To evaluate the associations between physical fitness levels, health related quality of life (HRQoL) and sarcopenic obesity (SO) and to analyze the usefulness of several physical fitness tests as a screening tool for detecting elderly people with an increased risk of suffering SO. Cross-sectional analysis of a population-based sample. Non-institutionalized Spanish elderly participating in the EXERNET multi-centre study. 2747 elderly subjects aged 65 and older. Body weight, height and body mass index were evaluated in each subject. Body composition was measured by bioelectrical impedance. Four SO groups were created based on percentage of body fat and relative muscle mass; 1) normal group, 2) sarcopenic group, 3) obesity group and 4) SO group. Physical fitness was evaluated using 8 tests (balance, lower and upper body strength, lower and upper body flexibility, agility, walking speed and aerobic capacity). Three tertiles were created for each test based on the calculated scores. HRQoL was assessed using the EuroQol visual analogue scale. Participants with SO showed lower physical fitness levels compared with normal subjects. Better balance, agility, and aerobic capacity were associated to a lower risk of suffering SO in the fittest men (odds ratio < 0.30). In women, better balance, walking speed, and aerobic capacity were associated to a lower risk of suffering SO in the fittest women (odds ratio < 0.21) Superior perceived health was associated with better physical fitness performance. Higher levels of physical fitness were associated with a reduced risk of suffering SO and better perceived health among elderly. SO elderly people have lower physical functional levels than healthy counterparts.

The aims of the present study were (1) to describe the changes in physical fitness during an 8 year follow-up in a large sample of Spanish adults aged 65 or over that are initially engaged in organized physical activity (OPA), (2) to compare fitness changes according to different age groups (65 to 69 vs. 70 to 74 vs. ≥75 years-old), (3) to evaluate the independent and combined effects of changes in OPA engagement and sitting time (ST) on physical fitness. A total of 642 (147 males) non-institutionalized over 65 years-old participants completed the EXERNET battery fitness tests and completed a validated questionnaire from which information regarding OPA and ST were collected. All participants completed evaluations in 2008–2009 and in 2016–2017. An impairment of fitness-related variables happens after 65 years of age in both males and females, with the older participants (≥75), showing the largest decreases. Males who continued performing OPA demonstrated lower decreases in balance, leg flexibility and agility when compared to those who stopped performing OPA during the follow-up. Females who continued performing OPA demonstrated lower decreases of all variables except for balance when compared to those who stopped performing OPA during the follow-up.

The increase in life expectancy occurred during the last decades has resulted in a growth of the elderly population, being estimated that a third of the Spanish population will be elderly (> 65 years) in the year 2050. Human aging involves many changes, such as a variation in body composition. Different factors work together leading to an increase in fat mass, decreased muscle mass and reduced bone mass among seniors. These characteristic changes among elderly people may lead to suffer several diseases such as obesity, sarcopenia and osteoporosis and may result in decreased quality of life, increased dependence and increased risk of mortality in this population. In the late 90's, "sarcopenic obesity" was a concept that emerged in order to define those people who simultaneously have an excess of body fat and a significant loss of muscle mass. Recently, for the first time in Spain (the elderly EXERNET multi-centre study), it has been shown that the prevalence of sarcopenic obesity in a representative sample of non-institutionalized seniors reaches values of 15%.

Background: As the population is getting older, physical activity promotion becomes a good strategy to increase quality of life in the elderly; but genetic condition also plays an important role. The purpose of this study was to examine the association of the ACTN3 R577X polymorphism with physical fitness and muscle mass in physically active older women. Methods: A cross-sectional study was performed with two groups of older women who practiced physical exercise regularly. The first cohort comprised 164 women (age 69.7 ± 3.2 years) and the second cohort 131 women (age 78.5 ± 3.0 years). The main outcome measures were anthropometric measures with assessment of sarcopenia and sarcopenic obesity, self-reported physical activity EXERNET questionnaire (EEPAQ), evaluation of physical fitness (muscle strength and flexibility test), and ACTN3 genotyping. Results: Women above 75 years old with allele R presented a higher risk of experiencing sarcopenia compared to ACTNR XX homozygous women (odds ratio 0.356, 95% confidence interval 0.139–0.915, p = 0.026). Furthermore, statistically significant differences were found in the chair stand test (p = 0.04), as well as in the sit and reach test (p = 0.01), with better results for women below 75 years old with the ACTN3 XX genotype. Conclusions: Sarcopenia and physical fitness show differences based on the ACTN3 R577X genotype in active older women.

The purpose of this study is to analyze the effect of two genetic polymorphisms, ACTN3 R577X, and ACE I/D, on physical condition in a sample of active older women after a two-year training period. The sample was composed of 300 healthy women over the age of 60 who underwent a two-year training program. Adapted tests from the Senior Fitness Test were used. The genotyping of the polymorphisms was obtained from the participants’ DNA via buccal swabs. The analysis of the ACE polymorphism did not reveal differences between genotypes. The analysis of the R577X polymorphism showed a favorable effect for the ACTN3 XX genotype in tests for leg strength (p: 0.001) after training, compared to the other genotypes, and also in the analysis of the combined effect of the polymorphism (ACE II + ACTN3 RX/XX). The intragroup effect revealed an improvement in arm strength for carriers of the X allele after 24 months of training (p < 0.05). The endurance values significantly worsened in all study groups. Conclusions: The R577X polymorphism of ACTN3 may have an important role in capacities related to muscle strength, providing a beneficial effect for carriers of the X allele.