Vol.:(0123456789) 1 3 Quality of Life Research https://doi.org/10.1007/s11136-019-02252-3 Does fitness attenuate the relationship between changes in sitting time and health‑related quality of life over time in community‑dwelling older adults? Evidence from the EXERNET multicenter longitudinal study O. López‑Torres 1,12  · B. del Pozo‑Cruz 2  · B. Maroto‑Sánchez 1  · S. Vila‑Maldonado 3,4  · A. Gómez‑Cabello 4,5,6,7,8  · M. Martín‑García 3  · A. González‑Agüero 6,7,8,9  · N. Gusi 4,10  · L. Espino 4,11  · J. A. Casajús 6,7,8  · M. González‑Gross 1,8  · I. Ara 3,4  · R. Pedrero‑Chamizo 1 Accepted: 21 July 2019 © Springer Nature Switzerland AG 2019 Abstract Objective To assess the relationship between fitness levels and components, sitting time and health-related quality of life (HRQoL), over time among community-dwelling older adults. Methods Three different sitting trajectories were calculated: (i) no change; (ii) decrease; and (iii) increase in ST, between baseline and follow-up. Fitness was assessed using the aerobic capacity, upper and lower limb strength, and total fitness. Participants were classified into higher (75th percentile or above) or lower (below 75th percentile) fitness levels, using the fitness tests. HRQoL scores at follow-up were compared to the three different sitting time trajectories within and across both the higher and the lower fitness groups for each of the three fitness indexes. Results Greater HRQoL scores were observed in those participants that decreased their ST as compared with those increas- ing their sitting time over time for participants classified in the lower end of their aerobic capacity or total fitness index. No differences were detected in HRQoL scores in people classified in the higher fitness level group for any of the fitness indexes. Participants that increased or did not change their sitting time and who were classified in the higher fitness end of aerobic capacity and total fitness index self-reported higher HRQoL scores when compared with those in the lower fitness end. Conclusion Increased sitting time over time is associated with poorer HRQoL in older adults. Higher fitness levels could help attenuate the negative impact of sitting over time. Keywords Physical condition · Sedentary behavior · Well being · Elderly Introduction Health-related quality of life (HRQoL) is a multi-dimen- sional construct that reflects the self-perception of the impact of health status on the quality of life of an individual [1]. Clinicians and public health officials have used HRQoL to measure the effects of chronic diseases, treatment, and disability. In addition, HRQoL has been used to monitor the general health at population level or as a key measurement in the planning and decision-making processes of health- related policies [2, 3]. With an increasing aging popula- tion, and the associated rises of chronic diseases and costs, improving HRQoL is a priority [4]. There is now compelling experimental evidence [5, 6], reviews and meta-analyses [7] providing solid arguments that physical activity [8, 9], most likely through physical fit- ness [10, 11], is a cost-effective health strategy in improving the HRQoL of the older population [12]. Nonetheless, physi- cal activity levels and physical fitness levels are worryingly low among the older population in Spain [13]. On the other hand, sedentary behaviors, a group of wak- ing behaviors characterized by very low energy expenditure that occur while sitting or lying down, in combination with the lack of moderate-to-vigorous physical activity (MVPA), O. López-Torres and B. del Pozo-Cruz contributed equally to this work. * O. López-Torres olga.lopez@upm.es Extended author information available on the last page of the article