The objective of the present study was to compare a group-mediated cognitive behavioral (GMCB) physical activity intervention with traditional exercise therapy (TRAD) upon select social cognitive outcomes in sedentary knee osteoarthritis (knee OA) patients. A total of 80 patients (mean age = 63.5 years; 84% women) were recruited using clinic and community-based strategies to a 12-month, single-blind, two-arm, randomized controlled trial. Mobility-related self-efficacy, self-regulatory self-efficacy (SRSE), and satisfaction with physical function (SPF) were assessed at baseline, 3, and 12 months. Results of intent-to-treat 2 (Treatment: GMCB and TRAD) × 2 (Time: 3 and 12 month) analyses of covariance yielded significantly greater increases in SRSE and SPF (P < 0.01) relative to TRAD. Partial correlations revealed that changes in SRSE and SPF were significantly related (P < 0.05) to improvements in physical activity and mobility at 3 and 12-months. The GMCB intervention yielded more favorable effects on important social cognitive outcomes than TRAD; these effects were related to improvements in physical activity and mobility.

Many balance assessments have been created to identify causes and outcomes of older adult falls, and in turn, help health care providers better assess fall risk. The Activities-Specific Balance Confidence Scale (ABC), Timed Up-and-Go (TUG), Berg Balance Scale (BBS), and Fullerton Advanced Balance Scale (FAB) have been developed to assess physical function and fear of falling. Few studies have considered age as a moderator of the sensitivity of these four tests. PURPOSE: The aim was to identify if the sensitivity of the BBS, FAB, TUG, and ABC, changed as a function of age group (60-79 vs. 80-100) for retrospective falls. METHODS: Forty-six community-dwelling older adults (mean age 79.1±10.2 years) were recruited from multiple facilities and asked how many times they had fallen in the past six months. Next, the ABC, TUG, BBS, and FAB were administered in random order to assess the participants’ fear of falling, mobility, and balance. Logistic regression was used to determine the discriminative power of these tests related to falls. Logistic regression models had a binary outcome of self-reported history of at least one fall versus no falls. Receiver operating characteristics (ROC) curves were calculated, as well as the corresponding area under the curve (AUC). Specificity and sensitivity were calculated by age group (60-79 and 80-100). RESULTS: While the ABC, TUG, BBS, and FAB were significantly correlated with each other, their ability to discriminate fallers from non-fallers was poor (AUC = 0.366, 0.554, 0.426, and 0.437, respectively). Most models were better suited to determine non-fallers as opposed to fallers, indicated by a larger specificity than sensitivity. For all outcome measures, the sensitivity was 25.0% for 60-79 years and 37.7% for 80-100 years. The specificity was 100.0% for all outcome measures for 60-79 years, and was ≤68.8% for 80-100 years. CONCLUSIONS: Sensitivity, while poor in both age groups, was greater in the older group. Based on the present data we suggest pairing these tools with other measures to reliably assess and provide a total fall risk prediction.

PURPOSEWhile female hormones and high levels of aerobic fitness may offer a protective advantage against arterial stiffness in young women, short stature may negate this benefit. Our goals were to identify the key determinates of augmentation index (AIx) and investigate the influence that cyclic fluctuations of estradiol and progesterone have on ventricular‐vascular coupling in young healthy women.METHODWe assessed the relationship between maximal aerobic capacity (VO2max) and AIx standardized to 75 beats per minute (AIx@75 BPM). Twenty two nulliparous women taking either Loestrin (n=5), Ortho‐cyclen (n=5), or no contraceptive (n=12) underwent graded exercise testing and applanation tonometry of the radial artery to measure VO2max and AIx, respectively, during low hormonal status (±48h menses). Subsequently, AIx@75 BPM was measured at days 7, 14, and 21 post‐menses. Saliva was collected for analysis of estradiol and progesterone at all 4 time points.RESULTSIn all subjects, there was a statistical difference in AIx between mid‐follicular and early luteal phases (P <0.01), and between late luteal and early follicular phases (P<0.05). AIx was strongly and negatively associated with relative aerobic fitness (R2=.42, P<0.0001), and an additional 17% of this relationship was explained when corrected for height (R2=.69, P<0.0001). 14% of the variation in AIx@75 BPM was further explained by no contraceptive use, body composition, and peripheral diastolic blood pressure.CONCLUSIONSAIx fluctuates inversely with estradiol concentrations throughout the menstrual cycle. High aerobic capacity is associated with favorable AIx and may offer a mechanism that protects ventricular‐vascular coupling efficiency from deleterious variables such as short stature, age, and impedance mismatch. These results underscore the importance of regular exercise for women for enhanced heart and vascular health, especially as they approach menopause.

