Physical activity has been incorporated as a part of the recommendations for food guides and dietary guidelines in several developed countriesReference Brooks, Butte, Rand, Flatt and Caballero1–3 due to its relationship to numerous chronic diseases, particularly obesityReference Hill and Wyatt4, coronary heart diseaseReference Kohl5, Reference Sundquist, Qvist, Johansson and Sundquist6, strokeReference Lee and Paffenbarger7, non-insulin-dependent diabetesReference Hu, Manson, Stampfer, Colditz, Liu and Solomon8, certain types of cancersReference Lee9 and all-cause mortalityReference Hu, Tuomilehto, Silventoinen, Barengo, Peltonen and Jousilahti10, Reference Blair and Brodney11.
Physical activity recommendations have undergone a few modifications in accordance with the outcomes of research related to which aspects of physical activity were related to health, the role of intensity or duration or type of physical activity, and on which aspects of health they influenced (cardiovascular, osteomuscular, metabolism, etc.). The difficulty in measuring habitual physical activity in the population has also added some uncertainties to the resolution of what the recommendations should consist ofReference LaPorte, Montoye and Caspersen12. Although the debate about the dose–response relationship between physical activity and health is still on-goingReference Kesaniemi, Danforth, Jensen, Kopelman, Lefebvre and Reeder13, Reference Blair, Cheng and Holder14, it appears that physical activity does not have to be of vigorous intensity to yield health benefits for the individual. Public health authorities recommend accumulating at least 30 min of moderately intense exercise on most days of the week to prevent the appearance of the majority of chronic diseases in the adult population15.
Compliance with such recommendations differs between countries. In the USA, data from the Behavioural Risk Factor Surveillance System showed that in 2001, 45% of adults were active at the reported recommended levelReference Macera, Ham, Yore, Jones, Ainsworth and Kimsey16. In Europe, the percentage of population that reported to be active during their leisure time varied from 92% in Finland to 41% in PortugalReference Martínez-González, Varo, Santos, De Irala, Gibney and Kearney17. In Spain, available data on physical activity come from different sources: the National Health Survey18, a periodical cross-sectional national representative survey and some regional or local surveys. According to data from the National Health Survey, in 2003, 34% of the adult Spanish population had a sedentary job and 58% of individuals did not realise any exercise during their leisure time. Regional information on physical activity comes from Nutritional Surveys developed in the communities of the Canary IslandsReference Serra Majem, Cabrera Leon and Sierra Lopez19, the Basque countryReference Aranceta, Pérez-Rodrigo, Marzana, Eguileor, González de Galdeano and Sáenz de Buruaga20, the Balearic IslandsReference Tur Marí and Obrador Adrover21, CataloniaReference Serra Majem, Ribas Barba, García Closas, Ramon, Salvador and Farran22, Reference Serra Majem, Ribas Barba, Salvador Castell, Castells Abat, Román Viñas and Serra23, ValenciaReference Vioque and Quiles24 and MadridReference Aranceta, Pérez Rodrigo, Amela and García Herrera25. Local data revealed that in the city of BarcelonaReference Dominguez-Berjon, Borrell, Nebot and Plasencia26 19% of the population did physical activity at least three times a week, 18% of the adults living in the city of MurciaReference Martínez-Ros, Tormo, Perez-Flores and Navarro27 did at least 2 h a week of vigorous physical activity, and 57% of males and 77% of females living in the city of PamplonaReference Elizondo-Armendariz, Guillen Grima and Aguinaga Ontoso28 were inactive during their leisure time. Information on trends is scarce as it is the information that covers all domains of physical activity such as household, leisure time, transportation or work-related physical activity. Trends data from the National Health Survey showed that the Spanish population has become less inactive during their leisure time (the percentage of the population that did no exercise during leisure time decreased from 63% in 1987 to 58% in 2003), but the percentage of people who did exercise regularly (several times per month) showed only a slight increase (9% in 1993, 11% in 2001)Reference Moreno, Sarría and Popkin29.
