Relationships between sport and exercise participation and subjective well-being among adults with physical disabilities: Is participation quality more important than participation quantity?

Sport and exercise participation are associated with small, albeit positive changes in subjective well-being (SWB). Recent theorizing has emphasized the importance of distinguishing between performance aspects (i.e., frequency, intensity, time engaged) and the experiential aspects of sport and exercise participation among people with disabilities. This study assessed the relative contributions of time spent participating in sport and exercise (a performance measure) versus measures of participation experiences, in explaining variance in SWB. Participants were 535 adults with physical disabilities, recruited through a nation-wide survey, who participated in sport (n = 271; 62% male; 44 ± 14 years) or exercise (n = 264; 42% male; 57 ± 14 years). They completed measures of minutes/week of sport or exercise participation, experiential aspects of participation, and SWB (overall life satisfaction, satisfaction with physical, psychological and social life-domains, and positive/negative affect). Hierarchical multiple regression analyses showed minutes/week of sport did not explain significant variance in any SWB measure, but sport participation experiences explained significant variance (9.2%-20.9%) in all SWB measures (p < 0.05). Similarly, minutes/week of exercise explained significant variance only in physical life-domain satisfaction (ΔR2 = 2.6%, p = 0.026), but exercise participation experiences explained significant variance (4.8%-10.7%) in all SWB measures (p < 0.05). Experiences of belonging and mastery were particularly strong, consistent predictors across SWB outcomes. These results suggest participation experiences better explain relationships between sport and exercise participation and SWB than time spent performing sport and exercise. Findings have implications for designing future studies to test the effects of sport and exercise on SWB, and developing theories and interventions to explain and maximize the use of sport and exercise to improve SWB in adults with disabilities.

Significance of spinal cord perfusion pressure following spinal cord injury: A systematic scoping review.

This scoping review systematically reviewed relevant research to summarize the literature addressing the significance of monitoring spinal cord perfusion pressure (SCPP) in acute traumatic spinal cord injury (SCI). The objectives of the review were to (1) examine the nature of research in the field of SCPP monitoring in SCI, (2) summarize the key research findings in the field, and (3) identify research gaps in the existing literature and future research priorities. Primary literature searches were conducted using databases (Medline and Embase) and expanded searches were conducted by reviewing the references of eligible articles and searches of Scopus, Web of Science core collection, Google Scholar, and conference abstracts. Relevant data were extracted from the studies and synthesis of findings was guided by the identification of patterns across studies to identify key themes and research gaps within the literature. Following primary and expanded searches, a total of 883 articles were screened. Seventy-three articles met the review inclusion criteria, including 34 original research articles. Other articles were categorized as conference abstracts, literature reviews, systematic reviews, letters to the editor, perspective articles, and editorials. Key themes relevant to the research question that emerged from the review included the relationship between SCPP and neurological recovery, the safety of monitoring pressures within the intrathecal space, and methods of intervention to enhance SCPP in the setting of acute traumatic SCI. Original research that aims to enhance SCPP by targeting increases in mean arterial pressure or reducing pressure in the intrathecal space is reviewed. Further discussion regarding where pressure within the intrathecal space should be measured is provided. Finally, we highlight research gaps in the literature such as determining the feasibility of invasive monitoring at smaller centers, the need for a better understanding of cerebrospinal fluid physiology following SCI, and novel pharmacological interventions to enhance SCPP in the setting of acute traumatic SCI. Ultimately, despite a growing body of literature on the significance of SCPP monitoring following SCI, there are still a number of important knowledge gaps that will require further investigation.

Influence of respiratory loading on left-ventricular function in cervical spinal cord injury.