Maximal oxygen consumption ([Formula: see text]max) measured by cardiopulmonary exercise testing (CPX) is the gold standard for assessment of cardiorespiratory fitness. Likewise, cardiovascular magnetic resonance (CMR) is the gold standard for quantification of cardiac function. The combination of CPX and CMR may offer unique insights into cardiopulmonary pathophysiology; however, the MRI-compatible equipment needed to combine these tests has not been available to date. We sought to determine whether CPX testing in the MRI environment, using equipment modified for MRI yields results equivalent to those obtained in standard exercise physiology (EP) lab. Ten recreationally trained subjects completed [Formula: see text]max tests in different locations; an EP laboratory and an MRI laboratory, using site specific equipment. CMR cine images of the heart were acquired before and immediately after maximal exercise to measure cardiac function. Subjects in all tests met criteria indicating that peak exercise was achieved. Despite equipment modifications for the MRI environment, [Formula: see text]max was nearly identical between tests run in the different labs (95% lower confidence limit (LCL)  =  0.8182). The mean difference in [Formula: see text]max was less than 3.40 ml (kg/min)(-1), within the variability expected for tests performed on different days, in different locations, using different metabolic carts. MRI performed at rest and following peak exercise stress indicated cardiac output increased from 5.1  ±  1.0 l min(-1) to 16.4  ±  5.6 l min(-1), LVEF increased from 65.2  ±  3.3% to 78.4  ±  4.8%, while RVEF increased from 52.8  ±  5.3% to 63.4  ±  5.3%. Regression analysis revealed a significant positive correlation between [Formula: see text]max and stroke volume (R  =  0.788, P  =  0.006), while the correlation with cardiac output did not reach statistical significance (R  =  0.505, P  =  0.137). [Formula: see text]max CPX testing can be effectively performed in the MRI environment, enabling direct combination of physiological data with advanced post-exercise imaging in the same test session.

Spirulina may increase people's ability to resist mental and physical fatigue. This study tested that hypothesis in a randomized, double blinded, placebo controlled study in men. After 1week, a 3g/day dose of spirulina produced a small, but statistically significant increase in exercise output (Kcals consumed in 30min exercise on a cross trainer machine). A mathematical based mental fatigue test showed improved performance 4h after the first time of supplementation as well as 8weeks later. Similarly, a subjective survey for a sense of physical and mental fatigue showed improvement within 4h of the first supplementation as well as 8weeks later. These results show that spirulina intake can affect fatigue in men.

