ECSS Paris 2023: CP-MH01
INTRODUCTION: Physical inactivity increases the risk of dementia [1]. Previous studies have focused on total sedentary time, without accounting for how it accumulates throughout the day. Frequent sedentary breaks have been associated with improved glycemic and blood pressure control [2,3], both of which are recognized risk factors for dementia. In this study, we examined the association between frequency of sedentary breaks and cognitive function in Japanese community-dwelling older adults. METHODS: In this cross-sectional study, 952 community-dwelling older adults aged ≥65 years participated and wore a triaxial accelerometer for 10 consecutive days. Activity intensity was derived from accelerometer data. Sedentary behavior was defined as ≤1.5 METs, and sedentary breaks were identified as transitions from sedentary behavior to activity >1.5 METs. Participants were categorized into quartiles (Q1–Q4) according to the daily frequency of sedentary breaks. Cognitive performance was assessed using a battery of tests, including the Mini-Mental State Examination, the Logical Memory I and II subtests of the Wechsler Memory Scale–Revised, and the Trail Making Test A and B (TMT-A, TMT-B). Cognitive performance was compared across quartiles. RESULTS: In men, a higher frequency of sedentary breaks was significantly associated with better performance on TMT-A and TMT-B after adjustment for age, waking time, total sedentary time, and light-intensity physical activity (TMT-A: p for trend = 0.02; TMT-B: p for trend = 0.04). In women, a higher frequency of sedentary breaks was significantly associated with better performance on TMT-A (p < 0.01 for trend). CONCLUSION: A higher sedentary break frequency in daily life was associated with better TMT performance in community-dwelling older adults. These associations persisted even after adjusting for total sedentary time and light-intensity physical activity, suggesting that the frequency of sedentary breaks reflects a different aspect of sedentary behavior. These results suggest that the frequency of sedentary breaks may represent an important behavioral indicator of cognitive performance in older adults. Reference 1. Livingston G, et al., Lancet., 2024 2. Hartman SJ, et al., Circulation., 2025 3. Duran AT, et al., Med Sci Sports Exerc., 2023
Read CV Saki HashimotoECSS Paris 2023: CP-MH01
INTRODUCTION: Skeletal muscle satellite cells are essential in muscle fiber regeneration, repair, and growth. Aging is accompanied by specific loss of type II muscle fiber size and associated satellite cell content and function. Muscle fiber capillarization has been suggested to play a key role in satellite cell function. We assessed whether 8 weeks of aerobic exercise training, to increase muscle fiber capillarization, improves the acute type II muscle fiber satellite cell response to a single bout of resistance exercise in healthy older adults. METHODS: In a randomized parallel design, n=26 healthy older (70±5 y) adults participated in 8 weeks of aerobic exercise training (AER, n=14), 3 times per week for 45 min at 65% VO2peak or no-exercise control (CON, n=12). Aerobic capacity (VO2peak tests on cycling ergometer) and body composition (DXA-scan) were assessed at baseline and following 8 weeks of AER or CON intervention. Resting vastus lateralis muscle biopsies were collected at baseline and following the 8-week AER or CON intervention. To assess the acute satellite cell response, two additional biopsies were obtained at 24 and 48 h following a single bout of resistance exercise after the 8-week AER or CON intervention. Immunohistochemistry was used to assess type I and type II muscle fiber size, capillarization, and satellite cell content. Data were analyzed by two-way repeated-measures ANOVA. Post-hoc testing was performed in case of a significant time x treatment interaction effect. Statistical significance was set at P<0.05. All data are expressed as mean±SD. RESULTS: Aerobic exercise training increased VO2peak (9±6%, P<0.05), with no changes in leg lean mass. VO2peak and leg lean mass remained unchanged in response to the 8-week CON condition. Whereas type I muscle fiber size remained unchanged, a main effect of time (P<0.05) was observed for type II muscle fiber size, which was mainly driven by hypertrophy observed in the AER group (24±48%, P<0.05). Type I (33±25%, P<0.05) and type II (37±40%, P<0.05) muscle fiber capillarization increased in the AER group, with no changes in the CON group. Aerobic exercise training increased type I (97±65%, P<0.05), but not type II muscle fiber satellite cell content. Type I and II muscle fiber satellite cell content remained unchanged in the CON group. The acute type I and II muscle fiber satellite cell response was not different between the AER and CON group (interaction effects, P>0.1) at 24 and 48 h following the single bout of resistance exercise. CONCLUSION: Aerobic exercise training increases type I and II muscle fiber capillarization and satellite cell content in type I muscle fibers in healthy older adults. The type II muscle fiber satellite cell response to an acute bout of exercise is not modified by prolonged aerobic exercise training. An increase in muscle fiber capillarization does not improve post-exercise muscle satellite cell function in healthy older adults.