Cervical spinal cord injury (C-SCI) negatively impacts cardiac and respiratory function. As the heart and lungs are linked via the pulmonary circuit these systems are interdependent. Here, we utilized inspiratory and expiratory loading to assess whether augmenting the respiratory pump improves left-ventricular (LV) filling and output in individuals with motor-complete C-SCI. We hypothesized LV end-diastolic volume (LVEDV) would increase and decrease with inspiratory and expiratory loading, respectively. Participants (C-SCI: 7M/1F, 35 ± 7 years; able-bodied: 7M/1F, 32 ± 6 years) were assessed under five conditions during 45° head-up tilt; unloaded, inspiratory loading with -10 and -20 cmH2 O oesophageal pressure (Poes ) on inspiration, and expiratory loading with +10 and +20 cmH2 O Poes on expiration. An oesophageal balloon catheter monitored Poes , and LV structure and function were assessed by echocardiography. In C-SCI only, (1) +20 cmH2 O reduced LVEDV vs. unloaded (81 ± 15 vs. 88 ± 11 ml, P = 0.006); (2) heart rate was higher during +20 cmH2 O compared to unloaded (P = 0.001) and +10 cmH2 O (P = 0.002); (3) cardiac output was higher during +20 cmH2 O than unloaded (P = 0.002); and (4) end-expiratory lung volume was higher during +20 cmH2 O vs. unloaded (63 ± 10 vs. 55 ± 13% total lung capacity, P = 0.003) but was unaffected by inspiratory loading. In both groups, -10 and -20 cmH2 O had no significant effect on LVEDV. These findings suggest greater expiratory positive pressure acutely impairs LV filling in C-SCI, potentially via impaired venous return, mediastinal constraint and/or direct ventricular interaction subsequent to dynamic hyperinflation. Inspiratory loading did not significantly improve LV function in C-SCI and neither inspiratory nor expiratory loading affected cardiac function or lung volumes in able-bodied participants. KEY POINTS: Cervical spinal cord injury (C-SCI) alters both the cardiac and the respiratory system, but little is known about how these systems interact following injury. Here, we manipulated inspiratory or expiratory intrathoracic pressure (ITP) to mechanistically test the role of the respiratory pump in circulatory function in highly trained individuals with C-SCI and an able-bodied reference group. In individuals with C-SCI, greater ITP during expiratory loading caused dynamic hyperinflation that was associated with impaired left-ventricular filling. More negative ITP during inspiratory loading did not significantly alter left-ventricular volumes in either group. Interventions that prevent dynamic hyperinflation and/or enhance the ability to generate expiratory pressures may help preserve left-ventricular filling in individuals with C-SCI.

All over the MAP: describing pressure variability in acute spinal cord injury.

STUDY DESIGN: Observational study. OBJECTIVES: To examine the feasibility of meeting the current clinical guidelines for the hemodynamic management of acute spinal cord injury (SCI) which recommend maintaining mean arterial pressure (MAP) at 85-90 mmHg in the days following injury. METHODS: This study examined data collected minute-by-minute to describe the pressure profile in the first 5 days following SCI in 16 patients admitted to the Intensive Care Unit at Vancouver General Hospital (40 ± 19 years, 13 M/3 F, C4-T11). MAP and intrathecal pressure (ITP) were monitored at 100 Hz by arterial and lumbar intrathecal catheters, respectively, and reported as the average of each minute. Spinal cord perfusion pressure was calculated as the difference between MAP and ITP. The minute-to-minute difference (MMdiff) of each pressure variable was calculated as the absolute difference between consecutive minutes. RESULTS: Only 24 ± 7% of MAP recordings were between 85 and 90 mmHg. Average MAP MMdiff was ~3 mmHg. The percentage of MAP recordings within target range was negatively correlated with the degree of variability (i.e. MMdiff; r = -0.64, p < 0.008) whereas higher mean MAP was correlated with greater variability (r = 0.57, p = 0.021). CONCLUSIONS: Our findings point to the 'real life' challenges in maintaining MAP in acute SCI patients. Given MAP fluctuated ~3 mmHg minute-to-minute, maintaining MAP within a 5 mmHg range with conventional volume replacement and vasopressors presents an almost impossible task for clinicians and warrants reconsideration of current management guidelines.

The effects of active upper-limb versus passive lower-limb exercise on quality of life among individuals with motor-complete spinal cord injury.

