Drafting in long-track speed skating team pursuit on the ice rink.

Drafting is distinctive for team pursuit races in long-track speed skating. This study aims to compare the impact of drafting on physical intensity (heart rate [HR]) and perceived intensity (ratings of perceived exertion [RPE]) per drafting position. Eighteen skilled male (n = 9) and female (n = 9) skaters (20.0 ± 4.8 years) skated three trials, in first, second or third position, with consistent average velocity (F2,10 = 2.30, p = 0.15, ηp2 = 0.32). Differences in HR and RPE (Borg CR-10 scale) were compared within-subjects (three positions) using a repeated-measures ANOVA (p < 0.05). Compared to the first position, HR was lower in the second (benefit 3.2%) and third (benefit 4.7%) position and lower in third compared to second position (benefit 1.5%), observed in 10 skaters (F2,28 = 28.9, p < 0.001, ηp2= 0.67). RPE was lower when comparing second (benefit 18.5%) and third (benefit 16.8%) position to first (F1.3,22.1 = 7.02, p < 0.05, ηp2= 0.29) and similar for third and second positions., observed in 8 skaters. Even though the physical intensity was lower when drafting in third versus second position, the perceived intensity was equal. There were large interindividual differences between skaters. Coaches are advised to adopt a multidimensional, tailored approach when selecting and training skaters for a team pursuit.

Objectively-assessed physical activity and self-reported activity pacing in adults with multiple sclerosis: A pilot study.

OBJECTIVE: To examine the association between self-reported activity pacing (a strategy to manage fatigue symptoms) and objectively-measured physical activity behaviours in adults with multiple sclerosis. DESIGN: Single cross-sectional study. SETTING: Multiple sclerosis rehabilitation centre in Colchester, United Kingdom. SUBJECTS: Twenty-one adults (59 ± 9 years) with multiple sclerosis. MAIN MEASURES: Physical activity behaviours (activity level: activity counts per minute; activity variability: highest activity counts per minute each day divided by activity counts per minute on that day) were measured with accelerometers. Self-reported activity pacing (Activity Pacing and Risk of Overactivity Questionnaire), fatigue severity (Fatigue Severity Scale) and health-related quality of life (RAND-12-Item Short-Form Health Survey) were measured. Scatter plots were used to explore associations between measures. RESULTS: Activity level was 258 ± 133 counts per minutes, activity variability was 4 ± 1, self-reported activity pacing was 3 ± 1, fatigue severity was 5 ± 2 and health-related quality of life was 43 ± 8. Increased self-reported activity pacing was associated with lower activity levels and less variability in daily activities. CONCLUSION: This investigation suggests that people with multiple sclerosis who have low physical activity levels could be inappropriately using activity pacing as a reactionary response to their multiple sclerosis symptoms.

Meso-pacing in Olympic and World Championship sprints and hurdles: Medallists save their best for the final.

The aim of this novel study was to analyse performance changes across qualifying heats, semi-finals and finals in world-class sprinters and hurdlers. Finalists' finishing positions, times and rankings at the Olympic Games and IAAF World Championships (2012-2019) were obtained. 78% of gold, 67% of silver and 38% of bronze medallists won their qualifying heat and semi-final, and in most events final placings were associated with finishing positions in the qualifying heats (P ≤ 0.006), but not with finishing times. Medallists ran faster in each successive round (P < 0.001), whereas those finishing between 4th-6th did not improve on their semi-final times. Most athletes finishing last and second-last ran the final slower than both their semi-final and qualifying heats. The short hurdles events, with fixed barrier heights and distances, differed from the other races as the medallists were faster than most rivals in the qualifying rounds (P < 0.05), and their race times did not improve from the semi-final to the final. Coaches should note that the world's best athletes were able to conserve energy for the final within a meso-pacing strategy throughout the championships, which was more important in the short hurdles, and requires preparation within their training regimens.

Effect of a 7-week low intensity synchronous handcycling training programme on physical capacity in abled-bodied women.

