Effectiveness of an 11-week exercise intervention for patients with hip or knee osteoarthritis: results of a quasi-experimental pragmatic trial.

OBJECTIVE: To assess the effectiveness of exercise and education in addition to standard care (SC) compared to SC alone in patients with hip or knee osteoarthritis (OA) during 24 months follow-up. DESIGN: We conducted a quasi-experimental pragmatic clinical trial in care centers of a health insurance company. Overall, 1,030 subjects with hip and/or knee OA were included. The intervention group was recruited from clients participating in a hip/knee training (HKT, n = 515) in addition to SC. The control group (CO, n = 515) receiving SC only was recruited from the insurance database. HKT comprised 8 group sessions (1/week) of exercise and education, complemented by a 11-week structured home-exercise program (2/week). Primary endpoints were change of joint-related pain and function (WOMAC Index, score 0-10) after 3 months. Secondary endpoints related to follow-ups at 6, 12 and 24 months. All patient reported outcome measures were analyzed using linear mixed models (LMMs) investigating a time x treatment effect. A multivariable cox proportional hazards regression model was used to identify differences of joint replacement during follow-up between groups. RESULTS: LMMs revealed statistically significant differences in favor of HKT for the primary outcomes WOMAC pain = 0.47 (CI 0.27-0.66; Effect Size (ES) = 0.22, p < 0.001) and WOMAC function = 0.27 (CI 0.11-0.44; ES = 0.13, p < 0.001). HKT was superior to CO for 6, 12, and 24 months as well (ES < 0.2, p ≤ 0.006). HKT was inferior regarding the first incidence of hip or knee AJR during follow-up in comparison to CO (adjusted hazard ratio, HR = 1.57; CI 1.08-2.30; p = 0.020). CONCLUSIONS: This trial demonstrated short-, mid- and long-term superiority of exercise versus control. However, differences were smaller than those reported in previous efficacy trials, raising questions regarding clinical importance. Responder analysis will follow to identify possible predictors for patient responsiveness on an individual level. Further studies should investigate the frequency and reasons for joint replacement following exercise therapy. TRIAL REGISTRATION: German Clinical Trial Register (DRKS00009251). Registered 10 September 2015.

Appraising the Methodological Quality of Sports Injury Video Analysis Studies: The QA-SIVAS Scale.

BACKGROUND: Video analysis (VA) is commonly used in the assessment of sports injuries and has received considerable research interest. Until now, no tool has been available for the assessment of study quality. Therefore, the objective of this study was to develop and evaluate a valid instrument that reliably assesses the methodological quality of VA studies. METHODS: The Quality Appraisal for Sports Injury Video Analysis Studies (QA-SIVAS) scale was developed using a modified Delphi approach including expert consensus and pilot testing. Reliability was examined through intraclass correlation coefficient (ICC3,1) and free-marginal kappa statistics by three independent raters. Construct validity was investigated by comparing QA-SIVAS with expert ratings by using Kendall's tau analysis. Rating time was studied by applying the scale to 21 studies and computing the mean time for rating per study article. RESULTS: The QA-SIVAS scale consists of an 18-item checklist addressing the study design, data source, conduct, report, and discussion of VA studies in sports injury research. Inter- and intra-rater reliability were excellent with ICCs > 0.97. Expert ratings revealed a high construct validity (0.71; p < 0.001). Mean rating time was 10 ± 2 min per article. CONCLUSION: QA-SIVAS is a reliable and valid instrument that can be easily applied to sports injury research. Future studies in the field of VA should adhere to standardized methodological criteria and strict quality guidelines.

Correlates of physical activity enjoyment in children and adolescents for a new perspective on the treatment of overweight: A systematic literature review.

The purpose of this systematic literature review was to systematically compile the state of knowledge on correlates of physical activity enjoyment in children and adolescents to influence the perspective of future physical activity promotion approaches especially for children and adolescents affected by overweight or obesity. The electronic database search was executed in the five databases PubMed, PsychINFO, SPORTDiscus, Web of Science, and BISp-SURF, from inception to December 6, 2021. A semi-quantitative method was used for summarizing the resulted correlates. For final analysis, 85 studies comprising 48,144 children and adolescents were included. Fifty-seven variables could be coded for their relationship with physical activity enjoyment. Of these, 12 psychological variables, for example, the basic psychological needs, task orientation, or self-efficacy; six interpersonal variables, for example, peer/group acceptance, parental support, and autonomy support; and one behavioral variable, the higher self-reported physical activity, are consistent positively associated to physical activity enjoyment. A scientifically based overview could be extracted for the promotion of physical activity enjoyment in children and adolescents. There is a gap in literature focusing the perception of physical activity enjoyment in the subgroup of children and adolescents affected by overweight or obesity. Therefore, recommendations were made to enable the development of further innovative research approaches in this population.