STUDY DESIGN: Multi-centre randomized clinical trial. OBJECTIVES: (1) compare the effects of arm-cycle ergometry (ACET) and body weight supported treadmill training (BWSTT) on quality of life (QOL) and intermediary variables in individuals with spinal cord injury (SCI); (2) examine correlations between baseline measures, and changes in physical activity, QOL, and intermediaries. SETTING: Hospital-based research institutes (Vancouver, Toronto) and University-based exercise program (Hamilton). METHODS: 35 participants with motor-complete SCI above T6 completed baseline assessments of physical activity, life satisfaction, independence, autonomy, positive and negative affect, and pain. Twenty-eight participants were randomized to 72 sessions of ACET (n = 14) or BWSTT (n = 14) with measures repeated following 36 sessions, 72 sessions, and 6-months post-intervention. RESULTS: Neither intervention significantly impacted QOL. Pain was reduced in ACET compared to BWSTT (interaction effect p = 0.022) and was significantly less at 72 sessions vs. baseline in the ACET group (p = 0.009). At baseline, QOL was positively correlated with independence, autonomy, and positive affect and negatively correlated with negative affect (all p < 0.05). Following BWSTT, changes in moderate-vigorous physical activity correlated with changes in QOL (r = 0.87, p = 0.010). Following ACET, changes in autonomy and independence were positively correlated with changes in QOL (both r > 0.64, p < 0.048). CONCLUSIONS: Contrary to previous studies, there was no benefit of either intervention on measures of QOL. The social context of exercise may be important for improving QOL. However, individuals may benefit more from active (ACET) than passive (BWSTT) exercise modalities through reduced pain. Exercise interventions that improve autonomy and independence may lead to improvements in QOL.

Is Sleep Disordered Breathing Confounding Rehabilitation Outcomes in Spinal Cord Injury Research?

The purpose of this article is to highlight the importance of considering sleep-disordered breathing (SDB) as a potential confounder to rehabilitation research interventions in spinal cord injury (SCI). SDB is highly prevalent in SCI, with increased prevalence in individuals with higher and more severe lesions, and the criterion standard treatment with continuous positive airway pressure remains problematic. Despite its high prevalence, SDB is often untested and untreated in individuals with SCI. In individuals without SCI, SDB is known to negatively affect physical function and many of the physiological systems that negatively affect physical rehabilitation in SCI. Thus, owing to the high prevalence, under testing, low treatment adherence, and known negative effect on the physical function, it is contended that underdiagnosed SDB in SCI may be confounding physical rehabilitation research studies in individuals with SCI. Studies investigating the effect of treating SDB and its effect on physical rehabilitation in SCI were unable to be located. Thus, studies investigating the likely integrated relationship among physical rehabilitation, SDB, and proper treatment of SDB in SCI are needed. Owing to rapid growth in both sleep medicine and physical rehabilitation intervention research in SCI, the authors contend it is the appropriate time to begin the conversations and collaborations between these fields. We discuss a general overview of SDB and physical training modalities, as well as how SDB could be affecting these studies.

Cardiovascular responses to heat acclimatisation in athletes with spinal cord injury.

OBJECTIVES: To determine the effect of heat acclimatisation (HA) training on blood profile and resting cardiac function in elite athletes with spinal cord injury (SCI). DESIGN: Quasi-experimental. METHODS: Eleven athletes (10m, 1f) with SCI (C5-T3) completed a five-day isothermic HA protocol whereby gastrointestinal temperature (Tc) was elevated to and maintained at ∼38.5 degrees Celsius (°C) via intermittent exercise for sixty minutes each day. Blood samples were collected pre- and post-HA to determine changes in plasma volume (PV). Doppler ultrasound of the left-ventricular outflow tract and 2-d speckle tracking echocardiography were performed in a subset of athletes (n=5) to determine changes in indices of resting left-ventricular function and mechanics, respectively. RESULTS: Ten athletes were successfully able to raise and maintain Tc to 38.5°C. There was a non-significant increase in PV with HA training (ΔPV%: 3.0±5.4%, p=0.086). Following HA, resting HR decreased (63±4 pre-HA vs. 58±5 bpm post-HA, p=0.020), velocity time integral (21.4±2.7 vs. 23.7±3.0cm, p=0.045) and stroke volume increased (64.8±7.6 vs. 70.2±10.5mL, p=0.055). CONCLUSIONS: Our findings suggest a short-term HA protocol in athletes with SCI is safe and may induce beneficial changes in indices of resting left-ventricular function - however results are highly individualized. Future studies on HA in athletes with SCI should focus on determining mechanisms of adaptation and performance outcomes.