This study evaluated the effect of a low-intensity norm duration synchronous handcycle wheelchair training in untrained able-bodied women. The training group (n = 9) received 7-weeks of low-intensity upper body training in an instrumented handcycle on a motor-driven treadmill (MDT), 3 × 30 min/week at 30% heart rate reserve. The control group (n = 10) received no training. Incremental handcycle tests on the MDT were used to determine peak values for oxygen uptake (VO2peak), power output (POpeak), heart rate (HRpeak), minute ventilation (VEpeak), and respiratory exchange ratio (RERpeak), submaximal values for heart rate (HR), oxygen uptake (VO2) and gross efficiency (GE) before and after training. Local perceived discomfort and rate of perceived exertion (RPE) were also assessed. Training significantly improved POpeak (+20%), HRpeak (+3%), RERpeak (+5%), submaximal GE (+21%), VO2 (-20%), VE (-33%), HR (-12%) and RPE was low (7.1 ± 0.5) (p < 0.05). No effects were found in VO2peak and VEpeak (p > 0.05). Though VO2peak did not improve, low-intensity norm duration handcycling training improved handcycling POpeak, while RPE was low. Also, GE increased, suggesting a motor control improvement. Handcycle training seems to be an appropriate exercise mode to improve physical capacity, and prevent early fatigue and overuse in untrained individuals.

Test-retest reliability and concurrent validity of the Adapted Short QUestionnaire to ASsess Health-enhancing physical activity (Adapted-SQUASH) in adults with disabilities.

The current study determined the test-retest reliability and concurrent validity of the Adapted Short QUestionnaire to ASsess Health-enhancing physical activity (Adapted-SQUASH) in adults with disabilities. Before filling in the Adapted-SQUASH twice with a recall period of 2 weeks, participants wore the Actiheart activity monitor up to 1 week. For the test-retest reliability (N = 68), Intraclass correlation coefficients (ICCs) were 0.67 (p < 0.001) for the total activity score (min x intensity/week) and 0.76 (p < 0.001) for the total minutes of activity (min/week). For the concurrent validity (N = 58), the Spearman correlation coefficient was 0.40 (p = 0.002) between the total activity score of the first administration of the Adapted-SQUASH and activity energy expenditure from the Actiheart (kcals kg-1 min-1). The ICC was 0.22 (p = 0.027) between the total minutes of activity assessed with the first administration of the Adapted-SQUASH and Actiheart. The Adapted-SQUASH is an acceptable measure to assess self-reported physical activity in large populations of adults with disabilities but is not applicable at the individual level due to wide limits of agreement. Self-reported physical activity assessed with the Adapted-SQUASH does not accurately represent physical activity assessed with the Actiheart in adults with disabilities, as indicated with a systematic bias between both instruments in the Bland-Altman analysis.

Optimising activity pacing to promote a physically active lifestyle in medical settings: A narrative review informed by clinical and sports pacing research.

Regular exercise can improve wellbeing, yet data are scarce on how persons with disabling conditions may benefit from active lifestyles, due to the complexities of exercise prescription in this population. A novel medical concept for exercise prescription called activity pacing is the subject of this review, which identifies the potential for this strategy to optimally integrate existing medical and sports medicine approaches in promoting physical activity in persons with disabling conditions. Activity pacing is a goal-directed behavioural process of empowering people to confidently develop decision-making and planning over how and where to distribute available energy across daily activities. Currently, different conceptual traditions and definitions of pacing exist with important implications for the implementation and subsequent effectiveness of activity pacing. Application of activity pacing has mostly focused on symptom-reduction to improve self-regulatory behaviour, and less on physical activity stimulation for health and wellbeing. Further studies and greater connection between medical and sports science research are needed on how to adapt, tailor and optimise activity pacing to make it successful. The potential of activity pacing to increase physical activity and lessen fatigue could be a powerful tool to help fight the growing incidence of physical inactivity, particularly in persons with disabling conditions.

Head-to-head competition does not affect pacing or performance in 1 km cycling time trials.

Previous research has shown enhanced performance and altered pacing behaviour in the presence of a virtual opponent during middle-distance cycling time trials with a duration of 2 min and longer. The purpose of this study was to determine whether these effects are also present in cycling time trials of shorter duration. Twelve physically active men completed three 1-km time trials. After a familiarisation trial (FAM), participants performed two experimental conditions: one without opponent (NO) and one with a virtual opponent (OP). Repeated-measures ANOVAs were used to assess differences in pacing and performance using power output and duration (p<0.05). No differences in mean finishing times (FAM: 91.5 ± 7.7 s; NO: 91.6 ± 6.4 s; OP: 90.9 ± 4.9 s; p=0.907) or power output (FAM: 382 ± 111 W; NO: 363 ± 80 W; OP: 367 ± 67; p=0.564) were found between experimental conditions. Furthermore, no differences in pacing profiles between experimental conditions were found (p=0.199). Similarly, rate of perceived exertion did not differ between experimental conditions at any moment (p=0.831). In conclusion, unlike events of a more prolonged duration (>2 min), the presence of an opponent did not affect participants' pacing behaviour in short duration 1-km time trials.

