Physical activity from adolescence to adulthood and health-related fitness at age 31

Cross-sectional and longitudinal analyses of the Northern Finland birth cohort of 1966

Tuija Tammelin

Oulu Regional Institute of Occupational Health
Department of Public Health Science and General Practice, University of Oulu

Abstract

Regular physical activity, a high level of cardiorespiratory fitness and the maintenance of normal weight are strongly associated with several positive health outcomes across the lifespan. The aim of this study was to evaluate how physical activity and social status in adolescence are associated with physical activity in adulthood, and how a change in the level of physical activity from adolescence to adulthood is associated with overall and abdominal obesity in adulthood. This study also evaluated the relationship between occupational physical activity and physical fitness and produced reference values of cardiorespiratory fitness for males and females aged 31 years.

The study population consisted of the Northern Finland birth cohort of 1966 (N = 12,058). Data on physical activity and social situation at 14 and 31 years were collected by postal inquiries in 1980 and in 1997–1998, respectively. Cardiorespiratory fitness, muscular fitness and obesity were measured at medical examination at age 31.

Participation in sports twice a week or more after school hours, being a member in a sports club and a high grade in school sports at age 14 were associated with a high level of physical activity at age 31. Adolescent participation in rather intensive endurance sports, and some sports that require or encourage diversified sports skills appeared to be the most beneficial with respect to the enhancement of adult physical activity. Low social class and poor school achievements were associated with physical inactivity at age 14. Poor school achievements at age 14 were also associated with physical inactivity at age 31. Becoming inactive during the transition from adolescence to adulthood was associated with overall obesity in both genders and abdominal obesity in females at 31 years.

A linear dose-response relationship was observed between the frequency of participation in brisk exercise and cardiorespiratory fitness. The mean peak oxygen uptake was 43 ml·kg-1·min-1 in males and 34 ml·kg-1·min-1 in females. Very low levels of cardiorespiratory fitness were associated with a combination of infrequent participation in brisk exercise and increased body mass index. High level of occupational physical activity was associated with a high level of physical fitness, but low level of leisure-time physical activity at age 31.

The enhancement of regular participation in physical activity across the lifespan is an important challenge for public health promotion. The present results that define the predictors and correlates of physical activity can be used to identify the target groups for interventions to enhance continuous participation in physical activities. New information on physical fitness of young adults is useful in physical activity counseling when fitness test results are interpreted and the need for health-enhancing or fitness-improving physical activity is evaluated.

Tiivistelmä

Säännöllinen liikunta, hyvä fyysinen kunto ja normaali paino ovat yhteydessä hyvään terveyteen. Tämän tutkimuksen tavoitteena oli selvittää, miten liikunta-aktiivisuus ja sosiaaliset tekijät nuoruusiässä ovat yhteydessä liikunta-aktiivisuuteen aikuisena, sekä miten liikunta-aktiivisuuden muutos nuoruudesta aikuisikään on yhteydessä lihavuuteen ja keskivartalolihavuuteen aikuisena. Lisäksi selvitettiin raskaan ruumiillisen työn yhteyttä fyysiseen kuntoon nuorilla työntekijöillä ja luotiin aerobisen kunnon väestöpohjaiset viitearvot 31-vuotiaille.

Tutkimusaineiston muodosti Pohjois-Suomen syntymäkohortti 1966 (N = 12058). Liikunta-aktiivisuus selvitettiin postikyselyin 14- ja 31-vuotiaana vuosina 1980 ja 1997–1998. Aerobinen kunto, lihaskunto, lihavuus ja keskivartalolihavuus mitattiin 31-vuotiaana terveystarkastuksessa.

Urheilun harrastaminen kaksi kertaa viikossa tai useammin kouluajan ulkopuolella, kuuluminen urheiluseuraan ja hyvä liikuntanumero 14-vuotiaana olivat yhteydessä aktiiviseen liikkumiseen 31-vuotiaana. Intensiivisten kestävyyslajien sekä tiettyjen monipuolisia taitoja vaativien tai kehittävien lajien harrastaminen nuorena oli voimakkaimmin yhteydessä aktiiviseen liikkumiseen aikuisena. Heikko sosioekonominen asema ja heikko koulumenestys olivat yhteydessä liikkumattomuuteen 14-vuotiaana. Heikko koulumenestys 14-vuotiaana ennusti liikkumattomuutta myös 31-vuotiaana. Muutos liikunnallisesti aktiivisesta inaktiiviseksi 14 ja 31 ikävuoden välillä oli sekä miehillä että naisilla yhteydessä lihavuuteen ja naisilla keskivartalolihavuuteen 31-vuotiaana.

