurements were measured at 0, 3, 9, and 24 months.

RESULTS

Eighty-five subjects (mean age = 46 yr, body mass index = 36.3, 75.3% women) completed the trial. A significant weight loss occurred in CWT1 (-8.5 kg, P > 0.001), iBM (-5.5 kg, P > 0.001), and CWT2 (-4.4 kg, P = 0.007). CWT1 showed the highest reduction in waist circumference at 9 months (mean difference = -11.5 cm, P < 0.001) and 24 months (mean difference = -8.8 cm, P < 0.001). Both fasting and 2-h insulin values improved in the intervention groups compared with CON. A significant decrease in 2-h insulin values from baseline was found in CWT1 and CWT2. Matsuda index improved in the CWT1 group from the baseline to 24 months (2.03, P = 0.025).

CONCLUSION

The most effective weight loss regimen is a combination of iBM and weight training introduced from the very beginning of the weight loss period. Treatment of morbid obesity should include an intensive start with exercise and diet regardless of weight status.

Muscular fitness in relation to physical activity and television viewing among young adults

PURPOSE

To study how time spent in physical activity and that in television (TV) viewing are associated with muscular fitness among young adults.

METHODS

The study population consisted of a cross-sectional sample of 381 males and 493 females aged 19.1 yr (SD 0.3) from the Northern Finland Birth Cohort 1986. Muscular fitness was measured by trunk muscle strength tests (trunk extension, flexion, and rotation) and jumping height test. Time spent on moderate- to vigorous-intensity physical activity and on TV viewing was self-reported by a questionnaire.

RESULTS

The most physically active young adults performed significantly better in most trunk muscle strength tests and the jumping test than the least active subjects. The mean difference between the most and least active groups was at minimum 1.6 kg (95% confidence interval (CI) = -0.5 to 3.7) and at maximum 10.6 kg (95% CI = 4.7-16.5) for different trunk muscle strength tests and at minimum 4.4 cm (95% CI = 2.7-6.1) for the jumping height test. Males and females who watched TV for >or=2 h x d(-1) performed significantly worse in trunk extension and flexion tests and females also performed worse in the jumping test compared with those who watched TV <2 h x d(-1), independent of their physical activity level. The mean difference between low and high TV users was at minimum -3.8 kg (95% CI = -6.7 to -0.9) for trunk extension and flexion strength and -1.2 cm (95% CI = -2.0 to -0.4) for jumping height in females.

CONCLUSIONS

Among young adults, daily TV viewing for >or=2 h, irrespective of physical activity level, was associated with poorer muscular fitness.