Effects of an Upper-Body Training Program Involving Resistance Exercise and High-Intensity Arm Cranking on Peak Handcycling Performance and Wheelchair Propulsion Efficiency in Able-Bodied Men.

Chaikhot, D, Reed, K, Petroongrad, W, Athanasiou, F, van Kooten, D, and Hettinga, FJ. Effects of an upper-body training program involving resistance exercise and high-intensity arm cranking on peak handcycling performance and wheelchair propulsion efficiency in able-bodied men. J Strength Cond Res 34(8): 2267-2275, 2020-The aim of this study was to determine the training effects of an upper-body training program involving resistance exercise and high-intensity arm cranking on peak handcycling performance, propulsion efficiency, and biomechanical characteristics of wheelchair propulsion in able-bodied men. The training group (n = 10) received a 4-week upper-body resistance training (RT), 70% of 1 repetition maximum, 3 sets of 10 repetitions, 8 exercise stations, 2 times per week, combined with high-intensity interval training (HIIT) 2 times per week. High-intensity interval training consisted of arm-crank exercise, 7 intervals of 2 minutes at 80-90% of peak heart rate (HRpeak) with 2-minute active rest at 50-60% of HRpeak. The control group (n = 10) received no training. Both groups performed a preincremental and postincremental handcycling test until volitional exhaustion to evaluate fitness and a 4-minute submaximal wheelchair propulsion test at comfortable speed (CS), 125 and 145% of CS, to evaluate gross mechanical efficiency (GE), fraction of effective force (FEF), percentage of peak oxygen consumption (% V[Combining Dot Above]O2peak), and propulsion characteristics. Repeated-measures analysis of variance was performed (p < 0.05). Training resulted in a 28.2 ± 16.5% increase in peak power output, 13.3 ± 7.5% increase in V[Combining Dot Above]O2peak, 5.6 ± 0.9% increase in HRpeak, and 3.8 ± 1.5% decrease in HRrest. No training effects on FEF, GE, % V[Combining Dot Above]O2peak, and push characteristics were identified. In conclusion, the combined RT and arm-cranking HIIT improved fitness. However, it seems that this training did not result in improvements in propulsion efficiency and push characteristics. Additional wheelchair skill training may be needed to fully benefit from this advantage in daily life propulsion.

Champions are racers, not pacers: an analysis of qualification patterns of Olympic and IAAF World Championship middle distance runners.

The aim of this study was to analyse qualification patterns in middle distance running and identify whether athletes adopt theoretically optimal tactics, or whether the will to win overrides these. The performances of 295 men and 258 women finalists in the Olympic and IAAF World Championship 800 m and 1500 m events from 1999 to 2017 were analysed across all three rounds of competition. Finishing position, time and ranking amongst all competitors were found for each athlete. Position in the final was correlated with finishing position in the heats and semi-finals (all P < 0.001), but not with finishing times in those rounds. Of the 57 champions, 40 won both their heat and semi-final, even though a lower automatic qualification position would have been sufficient, and only 18 achieved a season's best time in the final. The will to win amongst the eventual champions (and other medallists) suggests predominantly ego oriented behaviour that is encouraged by a performance climate, and which did not appear to differ between men and women. Coaches and athletes are recommended to note that championship-specific physiological and psychological factors are important to develop in training and prior competition to improve both short- and long-term championship strategies.

Handcycling: training effects of a specific dose of upper body endurance training in females.