Adipokines as Predictive Biomarkers for Training Adaptation in Subjects with Multimorbidity-A Hypothesis-Generating Study.

BACKGROUND: Physical exercise exerts a positive effect on many chronic conditions, specifically lifestyle-related diseases such as overweight and obesity, type 2 diabetes mellitus (T2DM), cardiovascular conditions and osteoarthritis (OA). As a result of common risk factors, most of these patients present with multiple conditions. Exercise- and disease-related biomarkers, such as adipokines, are emerging tools in training supervision and regulation; however, their significance in subjects with multimorbidities is unknown. SUBJECTS AND METHODS: To address this issue, adipokines leptin, adiponectin and resistin were assessed in a cohort of subjects with multimorbidities (n = 39) presenting with at least two of the abovementioned conditions or relevant risk factors before and after a six-month exercise and lifestyle intervention program ('MultiPill-Exercise'), and correlated with training adaptation, namely changes in relative maximum oxygen uptake (V·O2max). RESULTS: There was a significant negative correlation between baseline leptin concentrations and training effect for relative V·O2max (after three months: rho = -0.54, p = 0.020 *; after six months: rho = -0.45, p = 0.013 *), with baseline leptin explaining 35% of the variance in delta relative V·O2max after three months and 23% after six months. CONCLUSIONS: Leptin might be a suitable surrogate biomarker in the context of exercise-based lifestyle intervention programs in subjects with multimorbidity.

Smartphone-assisted training with education for patients with hip and/or knee osteoarthritis (SmArt-E): study protocol for a multicentre pragmatic randomized controlled trial.

INTRODUCTION: Hip and knee osteoarthritis are associated with functional limitations, pain and restrictions in quality of life and the ability to work. Furthermore, with growing prevalence, osteoarthritis is increasingly causing (in)direct costs. Guidelines recommend exercise therapy and education as primary treatment strategies. Available options for treatment based on physical activity promotion and lifestyle change are often insufficiently provided and used. In addition, the quality of current exercise programmes often does not meet the changing care needs of older people with comorbidities and exercise adherence is a challenge beyond personal physiotherapy. The main objective of this study is to investigate the short- and long-term (cost-)effectiveness of the SmArt-E programme in people with hip and/or knee osteoarthritis in terms of pain and physical functioning compared to usual care. METHODS: This study is designed as a multicentre randomized controlled trial with a target sample size of 330 patients. The intervention is based on the e-Exercise intervention from the Netherlands, consists of a training and education programme and is conducted as a blended care intervention over 12 months. We use an app to support independent training and the development of self-management skills. The primary and secondary hypotheses are that participants in the SmArt-E intervention will have less pain (numerical rating scale) and better physical functioning (Hip Disability and Osteoarthritis Outcome Score, Knee Injury and Osteoarthritis Outcome Score) compared to participants in the usual care group after 12 and 3 months. Other secondary outcomes are based on domains of the Osteoarthritis Research Society International (OARSI). The study will be accompanied by a process evaluation. DISCUSSION: After a positive evaluation, SmArt-E can be offered in usual care, flexibly addressing different care situations. The desired sustainability and the support of the participants' behavioural change are initiated via the app through audio-visual contact with their physiotherapists. Furthermore, the app supports the repetition and consolidation of learned training and educational content. For people with osteoarthritis, the new form of care with proven effectiveness can lead to a reduction in underuse and misuse of care as well as contribute to a reduction in (in)direct costs. TRIAL REGISTRATION: German Clinical Trials Register, DRKS00028477. Registered on August 10, 2022.

Comparison of a Group-/Home-Based and a Weight-Machine-Based Exercise Training for Patients with Hip or Knee Osteoarthritis-A Secondary Analysis of Two Trial Interventions in a Real-World Context.

