New Findings What is the central question of this study?Does eccentric exercise leading to prolonged knee‐extensor torque depression also result in a prolonged loss of knee‐extensor torque complexity? What is the main finding and its importance?The recovery of the loss of torque complexity after eccentric exercise took 24 h, whereas after acute muscle fatigue it took 10 min. The depression of torque complexity after eccentric exercise was prolonged. Abstract Neuromuscular fatigue reduces the temporal structure, or complexity, of muscle torque output. Exercise‐induced muscle damage reduces muscle torque output for considerably longer than high‐intensity fatiguing contractions. We hypothesized that muscle‐damaging eccentric exercise would lead to a persistent decrease in torque complexity, whereas fatiguing exercise would not. Ten healthy participants performed five isometric contractions (6 s contraction, 4 s rest) at 50% maximal voluntary contraction (MVC) before, immediately after and 10, 30 and 60 min and 24 h after eccentric (muscle‐damaging) and isometric (fatiguing) exercise. These contractions were also repeated 48 h and 1 week after eccentric exercise. Torque and surface EMG signals were sampled throughout each test. Complexity and fractal scaling were quantified using approximate entropy (ApEn) and the detrended fluctuation analysis α exponent (DFA α). Global, central and peripheral perturbations were quantified using MVCs with femoral nerve stimulation. Complexity decreased after both eccentric [ApEn, mean (SD), from 0.39 (0.10) to 0.20 (0.12), P < 0.001] and isometric exercise [from 0.41 (0.13) to 0.09 (0.04); P < 0.001]. After eccentric exercise, ApEn and DFA α required 24 h to recover to baseline levels, but after isometric exercise they required only 10 min. The MVC torque remained reduced [from 233.6 (74.2) to 187.5 (64.7) N m] 48 h after eccentric exercise, with such changes evident only up to 60 min after isometric exercise [MVC torque, from 246.1 (77.2) to 217.9 (71.8) N m]. The prolonged depression in maximal muscle torque output is therefore accompanied by a prolonged reduction in torque complexity.

Neuromuscular fatigue reduces the complexity of muscle torque output. Exercise-induced muscle damage reduces muscle torque output for considerably longer than high-intensity fatiguing contractions. We therefore hypothesized that muscle damaging eccentric exercise would lead to a persistent decrease in torque complexity, whereas fatiguing exercise would not. Ten healthy participants performed five isometric contractions (6 s contraction, 4 s rest) at 50% maximal voluntary contraction (MVC) before, immediately after, 10, 30 and 60 minutes, and 24 hours after eccentric (muscle damaging) and isometric (fatiguing) exercise. Further measures were taken 48 hours and one week after eccentric exercise. Torque and surface EMG signals were sampled continuously. Complexity and fractal scaling were quantified using approximate entropy (ApEn) and detrended fluctuation analysis (DFA). Global, central and peripheral perturbations were quantified using MVCs with femoral nerve stimulation. Complexity decreased following both eccentric (ApEn, mean (SD), from 0.39 (0.10) to 0.20 (0.12), P &lt; 0.001) and isometric exercise (from 0.41 (0.13) to 0.09 (0.04); P &lt; 0.001). After eccentric exercise ApEn and DFA α required 24 hours to recover to baseline levels, compared to only 10 minutes following isometric exercise. MVC torque remained reduced (from 233.6 (74.2) N.m to 187.5 (64.7) N.m) and submaximal EMG amplitude increased (from 51.2 (6.9)% to 68.4 (11.3)%) 48 hours after eccentric exercise, with such changes only evident up to 60 minutes following isometric exercise (MVC torque, from 246.1 (77.2) to 217.9 (71.8) N.m; submaximal EMG from 52.9 (6.4)% to 66.2 (9.0)%). The prolonged depression in maximal muscle torque output is therefore accompanied by a reduction in torque complexity, suggesting that eccentric exercise diminishes motor control as well as muscle force-generating capacity.

Introduction Approximately 65% of elderly patients admitted to hospital experience some level of deconditioning during their stay. This can lead to longer length of stays, premature admissions to care homes and loss of function whilst in hospital (British Geriatrics Society). There is evidence that exercise can be safe and effective in reversing functional decline in this population. However, there is limited evidence into the effectiveness and feasibility of running a multi modal exercise intervention (eg. Dance and Exercise) on a busy elderly care ward in the UK. Method An 8-week inpatient programme consisting of a 60-minute exercise classes once a week and/or 60-minute dance class once a week started on the Older Person’s Wards at the Royal London. Primary outcome measures included: 5 x Sit To Stands (5xSTS) and Falls Efficacy Scale International (FES-I). Secondary measures; Rockwood score, Barthel Index, Elderly Mobility Score (EMS), Mood, 4AT and handgrip strength. Patient satisfaction scores were also recorded. Results 23 patients were included in the analysis, 3 patients attended the dance class, 14 attended the exercise class and 5 attended both. In total 37 sessions were completed. The average score for all outcome measures improved except one after 8 weeks. The 5xSTS times improved by an average of 7.7 seconds and the FES-I score dropped by 3.9. The Barthel score increased by 5 points. Handgrip strength increased by 2.3 kg and 57% improved on their EMS. Mood improved from 5.4/10 to 6.0/10 and 4AT from 2.7 to 1.7. Overall, 70% of participants reported enjoying the classes and 90% said they would re-attend. Conclusion A multifactorial intervention including seated dance and exercise sessions showed significant improvements in mobility, fear of falling, cognition and functional tasks. Further work will look into the impact on length of stay and readmissions inpatient to hospital.

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