PURPOSE: This study aims to evaluate a handcycling training protocol based on ACSM guidelines in a well-controlled laboratory setting. Training responses of a specific dose of handcycling training were quantified in a homogeneous female subject population to obtain a more in depth understanding of physiological mechanisms underlying adaptations in upper body training. METHODS: 22 female able-bodied participants were randomly divided in a training (T) and control group (C). T received 7-weeks of handcycling training, 3 × 30 min/week at 65 % heart rate reserve (HRR). An incremental handcycling test was used to determine local, exercise-specific adaptations. An incremental cycling test was performed to determine non-exercise-specific central/cardiovascular adaptations. Peak oxygen uptake (peakVO2), heart rate (peakHR) and power output (peakPO) were compared between T and C before and after training. RESULTS: T completed the training sessions at 65 ± 3 % HRR, at increasing power output (59.4 ± 8.2 to 69.5 ± 8.9 W) over the training program. T improved on handcycling peakVO2 (+18.1 %), peakPO (+31.9 %), and peakHR (+4.0 %). No improvements were found in cycling parameters. CONCLUSION: Handcycling training led to local, exercise-specific improvements in upper body parameters. Results could provide input for the design of effective evidence-based training programs specifically aimed at upper body endurance exercise in females.

Evolution of 1500-m Olympic Running Performance.

PURPOSE: This study determined the evolution of performance and pacing for each winner of the men's Olympic 1500-m running track final from 1924 to 2020. METHODS: Data were obtained from publicly available sources. When official splits were unavailable, times from sources such as YouTube were included and interpolated from video records. Final times, lap splits, and position in the peloton were included. The data are presented relative to 0 to 400 m, 400 to 800 m, 800 to 1200 m, and 1200 to 1500 m. Critical speed and D' were calculated using athletes' season's best times. RESULTS: Performance improved ∼25 seconds from 1924 to 2020, with most improvement (∼19 s) occurring in the first 10 finals. However, only 2 performances were world records, and only one runner won the event twice. Pacing evolved from a fast start-slow middle-fast finish pattern (reverse J-shaped) to a slower start with steady acceleration in the second half (J-shaped). The coefficient of variation for lap speeds ranged from 1.4% to 15.3%, consistent with a highly tactical pacing pattern. With few exceptions, the eventual winners were near the front throughout, although rarely in the leading position. There is evidence of a general increase in both critical speed and D' that parallels performance. CONCLUSIONS: An evolution in the pacing pattern occurred across several "eras" in the history of Olympic 1500-m racing, consistent with better trained athletes and improved technology. There has been a consistent tactical approach of following opponents until the latter stages, and athletes should develop tactical flexibility, related to their critical speed and D', in planning prerace strategy.

Supporting athletes during a challenging situation: recommendations from a global insight of COVID-19 home-based training experience.

BACKGROUND: For athletes, overcoming obstacles in challenging situations like pandemic home training is crucial. Strategies and approaches in this context are not well-documented. Our study aims to investigate such a scenario from a performance standpoint, based on a major global crisis: the COVID-19 pandemic and lockdown. METHODS: This cross-sectional study surveyed athletes without disabilities using online questionnaires (35 languages) from May to July 2020. Questions included aspects of alternative routines, training monitoring, recovery, sleep patterns, injury occurrence/prevention based on structured answers, and an open-ended question on lockdown training experiences. RESULTS: Of the 11,762 athletes from 142 countries, 63% were male, including at World-Class, International, National, State and Recreational levels. During lockdown, 25% athletes used innovative or modern ways to maintain or improve fitness e.g., virtual reality and tracking devices (favoring World-Class level, 30%). Many athletes, regardless of gender (43%) watched video competitions to improve/maintain their mental skills and performance [World-Class (47%) and International (51%)]. Contact frequency between athletes and their coaches was mainly at least once a week (36%), more among higher-level (World-Class/International) than lower-level athletes (27 vs. 16%). Higher-level athletes (≥ 54%) monitored training load and were assisted by their coaches (21%). During lockdown, stretching (67%) was considered one of the primary means of recovery, especially for higher-level athletes (> 70%). Compared to pre-lockdown, about two-thirds of athletes reported "normal" or "improved" sleep quality and quantity, suggesting a low sleep quality pre-lockdown. On average, 40% utilized injury prevention exercises (at least) once a week [World-Class (51%) and International (39%)]. Most injury occurrences during lockdown involved the knee (18%), ankle (16%), and back (9%). Four key themes emerged regarding lockdown experiences: remote training adaptation (e.g., shifting training focus), training creativity (e.g., using household items), performance enhancement opportunities (e.g., refocusing neglected aspects), and mental and motivation challenges. CONCLUSIONS: Both male and female athletes, particularly those of higher levels, displayed some adaptalibity during the COVID-19 lockdown, employing innovative approaches and technology for training. Many athletes implemented load monitoring, recovery, and attentive of injury prevention, while optimizing their sleep quality and quantity. Athletes demonstrated their abilities to navigate challenges, and utilized different coping strategies in response to the lockdown's constraints.