This study aimed to compare an individual weight-machine-based strengthening program (MbT) with a group-/homebased training offering strengthening/functional exercises (GHT) in a general health care setting. A total of 657 participants (GHT = 521, MbT = 136) suffering from hip/knee OA were included and analysed with a pre-post design (baseline (T0)/3-months (T1)). Primary outcomes were pain and physical functioning (Western Ontario and McMaster Universities Osteoarthritis Index, range 0-10). Additionally, adherence and perceived patient benefit were measured (T1). Data were analysed with linear mixed models (time, treatment, baseline pain/physical impairment severity) adjusted for patient characteristics. No significant between-group differences in pain reduction/functional improvements (time*treatment*baseline pain/physical impairment severity, pain/function: n.s.; time*treatment, pain: p = 0.884, function: p = 0.067). Within-group improvements were dependent on baseline severity: Higher severity levels demonstrated larger changes from baseline. Perceived patient-benefit (very high to high, GHT: 78%, MbT: 92%) and exercise adherence (Dropouts T1: GHT: 27.8%, MbT: 16.2%; adherence to supervised sessions: GHT: 89%, MbT: 92%) was slightly better in the MbT. In summary, both MbT and GHT, showed positive results for patients with at least moderate disease symptoms. Findings for physical functioning, perceived patient-benefit, exercise adherence hint towards a superiority of MbT. Individual preferences should be considered when prescribing exercise therapy. Trial registration: (1) German Clinical Trial Register DRKS00009251. Registered 10 September 2015. (2) German Clinical Trial Register DRKS00009257. Registered 11 September 2015.

Fatigue Prediction in Outdoor Running Conditions using Audio Data.

Although running is a common leisure activity and a core training regiment for several athletes, between 29% and 79% of runners sustain an overuse injury each year. These injuries are linked to excessive fatigue, which alters how someone runs. In this work, we explore the feasibility of modelling the Borg received perception of exertion (RPE) scale (range: [6]-[19] [20]), a well-validated subjective measure of fatigue, using audio data captured in realistic outdoor environments via smartphones attached to the runners' arms. Using convolutional neural networks (CNNs) on log-Mel spectrograms, we obtain a mean absolute error (MAE) of 2.35 in subject-dependent experiments, demonstrating that audio can be effectively used to model fatigue, while being more easily and non-invasively acquired than by signals from other sensors.

Proof of Concept of a 6-Month Person-Oriented Exercise Intervention 'MultiPill-Exercise' among Patients at Risk of or with Multiple Chronic Diseases: Results of a One-Group Pilot Trial.

Physical exercise has been shown to be effective in the treatment of non-communicable chronic diseases. However, patients with multiple chronic diseases (multimorbidity) have received little attention in health policy. This pilot trial served as a proof of concept of a 6-months person-oriented exercise intervention for people at risk of or with diagnosed cardiovascular diseases, diabetes mellitus type 2, overweight and/or hip/knee osteoarthritis, regarding effects on health outcomes as well as adherence and safety. The intervention ('MultiPill-Exercise') was designed to promote physical exercise participation, considering an individual perspective by addressing personal and environmental factors. Outcomes were assessed at baseline (t0) and after three- (t3) and six-months (t6). The primary outcome was self-reported physical exercise participation in minutes/week comparing t3 and t6 vs. t0. Secondary outcomes included cardio-respiratory fitness (maximum oxygen uptake VO2peak during incremental cycling ergometry), isometric peak torque of knee extensors and flexors, health-related quality of life (Veterans Rand 12 with its subscales of perceived general health (GH), mental health (MCS), and physical health (PCS)) and blood levels. Adherence to exercise (% of attended sessions during the first 12-weeks of the intervention) and adverse events were monitored as well. Data were analyzed using a non-parametric procedure for longitudinal data, estimating rank means (MRank) and relative treatment effects (RTE) as well as linear-mixed effect models for parametric data. The primary endpoint of physical exercise participation was significantly higher at t3 and t6 compared to baseline (t3 vs. t0: MRank = 77.1, p < 0.001, RTE: 0.66; t6 vs. t0: MRank = 70.6, p < 0.001, RTE = 0.60). Improvements at both follow-up time points compared to t0 were also found for relative VO2peak (t3 vs. t0 = 2.6 mL/kg/min, p < 0.001; t6 vs. t0 = 2.0 mL/kg/min, p = 0.001), strength of knee extensors (t3 vs. t0 = 11.7 Nm, p = 0.007; t6 vs. t0= 18.1 Nm, p < 0.001) and GH (t3 vs. t0 = 16.2, p = 0.003; t6 vs. t0 = 13.4, p = 0.008). No changes were found for MCS, PCS and for blood levels. Overall exercise adherence was 77%. No serious adverse events were recorded. Results of this pilot trial represent a first proof of concept for the intervention 'MultiPill-Exercise' that will now be implemented and evaluated in a real-world health care setting.