Physiological Considerations to Support Podium Performance in Para-Athletes.

The twenty-first century has seen an increase in para-sport participation and the number of research publications on para-sport and the para-athlete. Unfortunately, the majority of publications are case reports/case series or study single impairment types in isolation. Indeed, an overview of how each International Paralympic Committee classifiable impairment type impact athlete physiology, health, and performance has not been forthcoming in the literature. This can make it challenging for practitioners to appropriately support para-athletes and implement evidence-based research in their daily practice. Moreover, the lack of a cohesive publication that reviews all classifiable impairment types through a physiological lens can make it challenging for researchers new to the field to gain an understanding of unique physiological challenges facing para-athletes and to appreciate the nuances of how various impairment types differentially impact para-athlete physiology. As such, the purpose of this review is to (1) summarize how International Paralympic Committee classifiable impairments alter the normal physiological responses to exercise; (2) provide an overview of "quick win" physiological interventions targeted toward specific para-athlete populations; (3) discuss unique practical considerations for the para-sport practitioner; (4) discuss research gaps and highlight areas for future research and innovation, and (5) provide suggestions for knowledge translation and knowledge sharing strategies to advance the field of para-sport research and its application by para-sport practitioners.

Spinal Cord Injury Impairs Cardiovascular Capacity in Elite Wheelchair Rugby Athletes.

OBJECTIVE: To examine differences in heart rate (HR) responses during international wheelchair rugby competition between athletes with and without a cervical spinal cord injury (SCI) and across standardized sport classifications. DESIGN: Observational study. SETTING: The 2015 Parapan American Games wheelchair rugby competition. PARTICIPANTS: Forty-three male athletes (31 ± 8 years) with a cervical SCI (n = 32) or tetraequivalent impairment (non-SCI, n = 11). MAIN OUTCOME MEASURES: Average and peak HR (HRavg and HRpeak, respectively). To characterize HR responses in accordance with an athletes' International Wheelchair Rugby Federation (IWRF) classification, we separated athletes into 3 groups: group I (IWRF classification 0.5-1.5, n = 15); group II (IWRF classification 2.0, n = 15); and group III (IWRF classification 2.5-3.5, n = 13). RESULTS: Athletes with SCI had lower HRavg (111 ± 14 bpm vs 155 ± 13 bpm) and HRpeak (133 ± 12 bpm vs 178 ± 13 bpm) compared with non-SCI (both P < 0.001). Average HR was higher in group III than in I (136 ± 25 bpm vs 115 ± 20 bpm, P = 0.045); however, SCI athletes showed no difference in HRavg or HRpeak between groups. Within group III, SCI athletes had lower HRavg (115 ± 6 bpm vs 160 ± 8 bpm) and HRpeak (135 ± 11 bpm vs 183 ± 11 bpm) than non-SCI athletes (both P < 0.001). CONCLUSIONS: This study is the first to demonstrate attenuated HR responses during competition in SCI compared with non-SCI athletes, likely due to injury to spinal autonomic pathways. Among athletes with SCI, IWRF classification was not related to differences in HR. Specific assessment of autonomic function after SCI may be able to predict HR during competition and consideration of autonomic impairments may improve the classification process.

Respiratory muscle training in athletes with cervical spinal cord injury: effects on cardiopulmonary function and exercise capacity.