In Catalonia, the Catalan Nutritional SurveyReference Serra Majem, Ribas Barba, García Closas, Ramon, Salvador and Farran22 developed in 1992–93 in a representative sample of the population revealed that 59% of the population were inactive during leisure time, 20% of the population walked at least 30 min daily and 48% of the Catalan population had a sedentary job. The consecutive Health Plans for Catalonia30–34 developed periodically since 1991 stated, according to the World Health Organization (WHO) strategy ‘Health for All’, in the ‘Promotion for a positive attitude for health’ section, several objectives to improve the level of physical activity of the population through a specific campaign directed to the population. The purpose of the strategy was to improve the knowledge that not only the population but also the health professionals, the primary school teachers and the enterprises had about the relationship between physical activity and health. The 2002–03 Catalan Nutritional Survey included data which permits the analysis of trends of physical activity patterns of the population and compliance with some of the Catalan Health Plan objectives. The same questionnaire for evaluating the physical activity habits was used in the 1992–93 and 2002–03 surveys.
In the present study, the trends (1992–2003) of usual patterns of physical activity in a representative sample of the Catalan population are analysed.
Material and methods
The Catalan Nutrition Survey is a cross-sectional survey for the study of nutritional status, food habits and physical activity prevalence in a representative sample of the Catalan population. The target population consisted of all inhabitants living in Catalonia, and the sample population was derived from residents registered in the Spanish official population census. Two evaluations have been conducted within a 10-year interval with the same methodology: the ENCAT 1992–93Reference Serra Majem, Ribas Barba, García Closas, Ramon, Salvador and Farran22 survey and the ENCAT 2002–03Reference Serra Majem, Ribas Barba, Salvador Castell, Castells Abat, Román Viñas and Serra23 survey.
In ENCAT 1992–93 the theoretical sample was estimated to be 3000 subjects to guarantee a minimum of 100 individuals for each age and sex group. In all, 2757 individuals aged 6–75 years participated in the study (69% participation)Reference Serra Majem, Ribas Barba, García Closas, Ramon, Salvador and Farran22.
In ENCAT 2002–03, the theoretical sample size was set at 3300 individuals, taking into account an anticipated 70% participation rate, which would result in a sample of approximately 2310 individuals. Finally, 2160 individuals (participation rate 65%) aged 10 to 80 years participated in the ENCAT 2002–03 studyReference Serra Majem, Ribas Barba, Salvador Castell, Castells Abat, Román Viñas and Serra23.
The methodology of the study has been described elsewhereReference Serra Majem, Ribas Barba, García Closas, Ramon, Salvador and Farran22, Reference Serra Majem, Ribas Barba, Salvador Castell, Castells Abat, Román Viñas and Serra23, 35. Information on physical activity was provided by questions adapted from the WHO physical activity CINDI (Countrywide Integrated Noncommunicable Diseases Intervention) questionnaire36 used in the ENCAT 1992–93 and ENCAT 2002–03 surveys. Questions about type of physical activity at work, during leisure time and for walking to work (or walking to school or university) and habitual stair climbing were included. Occupational physical activity was classified as sedentary (sitting most of the time), moderate (walking most of the time, no vigorous activities), vigorous (walking most of the time and frequent vigorous activity) or highly active (doing vigorous activities most of the time). Leisure-time physical activity was classified according to its intensity as sedentary (reading, watching TV, etc.), moderate (walking, bicycling, etc.), vigorous (running, skiing, ball games, etc.) and regular physical exercise and training. The frequency of vigorous physical activity for at least 20–30 min was also reported. Vigorous physical activity was defined as that which increases perspiration or makes breathing harder than normal. The questionnaires were administered by trained dietitians and were included in the general questionnaire.