Supporting families to achieve a healthy weight development for their child with overweight/obesity using the STARKIDS intervention: study protocol for a cluster-randomized controlled trial.

BACKGROUND: Childhood and adolescent overweight and obesity are among the most serious health challenges today. Structured weight reduction programs can be helpful to reduce severe health consequences but evidence is partly scarce. The STARKIDS program aims to improve on some of these limitations and is designed to be a structured, stepwise, digitally supported intervention program for the whole family. It is divided into two intervention steps spanning over 1.5 years and aims at promoting a healthy weight development of children/adolescents with overweight/obesity and an increase in quality of life. METHODS: The STARKIDS intervention is evaluated in a cluster-randomized study design by comparing it with a control group receiving a one-time structured counselling in the pediatric practice. The study aims to include 1000 families with children/adolescents with overweight/obesity from 100 pediatric practices. The main outcomes are reduction in body mass index percentiles and improvements in children's/adolescent's quality of life, secondary outcomes refer to the contents of the intervention such as diet, physical activity, stress, and media habits. All outcomes are measured on three measurement time points: (T0) at baseline/inclusion in the study, (T1) baseline + 12 months which is the end of step 1 of the STARKIDS intervention, and (T2) baseline + 18 months which is the end of step 2 of the STARKIDS intervention. DISCUSSION: The stepwise, e-health-supported STARKIDS program is a low-threshold intervention program for families with children/adolescents with overweight/obesity. With the proof of concept, STARKIDS provides the potential to be implemented as a standard care tool for the prevention and intervention of childhood/adolescence obesity in the German health system. TRIAL REGISTRATION: German Clinical Trials Register (DRKS) DRKS00022813  (acknowledged primary register of the World Health Organization). Registered on 27 November 2020 (Universal Trial Number U1111-1254-9536).

Implementation and evaluation of an individualized physical exercise promotion program in people with manifested risk factors for multimorbidity (MultiPill-Exercise): a study protocol for a pragmatic randomized controlled trial.

BACKGROUND: Multimorbidity is a major problem in Europe, increasing the need for prevention and rehabilitation programs. In Germany no guidelines have been developed that focus on patients with multiple chronic non-communicable diseases (NCDs). Benefits of physical activity (PA) and exercise in NCDs have been proven, but most interventions focus on single conditions. The evaluation of the effectiveness, efficiency and safety of PA programs in patients suffering from multiple NCDs and the feasibility of the implementation within the health care service remain open research questions. METHODS: The multi-site randomized controlled pragmatic trial includes 320 sedentary subjects with at least two of the following NCDs, either manifested or in a pre-stage with evident risk factors: Cardio-vascular disease, Diabetes mellitus type 2, knee/ hip osteoarthritis and obesity. Participants will be recruited from general practitioners and medical specialists and randomized to standard care of a statutory health insurance or MultiPill-Exercise. Standard care includes a choice of one or a maximum of two 8- to 12-week health programs, including nutrition, exercise, relaxation or special disease management programs. MultiPill-Exercise is based on the bio-psycho-social health model, considering a person-oriented perspective in light of given individual characteristics and context factors. The 24-weeks intervention focuses on aerobic and strengthening exercises in line with the WHO PA recommendations. Psychological and pedagogical elements along with behavior change techniques are implemented to ease the initiation and maintenance of exercise participation and lifestyle change, including nutrition. Primary outcome will be short- and long-term PA measured with the European Health Interview Survey-Physical Activity Questionnaire (EHIS-PAQ). Secondly, the effectiveness of the program on generic, disease specific, economic, and exercise behavioral parameters, as well as program adherence and safety will be evaluated. DISCUSSION: Results of this trial evaluate the PA intervention program in people with multiple NCDs in a real-life scenario. It will serve as a proof of concept with the opportunity of translation into routine practice. This approach, as a multi-site RCT with its rigorous methods and standardized operating procedures for the conduction of the intervention, will allow valid conclusions for the implementation of PA interventions in people with multimorbidity. TRIAL REGISTRATION: The trial was registered at www.drks.de (ID: DRKS00025033 ) on 30th September 2021.