KEY POINTS: The effect of combined inspiratory and expiratory muscle training on resting and reflexive cardiac function, as well as exercise capacity, in individuals with cervical spinal cord injury (SCI) is presently unknown. Six weeks of combined inspiratory and expiratory muscle training enhances both inspiratory and expiratory muscle strength in highly-trained athletes with cervical SCI with no significant effect on lung function. There was a significant decrease in left-ventricular filling and stroke volume at rest in response to 45° head-up tilt, which is irreversible by respiratory muscle training. Combined inspiratory and expiratory muscle training increased peak aerobic work rate and reduced end-expiratory lung volumes during exercise, which may have implications for left-ventricular filling during exercise. ABSTRACT: To investigate the pulmonary, cardiovascular and exercise responses to combined inspiratory and expiratory respiratory muscle training (RMT) in athletes with tetraplegia, six wheelchair rugby athletes (five males and one female, aged 33 ± 5 years) completed 6 weeks of pressure threshold RMT, 2 sessions day-1 on 5 days week-1 . Resting pulmonary and cardiac function, exercise capacity, exercising lung volumes and field-based exercise performance were assessed at pre-RMT, post-RMT and after a 6-week no RMT period. RMT enhanced maximal inspiratory (pre- vs. post-RMT: -76 ± 15 to -106 ± 23 cmH2 O, P = 0.002) and expiratory (59 ± 26 to 73 ± 32 cmH2 O, P = 0.007) mouth pressures, as well as peak expiratory flow (6.74 ± 1.51 vs. 7.32 ± 1.60 L/s, P < 0.04). Compared to pre-RMT, peak work rate was higher at post-RMT (60 ± 23 to 68 ± 22 W, P = 0.003), whereas exercising end-expiratory lung volumes were reduced (P < 0.017). Peak oxygen uptake increased in all athletes at post-RMT (1.24 ± 0.40 vs. 1.40 ± 0.50 l min-1 , P = 0.12). After 6 weeks of no RMT all indices returned towards baseline, with peak work rate (P = 0.037), peak oxygen uptake (P = 0.041) and end-expiratory lung volume (P < 0.034) being significantly lower at follow-up than at post-RMT. There was a significant decrease in left-ventricular end-diastolic volume and stroke volume in response to 45° head-up tilt (P = 0.030 and 0.021, respectively); however, all cardiac indices in both supine and tilted positions were unchanged by RMT. Our findings demonstrate the efficacy of RMT with respect to enhancing respiratory muscle strength, lowering exercising lung volumes and increasing exercise capacity. Although the precise mechanisms by which RMT may enhance exercise capacity remain unclear, our data suggest that it is probably not the result of a direct cardiac adaptation associated with RMT.

Effect of Unintentional Boosting on Exercise Performance in a Tetraplegic Athlete.

Boosting is the induction of autonomic dysreflexia (AD) to reflexively activate otherwise dormant thoracolumbar sympathetic circuitry to "boost" the capacity of the cardiovascular system and enhance exercise performance. AD is a life-threatening condition unique to individuals with spinal cord injury (SCI) characterized by a sudden increase in sympathetic activity below the level of the SCI. Here we report on the temporal HR response to an episode of unintentional boosting during a validated field-based exercise performance test in an athlete with tetraplegia.An athlete with SCI (C6 motor-complete, sensory-incomplete) completed a 20 ×20 m repeated sprint field test on two consecutive days. During the 13th sprint on day 2, the athlete unintentionally boosted via bladder overdistension. Average HR when boosted (i.e., sprints 14-20) was considerably higher than before boosting (141 ± 4 vs 116 ± 7 bpm) and compared with corresponding sprints on day 1 (141 ± 4 bpm vs 120 ± 1 bpm). Average time to complete 20 m sprints when boosted was also faster than the corresponding sprints on day 1 (6.70 ± 0.05 s vs 6.87 ± 0.05 s).This case report highlights the immediate effect of boosting on HR and field-based exercise performance and supports the suggestion that exercise performance in athletes with SCI is limited by cardiovascular capacity.