Recent evidence has shown that self-paced VO2max treadmill tests (SPV) can produce similar VO2-power relationships as traditional incremental treadmill tests. The endspurt during the last stage of SPV may be a surrogate for a supramaximal test. Pairing the SPV VO2-power relationship and endspurt may allow for the calculation of a correlated measure to maximal accumulated oxygen deficit (MAOD) and the potential to determine aerobic power and anaerobic capacity in a single task. PURPOSE: To determine if SPV can produce a correlated measure to MAOD using data available only from the SPV test. METHODS: Seventeen male subjects (age 25 ± 5 years, VO2max 62.3 ± 9.2 ml*kg-1*min-1) completed four submaximal exercise tests to determine a VO2-power relationship. MAOD was measured during a supramaximal exercise bout. An SPV was completed on an automated treadmill with VO2-power relationship determined from stages 2-4. For both relationships, y-intercept was set at 5.1 ml*kg-1*min-1. Accumulated oxygen deficit (AOD) was determined for SPV stage 5 as the sum of each 15 second O2 deficit until estimated O2 demand fell below O2 uptake. Peak power was taken as the highest 15 second average throughout. VO2 was calculated using 15 second averages. RESULTS: Eight subjects produced an endspurt during stage 5 of SPV and were included in the analysis. The supramaximal exercise test lasted 2.48 ± 0.40 min and MAOD averaged 39.2 ± 7.1 ml*kg-1. VO2-power relationship slopes for submaximal stages (0.2507 ± 0.0203) and SPV stages (0.2597 ± 0.0200) were significantly different (p = 0.043) and significantly correlated (r = 0.828, p = 0.011). However, SPV stage 5 AOD (104.9 ± 114.8 ml*kg-1) and peak power (271 ± 25 watts) were not correlated with MAOD (r = 0.637, p = 0.090; r = 0.519, p = 0.187, respectively). CONCLUSIONS: Not all subjects choose to produce their maximal power upon initiation of stage 5 and thus do not produce an endspurt. Measures from stage 5 of SPV hypothesized to estimate anaerobic capacity did not correlate with MAOD. It is possible that the ability to alter power output throughout SPV, akin to overland running, may have altered the VO2-power relationship enough to reduce the validity of the accumulated oxygen deficit measure. Accordingly, it appears that anaerobic capacity cannot be estimated using a single SPV treadmill test.

Recent reports have indicated that resistance exercise training performed absent an aerobic exercise program may increase arterial stiffness. Our purpose was to compare the augmentation index (AIx) and left ventricular wasted pressure energy (LVEW) as markers of arterial stiffness and ventricular‐vascular coupling efficiency in young aerobic (AT) and resistance (RT) trained athletes. We also investigated the relationship between muscle sympathetic nerve activity (MSNA) and AIx to determine if sympathetic outflow could explain any observed differences in arterial stiffness.Methods: MSNA (via microneurography of the peroneal nerve) was measured in 15 male subjects (8 RT, 7 AT). Aortic pressure waveforms were synthesized using applanation tonometry of the radial artery to derive AIx and LVEW values.Results: RT subjects had greater AIx (12 ± 3 vs. ‐7 ± 2; P<0.01), LVEW (429 ± 111 vs. ‐360 ± 77; P<0.01) and MSNA burst incidence (109 ± 23 vs. 31 ± 5; P<0.01) than AT subjects. MSNA burst incidence was also significantly related to AIx in all subjects (R2=0.61; P<0.01).Conclusions: A positive association was found between MSNA and AIx in young males. Furthermore, a history of RT is associated with increased arterial stiffness and elevated sympathetic outflow.

The use of graded maximal exercise tests for measuring maximal oxygen consumption (VO2max) is common practice in both cardiopulmonary rehabilitation settings and in sports medicine research. Recent alterations of common testing protocols to allow for self-selected work rates (SPV) have elicited V˙O2max values similar to or higher than more traditional style protocols (TP). Research is lacking in the delivery of the SPV protocol using a treadmill modality. The purpose of the study was to examine the validity of an SPV using an automated treadmill for measuring cardiorespiratory fitness.Thirteen experienced endurance runners completed three maximal exercise tests on a treadmill. Oxygen consumption was measured using a computerized system and averaged more than 30-s time periods. SPV was completed using an automated treadmill that consisted of a sonar range finder, microcontroller, and customized computer software. Subject deviations from the middle of the treadmill belt resulted in rapid, graded increases or decreases in speed. TP was completed on the same treadmill without the use of the automated software. A verification phase protocol (VP) was used to verify if VO2 was maximal.Peak work rate achieved during SPV was significantly greater than that achieved during TP by 1.2 METs; P < 0.05, d = 0.564. Oxygen consumption was significantly greater in TP (64.9 ± 8.2 mL·kg·min) than SPV (63.4 ± 7.8 mL·kg·min); P < 0.005, d = 0.195.An automated treadmill allowed for the completion of SPV similar to what has been reported for cycling. SPV with an automated treadmill did not provide a higher VO2max than TP despite higher work rates.