Effect of Two Different Training Interventions on Cycling Performance in Mountain Bike Cross-Country Olympic Athletes.

To improve performance in endurance sports, it is important to include both high-intensity and low-intensity training, but there is neither a universally accepted practice nor clear scientific evidence that allows reliable statements about the predominance of a specific training method. This randomized controlled trial compared the effects of a polarized training model (POL) to a low-intensity training model (LIT) on physiological parameters and mountain bike cross-country Olympic (XCO) race performance in eighteen competitive XCO athletes (17.9 ± 3.6 years). The superiority of one of the two methods could not be shown in this study. The results did not show statistically significant differences between POL and LIT, as both interventions led to slight improvements. However, a small tendency toward better effects for POL was seen for cycling power output during the race (4.4% vs. -2.2%), at the 4 mmol/L (6.1% vs. 2.8%) and individual anaerobic lactate threshold (5.1% vs. 2.3%), and for maximal aerobic performance (4.4% vs. 2.6%), but not for maximal efforts lasting 10 to 300 s. Despite the lack of significant superiority in this and some other studies, many athletes and coaches prefer POL because it produces at least equivalent effects and requires less training time.

The Relation of Attitude Toward Technology and Mastery Experience After an App-Guided Physical Exercise Intervention: Randomized Crossover Trial.

BACKGROUND: Physical exercise has been found to assert a positive impact on many muscular conditions. Exercise under face-to-face supervision is the gold standard, but access to it is limited, for instance, for economic reasons. App-guided therapy is an intervention that is more affordable and easily accessible. However, attitude toward technology is a key predictor for media adoption and is therefore expected to shape user experience during app-guided therapy. This might be of particular importance for mastery experience, which is crucial for promoting exercise-related self-efficacy and perceived usefulness of the interaction. Both should empower patients to continuously exercise. OBJECTIVE: This study sought to test whether attitudes toward technology predict mastery experience and perceived usefulness of the interaction after an app- versus a physiotherapist-guided treatment. We expect that attitudes toward technology positively predict both outcomes in case of the app-guided but not in case of the physiotherapist-guided treatment. METHODS: Patients (n=54) with clinically diagnosed hip osteoarthritis participated in 2 training sessions with the same exercise intervention, once guided by an app on a tablet computer and once guided by a physiotherapist in a German university hospital. The order of the sessions was randomized. Attitude toward technology was assessed as predictor before the first session, while mastery experience and the global perceived usefulness of interaction as self-reported outcomes after each session. RESULTS: In line with our hypotheses, attitude toward technology predicted mastery experience (b=0.16, standard error=0.07, P=.02) and usefulness of interaction (b=0.17, standard error=0.06, P=.01) after the app-based training but not after the training delivered by a physiotherapist (P>.3 in all cases). Mastery experience was lower for the app-based training but reached a very similar level as the physiotherapist-guided training for those holding a very positive attitude toward technology. CONCLUSIONS: The attitude toward technology predicts the extent of mastery experience after app-guided exercise therapy. As mastery experience is highly important for self-efficacy and future exercise behavior, attitudes toward technology should be considered when delivering app-guided exercise treatments. TRIAL REGISTRATION: German Clinical Trials Register DRKS00015759; https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00015759.

Secondary Analysis of a Study on Exercise Therapy in Hip Osteoarthritis: Follow-Up Data on Pain and Physical Functioning.

We evaluated the short- and longer-term effects of exercise therapy in hip osteoarthritis patients (OA) at baseline, three, six, and 12 months in a randomized setting, followed by a non-randomized setting. The primary randomized intervention (E = exercise, P = placebo-ultrasound, C = control) was followed by a voluntary three-month exercise therapy for P and C (renamed P-E, C-E). Participants randomized to E were not offered treatment again (E-C). Effect sizes (ES; 95% CI) were calculated for within-group effects across time for bodily pain (SF-36) and WOMAC pain, function, and stiffness. ANCOVAs of post-treatment scores were used for group comparison after the group-specific exercise intervention phase. Exercise adherence was assessed and related to post-treatment scores of clinical outcomes. Data of 115 participants of the RCT eligible for follow-up and completing exercise therapy were included into our analyses. Small to medium beneficial long-term effects of cumulative interventional effects, including exercise training, persisted in all groups. Group E-C (n = 49) showed significant 12 months vs. baseline within-group ES in all outcomes (ES 0.39-0.59) except stiffness. Findings were less prominent for exercise therapy in a non-randomized setting (C-E, P-E, both n = 33). Differences are partially explained by adherence rates, highlighting the relevance of therapy compliance strategies. Short-term between-group differences (ANCOVAs) only showed statistically significant differences for WOMAC function between P-E and E-C in favor of E-C (6.4 (95% CI 1.6-11.2; score range 0-100)).

