ECSS Paris 2023: CP-PN03
INTRODUCTION: Muscle function recovery following exercise-induced damage (EIMD) is thought to be influenced by individual strength, mobility and activity level. However, evidence in older adults remains limited. This study investigated whether baseline muscle function, mobility, and habitual physical activity predict recovery following an unaccustomed eccentric exercise bout in healthy older adults. METHODS: Thirty older adults (70.9 ± 4.0 years, 11 males, 19 females) completed a single bout of eccentric exercise (10 sets of 10 repetitions; 1 s concentric, 1 s hold, 3 s eccentric). Muscle soreness (DOMS), countermovement jump (CMJ), and maximal voluntary contraction (MVC) were assessed pre- and post-exercise (24, 48, and 72 h). Baseline measures included handgrip strength, a 4-meter walk test, a chair rise test, one-repetition maximum (1RM), and Skeletal Muscle Mass Index (SMI). Physical activity was categorized using the International Physical Activity Questionnaire (IPAQ). Recovery was quantified as the area under the curve (AUC) of the percent loss from baseline using the trapezoidal method. Spearman correlations and Kruskal-Wallis tests assessed associations between AUC values, baseline measures, and IPAQ activity levels. RESULTS: Following exercise, MVC loss was 12.05% at 24 h and recovered by 48 h. CMJ force loss peaked at 48 hours, while CMJ height, power, and velocity continued to decline through 72 hours. DOMS peaked at 24 hours across all conditions (standing, sitting down, and standing up). No significant differences were observed between men and women in any recovery metric. Spearman’s correlations revealed that AUC-MVC was negatively associated with 1RM (ρ = -0.45, p = 0.015) and handgrip strength (ρ = -0.39, p = 0.036). CMJ Velocity (ρ = 0.39, p = 0.039) and Power (ρ = 0.38, p = 0.042) losses were positively correlated with age. Additionally, individuals classified as moderately active according to the IPAQ showed significantly better CMJ power recovery than those with low activity levels (p = 0.031). CONCLUSION: Older individuals with higher baseline strength and moderate physical activity may be more resistant to functional impairments following EIMD, with baseline functionality potentially predicting recovery kinetics. Greater strength in active individuals could also support better recovery. Given the ongoing study and sample size limitations, these findings should be interpreted with caution.
Read CV Donna LiECSS Paris 2023: CP-PN03
INTRODUCTION: Evidence suggesting that acute exercise enhances executive functions predominantly arises from studies focused on aerobic exercise. It remains unclear whether strength physical exercises, such as intermittent isometric handgrip exercises, affect executive functions in young and older adults. We examined the dose-effect response of several physical loads and their potential effect on perceptual cortex hemodynamics effects. METHODS: Using a crossover design, 46 participants completed intermittent isometric handgrip exercise using three modalities concerning repetition or duration 1): 4 repetitions of 2 min of 30% of maximal voluntary contraction (MVC) with 3 min of recovery 2) with 1 minute of recovery and 3) 8 repetitions of 2 min of 30% of MVC with 3 min of recovery and 4) a control condition in a randomized order. Before and after each condition, they performed a Stroop task assessing inhibition and flexibility processes. Perceptual, cognitive difficulty and prefrontal cortex oxygenation were measured during both tasks. RESULTS: For the Stroop task, we found a greater good response only for the condition 4 repetitions with 3 minutes of recovery of flexibility task. We found no effect of exercise on inhibition task. This was accompanied by a lower perceived difficulty of the task and lower physical perceived physical effort only on this condition. Although hemodynamic changes have been observed, they do not seem to explain the cognitive changes. CONCLUSION: Acute isometric handgrip exercise with adequate load improves flexibility, but the inhibition remains unaffected. This effect of the load is accompanied by an improved perceived difficulty of physical and cognitive effort.
Read CV Amani MechraouiECSS Paris 2023: CP-PN03
INTRODUCTION: Metabolic flexibility (MF), the ability to adapt and adjust substrate oxidation relative to substrate availability, has been recently linked to the autonomic function in postmenopausal women (2), likely due to the vagus nerve activity at the hepatic level (1). Autonomic function at rest, assessed through Heart Rate Variability (HRV), showed to be associated with MF indicators such as maximal fat oxidation MFO or the final lactate in a FATmax test (RER=1.07) (2). However, the relationship between the cardiovascular variables fat oxidation and HRV at rest are not well known and the current study will study this. METHODS: Forty-five menopausal active women (67.9±5.3 years; 65.8±11.5 kg; 40.3±4.2 kg muscle mass) performed a resting metabolic rate test in supine position. Basal metabolic rate (BMR) and MFO were assessed by indirect calorimetry using a K5 metabolic cart (Cosmed, Rome, Italy) for 30 minutes. HRV was simultaneously registered by means of a H10-polar band and the Sensor Polar Logger App. The first 5 were discarded. Participants arrived at the same time (8:30 a.m. & 10:00 a.m.), after 12h overnight fasting, preceded by a standardised dinner (50% carbohydrate content) the previous day. Prior to recording, they remained in a supine position for a period of 15 minutes, relaxed and with eyes closed. After normality test, Spearman and Pearson correlations were applied. RESULTS: BMR was low (990±270 kcal/day), despite a larger RER (0.79±0.05) and fat contributed the total energy expenditure (69.9±15.7% fat; 0.072±0.031 g/min; 1.69 mg/min/kgFFM) compared with similar sample (3). HRV revealed a basal autonomic steady state both in linear-indexes root mean square of successive differences between beats (RMSSD, 25.8±18.2 ms), as in non-linear indicators SD1 (18.3±12.9 ms), sample entropy (SampEn, 1.73±0.20) or detrended fluctuation analysis α1 (DFAα1, 0.95±0.21). An association between FATox (both in absolute and relative units) with the main autonomic variables: parasympathetic (PNS) index (r=0.56; 0.58), low frequency power (r=0.37; 0.36), RMSSD (r=0.31; 0.32) and SD1 (r=0.31; 0.32) was confirmed by the significant, positive and moderate correlation. BMR was also significantly, positively and moderately associated with PNS index (r=0.51), pnn50 (r=0.32), RMSSD (r=0.31) and SD1 (r=0.31), instead of LF which was not associated with BMR. DFAα1 and SampEn did not show any significant associations. CONCLUSION: Vagal activity assessed through HRV confirms to be associated with basal metabolic rates and Fatox rates at rest i.e. metabolic flexibility. Our data support the hypothesis linking fat oxidation and vagal activity, thus underlining the importance of HRV in the assessment of cardiovascular (both, metabolic and autonomic) health. References: 1. Matsubara et al. Neuropharmacology; (2022) 2. Monferrer-Marín et al. European Journal of Applied Physiology; (2024) 3. Maghbooli, Z., et al. BMC womens health; (2022)
Read CV Jordi Monferrer MarínECSS Paris 2023: CP-PN03