Maksimaalinen hapenottokyky oli kohortin 31-vuotiailla miehillä keskimäärin 43 ml·kg-1·min-1 ja naisilla 34 ml·kg-1·min-1. Ripeän liikunnan harrastaminen oli positiivisesti ja lineaarisesti yhteydessä maksimaaliseen hapenottokykyyn. Erittäin matala maksimaalinen hapenottokyky havaittiin niillä 31-vuotiailla, jotka harrastivat harvoin ripeää liikuntaa ja olivat ylipainoisia tai lihavia. Raskas ruumiillinen työ oli yhteydessä hyvään fyysiseen kuntoon mutta vähäiseen vapaa-ajan liikuntaan 31-vuotiailla työntekijöillä.

Liikunta-aktiivisuuden tukeminen elämänkulun eri vaiheissa on tärkeä haaste terveyden edistämisessä. Tämän tutkimuksen tuloksia liikkumattomuuteen liittyvistä nuoruusiän ja aikuisiän tekijöistä voidaan hyödyntää, kun määritellään kohderyhmiä interventioihin elinikäisen liikunnan edistämiseksi. Tuloksia nuorten aikuisten fyysiseen kuntoon liittyvistä tekijöistä voidaan hyödyntää käytännön liikuntaneuvonnassa, kun tulkitaan kuntotestien tuloksia ja määritellään tarvetta terveyttä edistävän ja fyysistä kuntoa kohottavan liikunnan lisäämiseksi.