Data analysis
Data on physical activity at work, during leisure time, way of transport and regular stair climbing in ENCAT 1992–93 and ENCAT 2002–03 were calculated for comparison. The significance of the changes in the prevalences was calculated by χ 2 tests. Data were analysed using the statistical package SPSS for Windows version 12.0.
Results
The final sample for the analysis of physical activity patterns included 2344 individuals (1070 males and 1274 females) in the ENCAT 1992–93 survey and 2055 individuals (952 males and 1103 females) in the ENCAT 2002–03 survey. The subjects’ age ranged from 10 to 75 years.
Tables 1 and 2 show trends for males and females in terms of related activity at work, the time spent walking to work, way of transport and habitual stair climbing, leisure-time physical activity, and the frequency of vigorous physical activity for at least 20 min. An increase in the percentage of persons who have sedentary jobs is observed in all age groups except for younger individuals. The proportion of the population with sedentary work was 50% in 1992–93 and 53% in 2002–03 among men and 55% in 1992–93 and 59% in 2002–03 among women. There was a significant increase (P < 0.05) in the percentage of middle-aged females (45–65 years) that became more sedentary at work (from 38% to 51%).
Table 1 Trends in physical activity pattern in the male Catalan population (1992–2003)
Table 2 Trends in physical activity pattern in the female Catalan population (1992–2003)
The proportion of males who walked to work/school remained stable, 39% and 43% of males in 1992–93 and 2002–03, respectively, walking less than 30 min a day, with the youngest ones (those in the age group of 10 to 17 years) being the least active. Trends in females showed a significant decrease in the proportion of adolescents and young adults who walked to work/school: in the 1992–93 survey, 50% of 10–17-year-old females walked less than 30 min, the proportion increased to 61% in the 2002–03 survey (P < 0.05); for females aged 18–24 years, there was also an increased proportion of those who did not walk to work/school (P < 0.01).
The use of the car as the principal means of transport increased in both males and females. In males, the changes were statistically significant for the age groups from 10 to 17 years (increasing from 10% to 18%, P < 0.01) and from 25 to 44 years (from 59% to 64%, P < 0.01). In females aged 10 to 17 years the use of the car as a means of transport doubled in this time period (from 8% to 20%, P < 0.001). Significant increases were also observed in females from 18 to 24 (P < 0.01) years, and from 25 to 44 (P < 0.001) years. Only women aged 65–75 years increased their walking habits (from 13% to 38%, P < 0.05).
Habitual stair climbing increased among the population except for the older group where a decrease was seen (from 60% to 48% in 65–75-year-old males).
A slight decrease in the proportion of sedentary leisure-time activities for both males and females was observed (from 50% to 45% for males and from 67% to 63% for females), being significant in the group aged 45–64 years (P < 0.05 in males and P < 0.05 in females).
The frequency of vigorous physical activity showed an increase in the daily activity reported in males for almost all age groups: from 14% to 36% in 10–17-year-olds (P < 0.01), from 15% to 28% in those aged 18–24 (P < 0.01), from 12% to 20% in 25–44-year-olds (P < 0.05) and from 10% to 13% in 45–64-year-olds (P < 0.01). Referring to females, the oldest group showed an increase in the frequency of vigorous physical activity, both for those aged 45–64 years (P < 0.001) and for those aged 65–75 years (P < 0.001).
Discussion
Physical activity questionnaires are one of the most cost-effective methods for assessing physical activity in large-scale population studies. Even when they tend to overestimate the time and intensity of exercise, and to underestimate sedentary behaviours, they are fundamentally useful for assessing patterns, frequency and type of physical activityReference Livingstone, Robson, Wallace and McKinley37. In the present analysis, although the responses may have been subject to recall error, measurement error was not differential over time, as the questions were the same in both surveys. As such, the data showed in this report are a valuable tool for evaluating the evolution of physical activity habits in the Catalan population and the effectiveness of the campaigns promoting physical activity among the population.