A 20×20m repeated sprint field test replicates the demands of wheelchair rugby.

OBJECTIVES: To assess the physiological responses to, and the agreement between, a 20×20m repeated sprint field test and wheelchair rugby game play, as well as the reliability of the test. DESIGN: Cross-sectional and longitudinal. METHODS: Heart rate (HR), blood lactate ([La-]B), and ratings of perceived exertion (RPE) were collected in nineteen elite wheelchair rugby athletes before, during, and after a 20×20m repeated sprint field test and game play. Times to complete 5, 10, and 20m during the field test were also collected. RESULTS: Peak HR and peak [La-]B were positively correlated during the field test (r=0.470, p=0.043), as were peak HR and peak speed (r=0.493, p=0.031), and peak [La-]B and peak speed (r=0.559, p=0.013). During game play, peak [La-]B was correlated with peak RPE (rho=0.703, p=0.001). Intra-class correlations (ICCs) between the field test and game play were significant for peak HR (ICC=0.922, p<0.001) and peak [La-]B (ICC=0.845, p<0.001). Bland-Altman analysis revealed good agreement between HR and [La-]B obtained during the field test and game play and excellent between-day reliability of the 20×20m sprint test. CONCLUSIONS: The physiological demands of a 20×20m repeated sprint field test are similar to those of elite wheelchair rugby game play and the test is highly reliable. This simple to implement field test may be useful as a component of team selection and in assessing the effectiveness of training interventions or monitoring athletes across training phases.

Boosting in Elite Athletes with Spinal Cord Injury: A Critical Review of Physiology and Testing Procedures.

Many individuals with spinal cord injury (SCI) experience autonomic dysfunction, which can have major implications on heart rate and blood pressure responses to exercise, and consequently athletic performance. Athletic performance may be improved by the induction of autonomic dysreflexia ('boosting'), a dangerous and sometimes life-threatening condition. Here, we review the autonomic response to exercise in individuals with SCI and the current testing methods for boosting, and examine the potential for autonomic testing to be used in the classification of SCI athletes. Given the difficulties associated with researching the effects of boosting, only three studies have compared the physiological performance of elite athletes in the boosted and unboosted state. These studies found athletes had an improved performance of ~7 to 10% in the boosted state. Blood pressure, heart rate, oxygen consumption, and circulating catecholamines were also higher in the boosted state. Although 27.1% of athletes believe that boosting was common in their sport, no athlete has ever tested positive for boosting at an event sanctioned by the International Paralympic Committee. Athletes with SCI competing in sports that have a high cardiovascular demand/aerobic component may experience the greatest benefit of boosting. Boosting improves athletic performance even at blood pressure levels well below the current threshold for disqualification set by the International Paralympic Committee, a level at which individuals with SCI are putting their health and lives at serious risk.

Peak heart rates and sympathetic function in tetraplegic nonathletes and athletes.

PURPOSE: To examine differences in peak heart rate (HR) and measures of sympathetic function between nonathletes and athletes with chronic, motor-complete, cervical spinal cord injury (SCI). METHODS: Eight nonathletic men with SCI (C4-C7; age 47 ± 9 yr, with injury duration of 16 ± 9 yr) and 13 athletic men with SCI (C5-C8; age 37 ± 8 yr, with injury duration of 16 ± 6 yr) participated in the study. Measures of sympathetic function included palmar sympathetic skin responses (SSR) to median nerve stimulation, and systolic (SBP) and diastolic (DBP) blood pressure responses to a passive sit-up test. Peak HR responses were assessed during a maximal exercise test. RESULTS: Compared to the athletic group, the nonathletic group exhibited lower peak HR (102 ± 34 vs 161 ± 20 bpm, P < 0.001) and average SSR scores (0.13 ± 0.35 vs 2.41 ± 1.97, P = 0.008), along with greater reductions in SBP and DBP in response to passive sit-up (SBP: -22 ± 10 vs -9 ± 12 mm Hg, P = 0.019; DBP: -18 ± 8 mm Hg vs -4 ± 9 mm Hg, P = 0.003). On the basis of the criteria for orthostatic hypotension (OH) (drop in SBP ≥ 20 mm Hg or DBP ≥ 10 mm Hg), 88% and 23% of nonathletes and athletes had OH. CONCLUSIONS: Attenuated peak HR in nonathletic individuals with tetraplegia may be secondary to impairments in sympathetic function including absent SSR and OH. Furthermore, the degree of preserved sympathetic function documented in tetraplegic athletes may suggest a predisposition to engage in high-performance sports. Collectively, our findings provide novel insight into the importance of the sympathetic nervous system for exercise performance.