Effectiveness of Human Versus Computer-Based Instructions for Exercise on Physical Activity-Related Health Competence in Patients with Hip Osteoarthritis: Randomized Noninferiority Crossover Trial.

BACKGROUND: Hip and knee osteoarthritis is ranked as the 11th highest contributor to global disability. Exercise is a core treatment in osteoarthritis. The model for physical activity-related health competence describes possibilities to empower patients to perform physical exercises in the best possible health-promoting manner while taking into account their own physical condition. Face-to-face supervision is the gold standard for exercise guidance. OBJECTIVE: The aim of this study was to evaluate whether instruction and guidance via a digital app is not inferior to supervision by a physiotherapist with regard to movement quality, control competence for physical training, and exercise-specific self-efficacy. METHODS: Patients with clinically diagnosed hip osteoarthritis were recruited via print advertisements, emails and flyers. The intervention consisted of two identical training sessions with one exercise for mobility, two for strength, and one for balance. One session was guided by a physiotherapist and the other was guided by a fully automated tablet computer-based app. Both interventions took place at a university hospital. Outcomes were assessor-rated movement quality, and self-reported questionnaires on exercise-specific self-efficacy and control competence for physical training. Participants were randomly assigned to one of two treatment sequences. One sequence started with the app in the first session followed by the physiotherapist in the second session after a minimum washout phase of 27 days (AP group) and the other sequence occurred in the reverse order (PA group). Noninferiority was defined as a between-treatment effect (gIG)<0.2 in favor of the physiotherapist-guided training, including the upper confidence interval. Participants, assessors, and the statistician were neither blinded to the treatment nor to the treatment sequence. RESULTS: A total of 54 participants started the first training session (32 women, 22 men; mean age 62.4, SD 8.2 years). The treatment sequence groups were similar in size (PA: n=26; AP: n=28). Seven subjects did not attend the second training session (PA: n=3; AP: n=4). The app was found to be inferior to the physiotherapist in all outcomes considered, except for movement quality of the mobility exercise (gIG -0.13, 95% CI -0.41-0.16). In contrast to the two strengthening exercises in different positions (supine gIG 0.76, 95% CI 0.39-1.13; table gIG 1.19, 95% CI 0.84-1.55), movement quality of the balance exercise was close to noninferiority (gIG 0.15, 95% CI -0.17-0.48). Exercise-specific self-efficacy showed a strong effect in favor of the physiotherapist (gIG 0.84, 95% CI 0.46-1.22). In terms of control competence for physical training, the app was only slightly inferior to the physiotherapist (gIG 0.18, 95% CI -0.14-0.50). CONCLUSIONS: Despite its inferiority in almost all measures of interest, exercise-specific self-efficacy and control competence for physical training did improve in patients who used the digital app. Movement quality was acceptable for exercises that are easy to conduct and instruct. The digital app opens up possibilities as a supplementary tool to support patients in independent home training for less complex exercises; however, it cannot replace a physiotherapist. TRIAL REGISTRATION: German Clinical Trial Register: DRKS00015759; http://www.drks.de/DRKS00015759.

Physical activity promotion for multimorbid patients in primary care settings: a protocol for a systematic review evaluating health benefits and harms.

