Association between physical fitness and executive functions in cognitively healthy female older adults: a cross-sectional study.

Cardiovascular endurance and muscular fitness seem to impact specific cognitive components in older females. However, it remains uncertain whether these relate to executive functions or if these correlations are limited to specific physical fitness indicators. This study aimed to determine the association between specific physical fitness components and executive functions in community-dwelling older females. Thirty-five cognitively healthy community-dwelling older females (71.5 ± 5.7 years) underwent a series of physical fitness tests. These included the handgrip strength test (HGT), the 6-min walk test (6MWT), the 8-foot up-and-go test (8FUGT), and the chair stand test (CST). Participants also completed trail A and trail B of the cognitive trail making test. Results showed that trail B reaction time had a negative association with both HGT (r = - 0.502; p = 0.002) and 6MWT (r = - 0.543; p < 0.001). Together, the HGT and 6MWT results explained 39% of the variation in trail B reaction times: HGT accounted for 18% and 6MWT for 21%. Better scores on the 6MWT and HGT-but not on the 8FUGT and CST-correlated with enhanced executive function in cognitively healthy community-dwelling older females. The results of this study underscore the importance of specific physical assessments, like the 6MWT and HGT, as potential indicators of executive function, offering targeted strategies for maintaining cognitive health in aging females.

Association between changes in habitual stepping activity and cognition in older adults.

Advancing age is associated with declines in cognitive function. Although physical activity is thought to protect against this decline, it is unclear how a short-term uptake in daily steps or a decline in day-to-day step variability may contribute to cognition among older adults. We tested associations between changes in step counts, day-to-day step variability and executive cognitive functions among older adults taking part in a physical activity intervention. Thirty-seven older adults (33 females; 71.4 ± 6.3 years) completed a 10-week personalized physical activity intervention. Participants wore a Fitbit to measure daily step counts throughout the study. They also completed a computerized Stroop task before and after the intervention. Average step counts and step count variability via average-real-variability (ARV) were determined. Compared to pre-intervention, step counts increased (p < 0.001) and step variability decreased post-intervention (p = 0.04). Models describing the changes in step counts and ARV over the 10-weeks were cubic (both, p < 0.04). Reaction times during the simple (p = 0.002) and switching (p = 0.04) conditions were faster post-intervention. Change in step variability was positively associated with the change in reaction time for the switching condition (ß = 0.029, p = 0.002). On average, a reduction in day-to-day step variability was associated with improvements in cognitive flexibility.

Frailty is associated with worse executive function and higher cerebral blood velocity in cognitively healthy older adults: a cross-sectional study.

Frailty is characterized by an increased vulnerability to adverse health events. Executive function impairment is an early sign of progression towards cognitive impairments. Whether frailty is associated with executive function and the associated mechanisms are unclear. We test the hypothesis that higher frailty is associated with worse executive function (Trail Making Test) and if aerobic fitness, prefrontal cortex oxygenation (ΔO2Hb), or middle-cerebral artery velocity (MCAv) impact this association. Forty-one (38 females) cognitively health older adults (70.1 ± 6.3 years) completed a Trail task and 6-min walk test. Prefrontal cortex oxygenation was measured during the Trail task (via functional near-infrared spectroscopy) and MCAv in a sub-sample (n=26, via transcranial Doppler). A 35-item frailty index was used. Frailty was independently, non-linearly related to trail B performance (Frailty2: ß=1927 [95% CI: 321-3533], p = 0.02), with the model explaining 22% of the variance of trail B time (p = 0.02). Aerobic fitness was an independent predictor of trail B (ß=-0.05 [95% CI: -0.10-0.004], p = 0.04), but age and ΔO2Hb were not (both, p > 0.78). Frailty was positively associated with the difference between trails B and A (ß=105 [95% CI: 24-186], p = 0.01). Frailty was also associated with a higher peak MCAv (ρ = 0.40, p = 0.04), but lower ΔO2Hb-peakMCAv ratio (ρ = -0.44, p = 0.02). Higher frailty levels are associated to worse Trail times after controlling for age, aerobic fitness, and prefrontal oxygenation. High frailty level may disproportionately predispose older adults to challenges performing executive function tasks that may manifest early as a compensatory higher MCAv despite worse executive function, and indicate a greater risk of progressing to cognitive impairment.

Outdoor gyms and physical function: A cross-sectional comparative study between active and sedentary older adults.

Outdoor gyms (OG) are public places designed for physical activity, especially for older adults. This is a cross-sectional study that aimed to compare morphofunctional characteristics of sedentary and active older adults regarding OG. The participants consisted of 194 older people divided into three groups: sedentary (n = 76, mean age = 70.5 ± 6.4 years, 38.7% male); OG + walking (n = 86; mean age = 69 ± 6.1 years; male 50.6%); and OG (n = 32; mean age = 70.3 ± 8.3 years; male 56.3%). Socioeconomic and morphofunctional characteristics, anthropometric measurements, body composition, and functional tests were collected. For comparison among groups ANOVA, for categorical variables the chi-square test or Fisher's exact test, and to verify factors related to gait speed logistic regression were used. We found that sedentary older adults had lower educational level and lower prevalence of polypharmacy. OG + walking participants had lower waist circumference and fat percentage, and better gait speed. Older people in the OG + walking were less likely to show gait difficulty (i.e., <1.0 m/s) in reference to the sedentary group. In addition, strength and better performance on the Timed Up and Go were also associated with gait speed >1 m/s. It is understood that the higher volume of physical activity performed by OG + walking may be one of the reasons why they obtained better indicators in health aspects. The findings, especially regarding the characterization of profiles of older adults who use OG, leads to the definition of public policies aimed at the real needs of this public.