An overall impression is that the Catalan population has become more sedentary at work and has decreased their habit of walking to work/school. On the other hand, individuals are slightly more active during leisure time. Although cross-country comparisons are difficult because of disparities between methodological aspects including the type of questionnaire used, the results shown are similar to other trend data published. In the USA, the Behavioural Risk Factor Surveillance System presented a decrease in the prevalence of leisure-time physical inactivity (from 30% to 24%) from 1994 to 200438. In Canada, leisure-time physical activity data from 1981 to 2000 showed an increase in the level of activity of adultsReference Craig, Russell, Cameron and Bauman39. In Eastern Finland, a 25-year trend in physical activity showed results similar to the Catalan population, with a reduction of the work-related physical activity, active commuting and an increase in high-intensity leisure-time physical activityReference Barengo, Nissinen, Tuomilehto and Pekkarinen40. Data from the Minnesota Heart Survey (1980–2000)Reference Steffen, Arnett, Blackburn, Shah, Armstrong and Luepker41 showed an increase in daily energy expenditure from lifestyle physical activity and leisure-time physical activity in both genders, and a decrease in workplace activity. In Spain, data on leisure-time physical activity available from the National Health Survey (1993–97) revealed that there was a decrease in the proportion of the Spanish population that was completely sedentary during their leisure time (from 55% to 46%)Reference Elizondo-Armendariz, Guillen Grima and Aguinaga Ontoso28. On the other hand, the data from our study contrasted with that from EnglandReference Prior, Erens and Primatesta42, SwedenReference Lindström, Isacsson and Merlo43 or AustraliaReference Bauman, Armstrong, Davies, Owen, Brown and Bellew44, where there was a decrease in the level of leisure-time activity practice of the population.
The questions related to work (type of activity and walking habits to work) included individuals from 65 to 75 years. As most of them are retired, the results have to be analysed with caution. Their reported work-related physical activity might be, in some cases, the physical activity related to non-paid work or leisure-time activities or volunteer related activities, etc.
The magnitude of changes in leisure-time physical activity is assessed by the number of days dedicated to carrying out vigorous physical activities for at least 20 min. Observed trends showed that both males and females increased their frequency of practice. Had the magnitude of such an increase represented greater net daily energy expenditure, the tendency would have been encouraging. However, to date and as reported in Finland, the observed increases of leisure-time energy expenditure do not counterbalance the declines seen in the energy demands of work activityReference Fogelholm, Mannisto, Vartiainen and Pietinen45, and as such this represents a decrease in total energy expenditure over time. In ENCAT 2002–03, 39% of the Catalan population (45% of males and 32% of females) reported conducting at least 2 days of vigorous physical activity for a minimum of 20 min. It has been previously reported that women tend to be less involved in vigorous-intensity physical activity than men, although it has also been observed that women are as active as men when all domains of physical activity are taken into accountReference Livingstone, Robson, Wallace and McKinley37. Any questionnaire that limits the study of physical activity patterns to leisure-time physical activity will underreport the values for women, as they tend to spend more time on household and family-care tasks, which implies a greater magnitude of moderate-intensity activities. On the other hand, recall and measurement error are greater for light- and moderate-intensity activity than for vigorous activityReference Shephard46. Although the description of the intensity of exercise may help to classify the effort realised by an individual, perceived effort is a personal sensation and older individuals may feel that the exercise they are doing is of more intensity than it really is. The observed increase in the number of women older than 45 years who exercise vigorously may be explained by the increase in the proportion of women of that age group who have changed their sedentary habits and have become active, independent of the intensity of the activity realised.