Table of Contents
Acknowledgements
Abbreviations
List of original articles
1. Introduction
2. Review of the literature
2.1. Definitions of physical activity, fitness and health
2.2. Relationships between physical activity, fitness and health
2.2.1. Leisure-time and occupational physical activity in relation to fitness
2.2.2. Physical inactivity, low level of cardiorespiratory fitness and obesity as risk factors
2.3. Physical activity and health-related fitness – pathways from adolescence into adulthood
2.3.1. Pathway 1: Youth physical activity and adult physical activity
2.3.2. Pathway 2: Youth physical activity and youth health-related fitness
2.3.3. Pathway 3: Youth health-related fitness and adult health-related fitness
2.3.4. Pathway 4: Youth health-related fitness and adult physical activity
2.3.5. Pathway 5: Youth physical activity and adult health-related fitness
2.3.6. Pathway 6: Adult physical activity and adult health-related fitness
2.4. Measurement of physical activity and health-related fitness in epidemiological studies
2.5. Summary of the literature and justification for this study
2.5.1. Adolescent participation in different sports and adult physical activity
2.5.2. Adolescent predictors of physical inactivity in adulthood
2.5.3. Physical activity and obesity from youth to adulthood
2.5.4. Occupational physical activity and physical fitness in young adults
2.5.5. Population-based reference values of cardiorespiratory fitness for young adults
3. Aims of the study
4. Material and methods
4.1. Study population and data collection
4.1.1. Evaluation of the losses to follow–ups and representativeness of the study samples
4.1.2. Study variables
4.1.3. Physical activity
4.1.4. Health-related fitness
4.1.5. Other variables
4.2. Statistical methods
5. Results
5.1. Leisure-time physical activity and the background variables at ages 14 and 31
5.2. Participation in adolescent sports and adult leisure-time physical activity (I)
5.2.1. Association between adolescent sports and adult physical activity level
5.2.2. Different adolescent sports and the types of physical activity in adulthood
5.2.3. Social determinants of participation in adolescent sports
5.3. Physical activity and social status in adolescence as predictors of physical inactivity in adulthood (II)
5.4. Physical activity from adolescence into adulthood and obesity in adulthood (III)
5.5. Association between occupational physical activity and fitness in young adults (IV)
5.6. Cardiorespiratory fitness of young adults (V)
6. Discussion
6.1. Participation in adolescent sports and adult physical activity (I)
6.2. Physical activity and social status in adolescence as predictors of physical inactivity in adulthood (II)
6.2.1. Physical activity in adolescence and physical inactivity in adulthood
6.2.2. Social status in adolescence and physical inactivity in adulthood
6.2.3. Associations between social status and physical inactivity in adulthood
6.3. Physical activity from adolescence into adulthood and obesity in adulthood (III)
6.4. Association between occupational physical activity and fitness in young adults (IV)
6.5. Cardiorespiratory fitness of young adults (V)
6.5.1. Measurement of cardiorespiratory fitness
6.5.2. Reference values of cardiorespiratory fitness
6.5.3. Participation in brisk exercise and cardiorespiratory fitness
6.6. Methodological considerations
7. Summary of the findings and conclusions
References
A. 1
B. 2
C. 3
D. 4
E. 5
List of Tables
1. Study samples in articles I–V.
2. The explanatory, confounding and outcome variables used in the original articles (I–V)
3. Characteristics of males (N = 3,664) and females (N=4,130) at age 14 and 31 years.
4. a. Multinomial regression of physical activity levela at 31 years on types of sports at age 14 years in males. Odds ratiosb (OR) and their 95% confidence intervals (CI).
4. b. Multinomial regression of physical activity levela at 31 years on types of sports at age 14 years in females. Odds ratiosb (OR) and their 95% confidence intervals (CI).
5. Participation in different types of leisure-time physical activity at 31 years according to participation in certain types of sports at 14 years.
6. Background characteristics of males and females participating in different sports at age 14.
7. Percentages of physically inactivea individuals at age 31 by background characteristics, and multivariate logistic regression analysis of physical inactivitya at age 31. Odds ratios (OR) and their 95% confidence intervals (CI).
8. TPercentages of physically inactive subjects at 14a and 31byears by social class and school achievement at 14 years, and logistic regression analysis of physical inactivitya at 31 years. Unadjusted and adjusted odds ratios (OR) and their 95 % confidence intervals (CI).
9. Logistic regression of overall and abdominal obesity at 31 years on the change in the level of physical activity between the ages of 14 and 31. Odds ratios (OR) and 95 % confidence intervals (CI).
10. Regression models used to predict peak oxygen uptake (ml·kg·min–1) for the males and females
11. Model-predicted reference values of peak oxygen uptakea (ml·kg–1·min–1) based on 4,073 males and 4,368 females who participated in the health survey of the Northern Finland birth cohort of 1966 at age 31.
A-1. Summary of the longitudinal studies on physical activity in youth and from youth to adulthood. Age at baseline less than 25 years, follow-up time at least 2 years. PA = physical activity, LTPA = leisure-time physical activity, ↓ = decrease, ↑ = increase, y = years.
B-1. Summary of longitudinal studies on the association between physical activity and obesity from youth to adulthood. Follow-up time at least 2 years. BMI = body mass index, WC = waist circumference, WHR = waist to hip ratio, BF = body fat, SSF = sum of skinfolds, PA = physical activity, CVD = cardiovascular disease, y = years, ↓ = decrease, ↑ = increase
C-1. Summary of studies on the association between occupational physical activity and physical fitness. PA = physical activity, OPA = occuaptional physical activity, LTPA = leisure-time physical activity, M = males, F = females, ↓ = decrease, ↑ = increase, y = years.
E-1. Distibution (%) of certain variables at 14 years in different study samples.
E-2. Distibution (%) of certain variables at 31 years in different study samples.
E-3. Table 3. Mean value standard deviation of certain variables measured at 31 years in different study samples.
List of Figures
1. A model describing the relationships between physical activity, health-related fitness and health (Bouchard & Shephard 1994).
2. A model describing the relationships between physical activity and health-related fitness in youth and adulthood and potential pathways from youth to adulthood (modified after Blair et al. 1989, Malina 2001a and Twisk et al. 2002a).
3. The associations between physical activity and health-related fitness evaluated in the present study. Original articles are presented as I–V.
4. Study population and data collection of the Northern Finland birth cohort of 1966 from 1966 to 1997–1998.
5. Percentage of males and females who participated in a certain sport at age 14.
6. Percentage of males and females who participated in different types of physical activity once a week or more often at age 31.
7. Odds ratios (OR) and 95% onfidence intervals for being physically active (a) or very active (b) vs. inactive at leisure time at 31 years, according to the frequency of participation in sports after school hours at 14 years. Results are from multinomial logistic regression. l = males and ○ = females.
8. Results of the step test, handgrip test and trunk extension test according to following levels of occupational physical activity: 1) light sedentary work, 2) other sedentary work, 3) light standing or moving work, 4) medium heavy moving work, 5) heavy manual work and 6) very heavy manual work. Mean values or hazard ratios (HR) and their 95% confidence intervals. Hazard ratios represent the probability of failure at the trunk extension test before maximum time. ○ = crude values from univariate analyses, l = values adjusted for leisure-time physical activity, height, weight and smoking.
9. Model-predicted peak oxygen uptake (Vo2peak) of 4,071 males and 4,367 females at age 31 according to the frequency of participation in brisk exercise during leisure time. Results are from the health survey of the Northern Finland birth cohort of 1966. Vo2peak is also presented by different level of body mass index (BMI).