Refined assessment of blood pressure instability after spinal cord injury.

BACKGROUND: This study determined whether the Autonomic Dysfunction Following Spinal Cord Injury (ADFSCI) questionnaire, a measure of self-reported frequency and severity of symptoms during hypo- and hypertensive episodes, correlates with blood pressure (BP) instability. In addition, test-retest reliability of the ADFSCI questionnaire was assessed. METHODS: Thirty individuals with spinal cord injury (SCI) (aged 42±12 years; level of lesion = C3-L1; American Spinal Injury Association Impairment Scale = A-C; lesion duration = 1 month to 30 years after injury) participated in this study. Twenty-four-hour ambulatory BP monitoring (ABPM) was used to assess BP instability. ABPM recorded systolic BP (SBP), diastolic BP (DBP), and heart rate at 15-minute intervals during the daytime and 1-hour intervals during the nighttime. Test-retest reliability was performed by completion of the ADFSCI questionnaire on 2 occasions (i.e., 9±4 days in between). RESULTS: Individuals with SCI who self-reported autonomic dysreflexia (AD) episodes showed significantly higher SBP coefficient of variation (CV) (14%) and more AD events (n = 11) than individuals who reported never having AD symptoms (CV = 9%; AD events = 1). Both the number of AD events over the 24-hour period and the BP variability (SBP CV) were significantly related to the patients' self-reported total AD score (rho = 0.522, P = 0.005; rho = 0.584, P = 0.001, respectively) and daily AD frequency (rho = 0.553, P = 0.003; rho = 0.586, P = 0.001, respectively). Conversely, no significant correlations existed between the number of hypotensive events over the 24-hour period and self-reported frequency and severity in the ADFSCI questionnaire. CONCLUSIONS: This study provides evidence that ABPM offers a strong clinical basis for documenting and understanding BP instability, such as AD, and related symptoms in individuals with SCI.

Physical exercise improves arterial stiffness after spinal cord injury.

OBJECTIVE/BACKGROUND: Aortic pulse wave velocity (PWV), the gold-standard assessment of central arterial stiffness, has prognostic value for cardiovascular disease risk in able-bodied individuals. The aim of this study was to compare aortic PWV in athletes and non-athletes with spinal cord injury (SCI). DESIGN: Cross-sectional comparison. METHODS: Aortic PWV was assessed in 20 individuals with motor-complete, chronic SCI (C2-T5; 18 ± 8 years post-injury) using applanation tonometry at the carotid and femoral arterial sites. Ten elite hand-cyclists were matched for sex to 10 non-athletes; age and time since injury were comparable between the groups. Heart rate and discrete brachial blood pressure measurements were collected throughout testing. OUTCOME MEASURES: Aortic PWV, blood pressure, heart rate. RESULTS: Aortic PWV was significantly lower in athletes vs. non-athletes (6.9 ± 1.0 vs. 8.7 ± 2.5 m/second, P = 0.044). There were no significant between-group differences in resting supine mean arterial blood pressure (91 ± 19 vs. 81 ± 10 mmHg) and heart rate (60 ± 10 vs. 58 ± 6 b.p.m.). CONCLUSION: Athletes with SCI exhibited improved central arterial stiffness compared to non-athletes, which is in agreement with the previous able-bodied literature. This finding implies that chronic exercise training may improve arterial health and potentially lower cardiovascular disease risk in the SCI population.