Physical strain of handcycling: an evaluation using training guidelines for a healthy lifestyle as defined by the American College of Sports Medicine.

OBJECTIVE: Developments in assistive technology such as handcycling provide attractive possibilities to pursue a healthy lifestyle for patients with spinal cord injury. The objective of the study is to evaluate physical stress and strain of handcycling against training guidelines as defined by the American College of Sports Medicine (ACSM). DESIGN: Seven able-bodied males conducted an incremental peak exercise handcycling test on a treadmill. In addition, two indoor treadmill (1.3 m/second with an inclination of 0.7% and 1.0 m/second with an inclination of 4.8%) and three outdoor over ground exercise bouts were performed (1.7, 3.3, and 5.0 m/second). One individual handcycled a representative 8-km-distance outdoors. OUTCOME MEASURES: Physical stress and strain were described in terms of absolute and relative power output, oxygen uptake (VO2), gross efficiency (GE), and heart rate (HR). Also, local perceived discomfort (LPD) was determined. RESULTS: Relative handcycling exercise intensities varied between 23.3 ± 4.2 (below the ACSM lower limit of 46%VO2peak) and 72.5 ± 15.1%VO2peak (well above the ACSM lower limit), with GE ranging from 6.0 ± 1.5% at the lower to 13.0 ± 2.6% at the higher exercise intensities. Exercise intensities were performed at 49.8 ± 4.2 to 80.1 ± 10.5%HRpeak. LPD scores were low to moderate (<27 ± 7). CONCLUSION: Handcycling is relatively efficient and exercise intensities > 46%VO2peak were elicited. However, exercise load seems to be underestimated using %HRpeak. LPD was not perceived as limiting. Physiological stress and strain in able-bodied individuals appear to be comparable to individuals with a paraplegia. To understand individualize and optimize upper-body training, different training programs must be evaluated.

Differentiated ratings of perceived exertion in upper body exercise.

This study examined whether differentiated ratings of perceived exertion (RPE) (local; RPEL and central; RPEC) and overall RPE (RPEO) were different between exercise modes (upper- versus lower body) and/or changed after upper body training, providing relevant input for upper body exercise prescription/regulation. Eight rowers completed an incremental cycling test (CY), and incremental handcycle (HC) tests before (HCpre) and after three weeks of handcycle training (HCpost). RPEc was higher during CY (17.4±2.4) compared to HCpost (15.9±1.9). However, RPEo was higher during HCpost (9.1±0.6) compared to CY (8.3±1.1). During the HC tests, RPEL was consistently higher than RPEO at the same PO. Training resulted in higher RPEc (HCpre: 14.6±2.6; HCpost: 15.9±1.9) and RPEo (HCpre: 7.9±0.9; HCpost: 9.1±0.6). No differences were found for RPEL between CY and HCpost (8.7±1.1; 9.3±0.4) and after HC training (HCpre: 9.1±1.0; HCpost: 9.3±0.4). At the point of exhaustion, RPEc was higher in CY than during HCpre and HCpost, suggesting RPEC is not causing exercise termination in HC. Furthermore, RPEL is perceived higher than RPEO during all stages of the incremental HC tests compared to CY. This suggests that in contrast to cycling, local factors during arm work are perceived more strongly than central or overall cues of exertion.

Biomechanics of wheelchair turning manoeuvres: novel insights into wheelchair propulsion.