Isokinetic strength of shoulder rotator muscles in powerlifters: correlation between isometric and concentric muscle actions.

BACKGROUND: Isokinetic strength has been useful to assess muscle function related to sports and prevent injuries. The present study measured the isokinetic isometric and concentric shoulder rotators strength, agonist/antagonist ratio, and examined the relationships between isometric and concentric peak torque, and agonist/antagonist ratio in powerlifters compared to a control group. METHODS: The participants were divided into two groups: powerlifters group (N.=14) and physically active group (N.=9). Participants' were evaluated on isokinetic dynamometer for isometric, and concentric (two velocities, 60°/s and 180°/s) strength of shoulder external (ER) internal rotation (IR). Isometric contractions lasted 10 seconds, and concentric modes were 5 repetitions. RESULTS: Bilateral significant differences, between dominant and non-dominant side, were found in ER peak torque at isometric mode in powerlifters group (P=0.021). Powerlifters showed higher IR peak torque at isometric mode in dominant (P=0.040) and non-dominant side (P=0.014) than physically active group. Pearson correlations between isometric peak torque and concentric velocities ranged between 0.49 and 0.89 for powerlifters group, and between 0.73 and 0.93 for physically active group. For agonist/antagonist ratio, pearson correlation ranged between 0.47 and 0.83 for powerlifters group, and between 0.48 and 0.86 for physically active group. CONCLUSIONS: The bilateral differences in ER movement at isometric mode in powerlifters suggest that exercises for shoulder rotators must be included on training for joint safety and balance between sides despite isometric shoulder rotators strength in powerlifters was higher than physically active individuals. Results presented positive correlation between both muscle actions, isometric and concentric, in peak torque and agonist/antagonist ratio.

Correlation between handgrip and isokinetic strength of shoulder muscles in elite sitting volleyball players.

The aim of this study was to examine the relationships between isometric handgrip (HG) strength and isokinetic strength data of the glenohumeral rotator muscles. Twelve (Female = 50%) Brazilian Sitting Volleyball (SV) national team players volunteered. Measures of maximal grip strength were obtained by a HG dynamometer Jamar® and isokinetic measures of peak torque (PT) and total work (TW) during shoulder rotations movements were obtained with a Biodex isokinetic dynamometer at speed of 60°/s and 180°/s. Pearson correlation coefficients between isometric HG and isokinetic strength data ranged between 0.23 and 0.72 for the PT and between 0.3 and 0.76 for the isokinetic TW. Results presented positive relationships between HG isometric strength and isokinetic strength of external rotators of the shoulder in SV players. We can suggest that in the absence of isokinetic dynamometers, HG isometric strength measurements could be used to measure strength levels of the external rotator muscles of elite SV players' shoulder, particularly in the TW values.

Asymmetry in glenohumeral muscle strength of sitting volleyball players: an isokinetic profile of shoulder rotations strength.

BACKGROUND: Sitting volleyball (SV) is a popular Paralympic game, in which shoulders of SV players are overloaded continuously during play. Nevertheless, shoulder girdle muscle function has never been measured in this population yet. The objective of this study was to investigate the dominant and non-dominant strength profile of male and female elite SV players on a glenohumeral level. METHODS: A total of 13 Brazilian SV national team players volunteered to participate in this study (male: N.=6, age 32.8±4.1 years, body mass 83.2±19.4 kg, seated height 1.47±0.04 m; female: N.=7, age 32.8±4.1 years, body mass 80.1±17.9 kg, seated height 1.36±0.05 m). A Biodex dynamometer was used to measure internal rotation (IR) and external rotation (ER) of the glenohumeral muscle strength at 60°/s and 180°/s velocities in a concentric/concentric mode. RESULTS: It was observed that male SV players were stronger than the female players at both upper limbs. Concerning the side effects, significant differences were found for IR at 60°/s velocity (F=7.55, P=0.02) and ER at 180°/s velocity (F=5.91, P=0.03), with higher values on the dominant limb in comparison to the non-dominant limb for both the male and female players. There were significant gender differences for the IR inter-limb asymmetry at 180°/s velocity, with a greater asymmetry between both shoulders in the male players compared to the female players, preference for the dominant side in both groups. CONCLUSIONS: The SV players have an asymmetrical rotational strength profile. As muscular imbalance is a common injury pattern among overhead players. The findings of this study may assist the SV coaches and physiotherapists for evaluation and training of strength of the ER and IR shoulders of these players.