Nevertheless, the proportion of the Catalan population that has sedentary habits is still high (55% of the population, in the ENCAT 2002–03 analysis), and especially regarding females (63% of them having sedentary habits). The Catalan Health Plan published in 199130 stated the intention to reduce to 40% the proportion of Catalan individuals with sedentary habits by the year 2000, an objective which was not achieved in 2002–03. Most of the recommendations directed to the general population refer to increasing moderately intense physical activity, and emphasising the necessity to accumulate 30 min or more of moderately intense activity on most days of the week38 to achieve improvements on health status. Walking is an activity that can be easily incorporated and maintained in day-to-day life so as to achieve these recommendations. Another of the objectives of the Catalonia Health Plan for the year 2000 was to improve by 50% the proportion of people who walk at least 30 min a day. Unfortunately, the Catalan population does not seem to follow this guideline. The number of people who walk to work/school 30 min or more per day has decreased in a decade and 66% of the population do not walk or walk less than 15 min daily to go to work. An in-depth evaluation of the all-purpose walking habits of the population may have increased the proportion of people who comply with the daily recommendations. But data from the Catalan Health SurveyReference Roure, Vallbona, Tresserras, Taberner and Salleras47, a periodically developed survey to evaluate health status of the population of Catalonia since 1989, included some questions on physical activity that did not confirm this supposition. In 1989, 61% of the adult Catalan population walked at least 30 min daily, the proportion increased up to 77% in 1992–93 and decreased again to 61% in the 2002–03 surveyReference Roure, Vallbona, Tresserras, Taberner and Salleras47.
It is of utmost importance to address the promotion of physical activity among the population. Until now, the campaigns to decrease sedentary habits among the population in Catalonia had focused mostly on individuals instead of on the community. Lately, much effort has been put into increasing the environmental possibilities to facilitate the opportunities to walk, bike and use public transport among the population (increasing the availability of bike and walking lanes in the big cities). Similar increased opportunities to walk or exercise should be made at the workplace as well. The literature provides evidence that multidisciplinary action involving the family, the environment, the school, etc. are the most efficient to increase the physical activity habits of a populationReference Kahn, Ramsey, Brownson, Heath, Howze and Powell48. Special input should be made at the workplace. It is time to act on these fronts to face the epidemics of inactivity. Otherwise, it will be of great difficulty to reverse the trend of increasing overweight and obesity prevalence in the Spanish and Catalan population.
Acknowledgements
Sources of funding: This work was made possible by financing from the General Division of Public Health of the Generalitat of Catalonia’s Department of Health, through a research agreement with the Fundación para la Investigación Nutricional (Nutrition Research Foundation).
Conflict of interest declaration: None of the authors had any conflicts of interest in connection with this study.
Authorship responsibilities: BRV was responsible for the interpretation of physical activity data and the writing of the paper, LSM was director of the study and revised the paper providing expert advice on data interpretation and discussion of the paper, LRB was responsible for the statistical analysis and revised the paper providing expert advice on data interpretation, ERC, CC, CV and AP provided expert advice on data interpretation and in the discussion of the paper.
Guarantor: Lluís Serra-Majem.
Acknowledgements: Special acknowledgement is made to all those persons who were interviewed, and whose collaboration made the realisation of these surveys possible.
Research Group on the Evaluation and Monitoring of the Nutritional Status in the Catalan Population: Lluís Serra-Majem, Director (University of Las Palmas de Gran Canaria); Lourdes Ribas-Barba, Coordinator (FIN – Nutrition Research Foundation, Barcelona Science Park); Gemma Salvador (Generalitat of Catalonia); Conxa Castell (Generalitat of Catalonia); Blanca Román – Viñas (FIN, Barcelona Science Park); Jaume Serra (Generalitat of Catalonia); Lluís Jover (University of Barcelona); Ricard Tresserras (Generalitat of Catalonia); Blanca Raidó (FIN, Barcelona Science Park); Andreu Farran (CESNID, University of Barcelona); Joy Ngo (FIN, Barcelona Science Park); Mari Cruz Pastor (Hospital Germans Trias i Pujol, Badalona); Lluís Salleras (University of Barcelona); and Carmen Cabezas, Josep Lluís Taberner, Salvi Juncà, Josep Maria Aragay, Eulàlia Roure, Gonçal Lloveras Vallès († 2003), Antoni Plasencia (Generalitat of Catalonia).