Introduction: Wheelchair turning biomechanics is an under researched area despite its obvious relevance to functional mobility of wheelchair users. Wheelchair turns might be linked to a higher risk of upper limb injuries due to the increased forces and torques potentially associated with asymmetric movement. Our aim was to obtain a better theoretical understanding of wheelchair turning by biomechanically analyzing turns compared to steady-state straightforward propulsion (SSSFP). Methods: Ten able-bodied men received 12-min familiarization and 10 trials (in a random order) of SSSFP and multiple left and right turns around a rectangular course. A Smartwheel was mounted at the right wheel of a standard wheelchair to measure kinetic parameters during SSSFP and of the inner hand during right turns and the outer hand during left turns. A repeated measures ANOVA was used to detect differences across tasks. Results: Two strategies were identified: 3% demonstrated roll turns and 97% spin turns. Spin turns consisted of three phases: approach, turning and depart phase. The turning phase was accomplished by increasing peak force (72.9 ± 25.1 N vs. 43.38 ± 15.9 N in SSSFP) of the inner hand, while maintaining high push frequency of the outer hand (1.09 ± 0.20 push/s vs. 0.95 ± 0.13 push/s in SSSFP). Peak negative force and force impulse during the turning phase were much higher than SSSFP, 15.3 ± 15.7 and 4.5 ± 1.7 times higher, respectively. Conclusion: The spin turn strategy might carry an increased risk of upper limb injuries due to higher braking force and requires particular attention by rehabilitation professionals to preserve upper limb function of long-term wheelchair users.

Music Alters Conscious Distance Monitoring without Changing Pacing and Performance during a Cycling Time Trial.

Athletes use their own perception to monitor distance and regulate their pace during exercise, avoiding premature fatigue before the endpoint. On the other hand, they may also listen to music while training and exercising. Given the potential role of music as a distractor, we verified if music influenced the athletes' ability to monitor the distance covered during a 20-km cycling time trial (TT20km). We hypothesized that music would elongate cyclists' perceived distance due to reduced attentional focus on exercise-derived signals, which would also change their ratings of perceived exertion (RPE). We also expected that the motivational role of music would also be beneficial in pacing and performance. After familiarization sessions, ten recreational cyclists performed an in-laboratory TT20km while either listening to music or not (control). They reported their RPE, associative thoughts to exercise (ATE), and motivation when they each perceived they had completed 2-km. Power output and heart rate (HR) were continuously recorded. Cyclists elongated their distance perception with music, increasing the distance covered for each perceived 2 km (p = 0.003). However, music reduced the error of conscious distance monitoring (p = 0.021), pushing the perceived distance towards the actual distance. Music increased the actual distance-RPE relationship (p = 0.004) and reduced ATE (p < 0.001). However, music affected neither performance assessed as mean power output (p = 0.564) and time (p = 0.524) nor psychophysiological responses such as HR (p = 0.066), RPE (p = 0.069), and motivation (p = 0.515). Cyclists elongated their distance perception during the TT20km and changed the actual distance-RPE relationship, which is likely due to a music-distractive effect. Although there was a reduced error of conscious distance monitoring, music affected neither pacing nor performance.

Be Aware of the Benefits of Drafting in Sports and Take Your Advantage: A Meta-Analysis.

Purpose: In competitive sports, optimizing performance is the key. An interesting venue to explore is to consider drafting as a pacing strategy. The purpose of this study is to identify the magnitude of drafting benefits for biomechanical, physiological, and psychobiological parameters in and between athletes in cycling, kayaking, running, skating, skiing, and swimming. Design: A systematic review and meta-analysis. Methods: Systematic searches were performed in PubMed, Web of Science, and Embase databases. Results: In total, 205 studies were found, from which 22 were relevant (including 232 participants and 548 observations). Methodological quality was high for all the included articles. The meta-analyses for all parameters indicated strong evidence for a benefit of drafting, with moderate effects between leading and drafting athletes found for the heart rate (3.9%), VO2 (8.9%), power output (11.3%), and rating of perceived exertion (10.4%). Large effect sizes were found for blood lactate (24.2%), VE (16.2%), and EMG (56.4%). A moderator analysis showed differences between sports on the effect of drafting with most benefits in cycling. Discussion. Based on the observed effects of drafting in the biomechanical, physiological, and psychobiological parameters, it can be considered as an element of pacing, a strategy to conserve energy and optimize performance. Conclusion: There is strong evidence that drafting benefits athletes, with varying levels of effect for athletes in different sports. Knowledge about the magnitude of benefits can be used to improve training sessions, race strategies, and performance in competition.

Psychosocial factors of physical activity among people with disabilities: Prospective cohort study.