BACKGROUND: To date multimorbidity has not received much attention in health policies, even though multiple chronic diseases put high demands on the health care system in industrial nations. Enormous costs of care and a physically, mentally, and socially reduced quality of life are common consequences of multimorbidity. Physical activity (PA) has a positive preventive and therapeutic effect on common non-communicable diseases. The objective of this study will be to evaluate the health benefits and harms of PA interventions for sedentary adults with multimorbidity in primary care settings. METHODS: This is the study protocol for a systematic review. We will search PubMed, MEDLINE (Ovid), Web of Science, CINHAL, and the Cochrane Library (from inception onwards). In addition, clinical trial registers and reference lists of included studies will be searched. We will include randomized controlled trials, quasi-experimental, and non-randomized trials examining the health benefits and harms of PA interventions with or without additional lifestyle interventions for sedentary adult patients with multimorbidity (e.g., two or more chronic non-communicable diseases) in primary care. Eligible control groups will be standard care, placebo, or medications. Two reviewers will independently screen all citations, abstracts data, and full-text articles. The primary outcomes will be health-related quality of life and mortality. Secondary outcomes will include cardiovascular fitness, muscular strength and disease-specific outcomes (e.g., depression score), biomarkers as well as control of metabolic risk factors (e.g., blood pressure, HBA1c, body weight) and any adverse event. The methodological quality of the studies will be appraised using appropriate tools. If feasible, we will conduct random effects meta-analysis. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g., study design, geographical location, or type of intervention). Strength of the body of evidence will be assessed according to the Grading of Recommendations Assessment (GRADE). DISCUSSION: This review will evaluate the evidence on health benefits and harms of PA interventions for sedentary adults with multimorbidity in primary care settings. We anticipate our findings to be of interest to patients, their families, caregivers, and healthcare professionals in selecting and conducting optimal health promotion programs. Possible implications for further research will be discussed. SYSTEMATIC REVIEW REGISTRATION: Open Science Framework (registration identifier: osf.io/ka8yu).

Cycling Performance in Short-term Efforts: Laboratory and Field-Based Data in XCO Athletes.

Mountain bike cross-country Olympic has an intermittent performance profile, underlining the importance of short-term but high cycling power output. Previous findings indicate that power output during sprint tests differs between laboratory and field-based conditions and that cycling cadence rises with increasing workload. The aim was therefore to examine power output and cadence in short-term efforts under laboratory and field conditions. Twenty-three competitive athletes (17.9±3.7 years) performed a laboratory power profile test and a simulated race within one week. Power output and cadence during the power profile test were compared to corresponding short-term efforts during the race over durations of 10-300s (TT 10-300 ). Differences were TT 10 +8%, TT 30 +7%, TT 60 -15% and TT 300 -12% for power output and+10%,+8%,+19%,+21% for cadence respectively. Compared to the race, we found higher power output during the power profile test for the shorter efforts but lower for TT 60 and TT 300 . Confirming previous results, cadence was higher during the power profile test compared to the respective intervals of the race and increased with increasing workload or shorter time trial duration. Future research should take into account that compared to the field, a higher cadence is used in laboratory settings to produce similar power output.

A 12-week exercise program for patients with hip osteoarthritis has no influence on gait parameters: A secondary analysis of a randomized controlled trial.

BACKGROUND: Hip osteoarthritis is a major musculoskeletal disorder in the elderly. Evidence is given for the efficacy of exercise interventions in terms of self-reported physical functioning and pain. However, it has not yet been fully examined whether exercises influence gait. RESEARCH QUESTION: The purpose of this RCT therefore was to evaluate effects of a 12-week exercise program on kinematic gait variables in subjects with hip osteoarthritis. METHODS: 210 participants were randomly assigned to exercise, non-treated control, or placebo ultrasound groups. The 12-week exercise intervention combined a weekly group session with home-based exercises (2/week), which entailed exercises for motor learning, flexibility, strengthening, and balance. Placebo ultrasound was given once a week. A 6-camera motion capture system was used for data collection. Data were derived from shod walking at self-selected speeds. Spatio-temporal and hip and knee joint angles of the stance phase were calculated. Data were averaged across five trials. Measurements were taken prior to and immediately after the intervention period. ANOVA/Kruskall-Wallis-Tests were used to analyze between-group effects for differences between test days. Pairwise comparisons were subsequently conducted in case of significant model effects. Data were analyzed per protocol (n = 185). RESULTS: No statistically significant differences were detected for any of the outcome measures. SIGNIFICANCE: Although hip muscle strength and gait quality are related, strength training of the hip-surrounding musculature without specific gait training elements cannot improve spatio-temporal gait characteristics or hip and knee joint angles in subjects with mild to moderate hip osteoarthritis. If gait should explicitly be improved through exercise, interventions must incorporate a relevant portion of gait-related tasks.

Predictive Ability of a Laboratory Performance Test in Mountain Bike Cross-country Olympic Athletes.