Read CV Milan BetzECSS Paris 2023: CP-MH01
INTRODUCTION: Low physical fitness is related with the risks of fall, sarcopenia and cardiovascular disease in older adults [1,2]. Exercise snack (ES), which is consisted of short bouts of high-intensity exercise spread across the day, is one of the most time-efficient exercises to improve physical function in older adults [2,3]; however, it is not clear the effects of ES on cardiorespiratory fitness (CRF) and muscle strength in older adults. Given that high-intensity interval training improved maximal oxygen uptake and muscle strength in young adults [4], aerobic-based (AES) and resistance-based ES (RES) may improve CRF and muscle strength. However, this issue has not been addressed. This study compared the effect of AES and RES on physical fitness in older adults. METHODS: 27 community-dwelling older adults were participated and randomly assigned the control (CON: n=9, 73.4±5.7 years, Body mass index [BMI]; 22.5±3.1 kg/m2), AES (n=7, 72.4±4.7 years, BMI; 23.4±3.1 kg/m2) and RES groups (n=11; 72.0±5.0 years, BMI; 23.0±2.6 kg/m2). Participants performed 3 bouts of 60-s exercise (AES: step exercise, RES: half-squat) followed by a 60-s rest, twice a day, 3 days a week, over 8 weeks. Body composition, isometric maximal voluntary contraction (MVC) of leg extension, gait speed, the Timed Up and Go test (TUG) and the 6-min walk test were measured at the baseline (Baseline), 4 weeks (Middle) and 8 weeks (Post). RESULTS: Compared with the Baseline, gait speed (AES: +0.16 m/s; RES: +0.12 m/s; p=0.009, d=0.36), the TUG (AES: -1.0 s, p=0.002, d=0.81; RES: -0.5 s, p=0.010, d=0.77) and MVC (AES: +5.4 kg, p=0.004, d=0.45; RES: +9.5 kg, p<0.001, d=1.18) were improved at the Post in the AES and RES groups. Compared with the CON group, the TUG (AES: -1.2 s, p=0.001, d=0.97; RES: -1.1 s, p=0.005, d=1.14) and MVC (AES: +6.5 kg, p=0.017, d=0.59; RES: +12.0 kg, p<0.001, d=1.37) at the Post were improved in the AES and RES groups. No significant differences between and within groups were observed for body composition and the 6-min walk test (p>0.05). CONCLUSION: This study revealed that AES and RES significantly improved gait speed, the TUG and MVC, suggesting that ES, irrespective of whether comprised aerobic-base or resistance-base, may prevent fall and sarcopenia in older adults [1]. However, AES and RES did not improve the 6-min walk test, which differed from the previous results that the 8 weeks high-intensity interval training improved the 6-min walk test in older adults [5]. This may be due to shorter duration of ES since the meta-analysis suggested that an improvement in maximal oxygen uptake in older adults was required longer exercise duration (i.e., 20 to 40 min) when performing high-intensity interval training [6]. In conclusion, AES and RES improved gait speed, the TUG and MVC but not the 6-min walk test in older adults. References: 1. Faragala et al., 2019; 2. Rodríguez et al., 2025; 3. Fyfe et al., 2022; 4. Ramos-Campo et al., 2021; 5. Wu et al., 2021; 6. Chu et al., 2026.
Read CV Ryosuke MutoECSS Paris 2023: CP-MH01