PURPOSE/OBJECTIVE: This study aimed to (a) explore the associations between psychosocial factors and physical activity behavior in people with physical disabilities and/or chronic diseases, both between and within persons over time; and (b) examine whether these associations differ for people initiating and people maintaining physical activity behavior. RESEARCH METHOD/DESIGN: Data of 1,256 adults with physical disabilities and/or chronic diseases enrolled in the prospective cohort study Rehabilitation, Sports, and Active lifestyle (ReSpAct) were analyzed. Self-reported physical activity and four main psychosocial factors (i.e., self-efficacy, attitude, motivation, social support) were measured with questionnaires 3-6 weeks before discharge (T0) and 14 (T1), 33 (T2), and 52 (T3) weeks after discharge from rehabilitation. Hybrid multilevel regression models (corrected for age, sex, education level, diagnosis, counseling support) were used. RESULTS: Multivariable significant between-subject associations were found for self-efficacy (std ß = .094; 95% CI [0.035, 0.153]) and intrinsic motivation (std ß = .114; [0.036, 0.192]). Multivariable significant within-subject associations were found for identified regulation (std ß = -.038; [-0.072, -0.005]) and intrinsic motivation (std ß = .049; [0.016, 0.082]). Effect modification of initiating or maintaining physical activity was found for the between-subject association of attitude (p = .035). No significant associations were found for social support, amotivation, external regulation, and introjected regulation. CONCLUSION/IMPLICATIONS: This study is the first that explored the between- and within-subject associations between psychosocial factors and physical activity over time in a large cohort of adults with physical disabilities and/or chronic diseases. The findings indicate the importance of intrinsic motivation, identified regulation, and self-efficacy in initiating and maintaining physical activity behavior. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Measurement properties of device-based physical activity instruments in ambulatory adults with physical disabilities and/or chronic diseases: a scoping review.

BACKGROUND: People with physical disabilities and/or chronic diseases tend to have an inactive lifestyle. Monitoring physical activity levels is important to provide insight on how much and what types of activities people with physical disabilities and/or chronic diseases engage in. This information can be used as input for interventions to promote a physically active lifestyle. Therefore, valid and reliable physical activity measurement instruments are needed. This scoping review aims 1) to provide a critical mapping of the existing literature and 2) directions for future research on measurement properties of device-based instruments assessing physical activity behavior in ambulant adults with physical disabilities and/or chronic diseases. METHODS: Four databases (MEDLINE, CINAHL, Web of Science, Embase) were systematically searched from 2015 to April 16th 2023 for articles investigating measurement properties of device-based instruments assessing physical activity in ambulatory adults with physical disabilities and/or chronic diseases. For the majority, screening and selection of eligible studies were done in duplicate. Extracted data were publication data, study data, study population, device, studied measurement properties and study outcome. Data were synthesized per device. RESULTS: One hundred three of 21566 Studies were included. 55 Consumer-grade and 23 research-grade devices were studied on measurement properties, using 14 different physical activity outcomes, in 23 different physical disabilities and/or chronic diseases. ActiGraph (n = 28) and Fitbit (n = 39) devices were most frequently studied. Steps (n = 68) was the most common used physical activity outcome. 97 studies determined validity, 11 studies reliability and 6 studies responsiveness. CONCLUSION: This scoping review shows a large variability in research on measurement properties of device-based instruments in ambulatory adults with physical disabilities and/or chronic diseases. The variability highlights a need for standardization of and consensus on research in this field. The review provides directions for future research.

Competition Between Desired Competitive Result, Tolerable Homeostatic Disturbance, and Psychophysiological Interpretation Determines Pacing Strategy.

Scientific interest in pacing goes back >100 years. Contemporary interest, both as a feature of athletic competition and as a window into understanding fatigue, goes back >30 years. Pacing represents the pattern of energy use designed to produce a competitive result while managing fatigue of different origins. Pacing has been studied both against the clock and during head-to-head competition. Several models have been used to explain pacing, including the teleoanticipation model, the central governor model, the anticipatory-feedback-rating of perceived exertion model, the concept of a learned template, the affordance concept, the integrative governor theory, and as an explanation for "falling behind." Early studies, mostly using time-trial exercise, focused on the need to manage homeostatic disturbance. More recent studies, based on head-to-head competition, have focused on an improved understanding of how psychophysiology, beyond the gestalt concept of rating of perceived exertion, can be understood as a mediator of pacing and as an explanation for falling behind. More recent approaches to pacing have focused on the elements of decision making during sport and have expanded the role of psychophysiological responses including sensory-discriminatory, affective-motivational, and cognitive-evaluative dimensions. These approaches have expanded the understanding of variations in pacing, particularly during head-to-head competition.