Adherence and potential factors of adherence to a resistance, coordination and endurance training in older retirement home residents over 6 months.

INTRODUCTION: High exercise adherence is a key factor for effective exercise programmes. However, little is known about predictors of exercise adherence to a multimodal machine-based training in older retirement home residents. AIMS: To assess exercise adherence and potential predictors of adherence. Furthermore, to evaluate user acceptance of the multimodal training and the change in exercise self-efficacy. METHODS: In this sub-analysis of the bestform-F study, a total of 77 retirement home residents ≥65 years (mean age: 85.6 ± 6.6 years, 77.9% female) participated in a 6-month machine-based resistance, coordination and endurance training. Attendance to the training was documented for each training session. To identify potential predictors a multiple linear regression model was fitted to the data. Analyzed predictors included age, sex, body mass index (BMI), physical function, exercise self-efficacy, and physical activity history. Different domains of user acceptance (e.g. safety aspects, infrastructure) and exercise self-efficacy were assessed by a questionnaire and the exercise self-efficacy scale (ESES), respectively. RESULTS: Mean exercise adherence was 67.2% (median: 74.4%). The regression model (R2 = 0.225, p = 0.033) revealed that the 6-minute walk test (6-MWT) at baseline significantly predicted exercise adherence (ß: 0.074, 95% confidence interval (CI): 0.006-0.142, p = 0.033). Different user domains were rated at least as good by 83.9%-96.9% of participants, reflecting high acceptance. No statistically significant change was found for exercise self-efficacy over 6 months (mean change: 0.47 ± 3.08 points, p = 0.156). CONCLUSION: Retirement home residents attended more than two thirds of offered training sessions and physical function at baseline was the key factor for predicting adherence. User acceptance of the training devices was highly rated. These findings indicate good potential for implementation of the exercise programme.

The Relationship between General Upper-Body Strength and Pole Force Measurements, and Their Predictive Power Regarding Double Poling Sprint Performance.

In recent years, there is an increasing importance of double poling (DP) performance regarding the outcome in classic cross-country skiing (XCS) races. So far, different approaches were used to predict DP performance but there is a lack of knowledge how general strength parameters are related to DP performance parameters gathered from in field-test situations. Therefore, the aim of this study was to determine the relationship between general strength measurements of different upper-body segments and pole force measurements during a DP sprint exercise. In addition, multiple linear regressions were calculated to determine the predictive power of theses variables regarding DP sprint performance, represented as maximum velocity. Thirteen none-elite cross-country skiers performed two 60 m DP sprints at maximal speed on a tartan track using roller skis. In addition, maximum isometric and concentric strength tests were performed on a motor-driven dynamometer with four major upper-body segments (trunk flexion / extension, shoulder / elbow extension). Especially the mean pole force and the strength test parameters correlated significantly (r ≥ 0.615) in all except one comparison. However, regression analyses revealed that neither pole force parameters (R² = 0.495) nor isometric (R² = 0.456) or dynamic (R² = 0.596) strength test parameters could predict the DP performance significantly. This study showed that standardized isokinetic strength tests could be used to estimate pole force capabilities of XCS athletes. However, pole-force and strength test parameters failed to predict significantly maximal velocity during a DP sprint exercise, which might be attributed to the non-elite subject group.

Bestform-F - Best Function of Range of Motion: A Feasibility Study of a Multimodal Exercise Training Program for Older Adults in Retirement Homes.

Purpose: Mobility is a crucial factor for independence and quality of life in old age. Nevertheless, many old people in retirement homes do not meet the physical activity recommendations. The aim of the Bestform-F - Best Function of Range of Motion feasibility study (bestform-F) was to evaluate the feasibility of implementing a machine-based multimodal exercise training program in older residents in retirement homes. Materials and Methods: The participants (n = 77) were recruited from two retirement homes and took part in a six-month multimodal exercise training program (2x/week, 45 minutes) on pneumatic strength training machines, a balance platform and bicycle ergometers. Feasibility criteria were recruitment number ≥ 35 participants within six months, dropout rate < 40% of participants within six months of exercise, and training adherence ≥ 50% of participants taking part in at least 50% of offered training sessions. Additionally, physical performance, fear of falling, cognitive function, and quality of life were assessed at baseline and after six months. Results: For the bestform-F study, 77 (85.6 ± 6.6 years; 78% women) out of 215 eligible residents from two senior residences were recruited. The dropout rate over six months was 10% (8/77 participants). The training adherence rate for the finishing participants was 77% (53/69 participants). In addition to the achieved feasibility criteria, significant improvements were recorded in the Chair Stand Test, Six-Minute Walk Test, and fear of falling after six months. Conclusion: All feasibility criteria have been fulfilled. The high number of recruited participants, the low dropout rate, and high adherence to the training program confirm the feasibility of a multimodal machine-based exercise training program offered to residents in retirement homes. The results provide a basis for a cluster-randomized controlled trial aimed at further investigating the efficacy of the bestform-F program.

Residual force enhancement following shortening is speed-dependent.

The steady-state isometric force following active muscle shortening or lengthening is smaller (force depression; FD) or greater (residual force enhancement; RFE) than a purely isometric contraction at the corresponding length. The mechanisms underlying these phenomena are not explained within the context of the cross-bridge theory and are rarely studied in concert. Previous studies have shown RFE to be speed-independent. In the present study, we investigated if RFE preceded by active shortening is time-dependent by electrically evoking RFE in the human adductor pollicis muscle. The results shown that a slow stretch following FD fully re-established RFE compared to higher speeds of stretch. The mechanism(s) responsible for the recovery of RFE following a preceding shortening contraction (FD) might be associated with the recovery of cross-bridge based force and/or the re-engagement of a passive structural element (titin). Voluntary interaction with one's environment involves highly coordinated shortening and lengthening muscle contractions. Therefore comprehending these history-dependent muscle properties in the context of movement control is paramount in understanding the behavior of in vivo motor control.