Mountain bike Cross-Country Olympic (XCO) has an intermittent performance profile, underlining the importance of anaerobic metabolism. Traditional performance tests in cycling primarily quantify aerobic metabolism and inadequately meet the demands in XCO. The aim was therefore to validate a specific test that quantifies these requirements by means of an XCO race.Twenty-three competitive XCO athletes (17.9±3.6 years) performed a previously developed performance test and an XCO race within one week. Correlations between individual anaerobic threshold (IAT), 4 mmol lactate threshold (LT4), maximal aerobic power (MAP), maximal effort time trials (TT) for 10-300 s and mean power output of the race (POR) were calculated. In addition, a multiple regression model of the predictive value of the test was calculated.Variables correlated significantly (p<.01) with POR: IAT (r=.81), LT4 (r=0.79), MAP (r=0.91), TT10 (r=0.75), TT30 (r=0.85), TT60 (r=0.84) and TT300 (r=0.86). In the regression model, sex and body mass were set influencing variables (R²adj.=0.70), whereby MAP had the highest correlation with POR and significantly improved the predictive value of the model (R²adj.=0.86).The high correlation of collected performance variables with POR indicated the MTB-PT's additional benefit for performance testing in XCO because it is specific but very feasible.

Predictive ability of a comprehensive incremental test in mountain bike marathon.

OBJECTIVES: Traditional performance tests in mountain bike marathon (XCM) primarily quantify aerobic metabolism and may not describe the relevant capacities in XCM. We aimed to validate a comprehensive test protocol quantifying its intermittent demands. METHODS: Forty-nine athletes (38.8±9.1 years; 38 male; 11 female) performed a laboratory performance test, including an incremental test, to determine individual anaerobic threshold (IAT), peak power output (PPO) and three maximal efforts (10 s all-out sprint, 1 min maximal effort and 5 min maximal effort). Within 2 weeks, the athletes participated in one of three XCM races (n=15, n=9 and n=25). Correlations between test variables and race times were calculated separately. In addition, multiple regression models of the predictive value of laboratory outcomes were calculated for race 3 and across all races (z-transformed data). RESULTS: All variables were correlated with race times 1, 2 and 3: 10 s all-out sprint (r=-0.72; r=-0.59; r=-0.61), 1 min maximal effort (r=-0.85; r=-0.84; r=-0.82), 5 min maximal effort (r=-0.57; r=-0.85; r=-0.76), PPO (r=-0.77; r=-0.73; r=-0.76) and IAT (r=-0.71; r=-0.67; r=-0.68). The best-fitting multiple regression models for race 3 (r2=0.868) and across all races (r2=0.757) comprised 1 min maximal effort, IAT and body weight. CONCLUSION: Aerobic and intermittent variables correlated least strongly with race times. Their use in a multiple regression model confirmed additional explanatory power to predict XCM performance. These findings underline the usefulness of the comprehensive incremental test to predict performance in that sport more precisely.

Subgrouping and TargetEd Exercise pRogrammes for knee and hip OsteoArthritis (STEER OA): a systematic review update and individual participant data meta-analysis protocol.

INTRODUCTION: Knee and hip osteoarthritis (OA) is a leading cause of disability worldwide. Therapeutic exercise is a recommended core treatment for people with knee and hip OA, however, the observed effect sizes for reducing pain and improving physical function are small to moderate. This may be due to insufficient targeting of exercise to subgroups of people who are most likely to respond and/or suboptimal content of exercise programmes. This study aims to identify: (1) subgroups of people with knee and hip OA that do/do not respond to therapeutic exercise and to different types of exercise and (2) mediators of the effect of therapeutic exercise for reducing pain and improving physical function. This will enable optimal targeting and refining the content of future exercise interventions. METHODS AND ANALYSIS: Systematic review and individual participant data meta-analyses. A previous comprehensive systematic review will be updated to identify randomised controlled trials that compare the effects of therapeutic exercise for people with knee and hip OA on pain and physical function to a non-exercise control. Lead authors of eligible trials will be invited to share individual participant data. Trial-level and participant-level characteristics (for baseline variables and outcomes) of included studies will be summarised. Meta-analyses will use a two-stage approach, where effect estimates are obtained for each trial and then synthesised using a random effects model (to account for heterogeneity). All analyses will be on an intention-to-treat principle and all summary meta-analysis estimates will be reported as standardised mean differences with 95% CI. ETHICS AND DISSEMINATION: Research ethical or governance approval is exempt as no new data are being collected and no identifiable participant information will be shared. Findings will be disseminated via national and international conferences, publication in peer-reviewed journals and summaries posted on websites accessed by the public and clinicians. PROSPERO REGISTRATION NUMBER: CRD42017054049.