PURPOSE:The use of graded maximal exercise tests for measuring maximal oxygen consumption (VO2max) is common practice in both cardiopulmonary rehabilitation settings and in sports medicine research. Recent alterations of common testing protocols to allow for self-selected work rates (SPV) have elicited V˙O2max values similar to or higher than more traditional style protocols (TP). Research is lacking in the delivery of the SPV protocol using a treadmill modality. The purpose of the study was to examine the validity of an SPV using an automated treadmill for measuring cardiorespiratory fitness. METHODS:Thirteen experienced endurance runners completed three maximal exercise tests on a treadmill. Oxygen consumption was measured using a computerized system and averaged more than 30-s time periods. SPV was completed using an automated treadmill that consisted of a sonar range finder, microcontroller, and customized computer software. Subject deviations from the middle of the treadmill belt resulted in rapid, graded increases or decreases in speed. TP was completed on the same treadmill without the use of the automated software. A verification phase protocol (VP) was used to verify if VO2 was maximal. RESULTS:Peak work rate achieved during SPV was significantly greater than that achieved during TP by 1.2 METs; P < 0.05, d = 0.564. Oxygen consumption was significantly greater in TP (64.9 ± 8.2 mL·kg·min) than SPV (63.4 ± 7.8 mL·kg·min); P < 0.005, d = 0.195. CONCLUSION:An automated treadmill allowed for the completion of SPV similar to what has been reported for cycling. SPV with an automated treadmill did not provide a higher VO2max than TP despite higher work rates.

The prevalence of barefoot running has increased over the past decade. In response, several equipment manufacturers have produced “minimalist” shoes that allow for the subjective feel of barefoot running while providing basic foot protection. Previous research indicates running in barefoot conditions, or with a minimalist shoe, may offer a biomechanical advantage. Anecdotal reports suggest such running conditions may improve race performance; however, research in this particular area has not been explored. PURPOSE: To examine differences in running performance, physiological variables, and psychological ratings of exertion and feeling during a race situation in a minimalist shoe (MS) versus traditional shoe (TS) in trained runners with minimalist shoe experience. METHODS: Fourteen male, trained runners engaged in a 2-mile time trial using either MS or TS. During the trial subjects controlled speed without knowing the pace they were running. Every half-mile subjects responded to the feeling scale (FS) and rating of perceived exertion (RPE). A qualitative questionnaire was also given post run to gather information on motivation and subjective responses to running. The perception of performance (POP) scale was used to examine subject perception of their running performance. Time to completion (TTC) of the race trial was also measured, as were physiological variables relating to exercise intensity: heart rate (HR), and oxygen (VO2) and carbon dioxide (CO2) utilization. RESULTS: There were no significant differences in TTC or RPE between MS and TS trials. Compared with TS, the MS trial scored significantly higher on the FS (p <0.05, 4.47 ± 1.45 v. 0.61 ± 1.71) and POP (p < 0.05, 0.33 ± 1.04 v. -0.33 ± 0.84). CONCLUSIONS: Runners trained in both traditional and minimalist running shoes show psychological edges in minimalist shoes during competitive runs. When compared with traditional shoes, trained runners who race in a minimalist shoe report feeling better, and running easier, at all levels of exertion despite no improvements in race time.

Androgen deprivation therapy (ADT) plays a critical role in the treatment of prostate cancer (PC), the most common malignancy in American men. ADT results in diverse physiological effects impacting health and quality of life. PURPOSE: To characterize the cardio-metabolic phenotype of men with prostate cancer prior to ADT, define the heterogeneity of this population, and identify those at greater risk of complications who may benefit from dietary and fitness interventions. METHODS: Metabolic evaluation of ventilatory gas exchange was completed in a sample of 19 men with prostate cancer age range of 49- 74 years (mean and SD; 62.9 ± 7.6) immediately prior to initiation of ADT. Patient body mass index (BMI) was calculated, range 21.9 to 39.7 (29.2 ± 4.1 kg/m2). Peak oxygen consumption (V[Combining Dot Above]O2peak) data was collected via treadmill Bruce protocol to volitional exhaustion. Cardiopulmonary testing measures including respiratory exchange ratio (RER), O2 pulse, max heart rate (HRmax), and test duration, were recorded. RESULTS: V[Combining Dot Above]O2peak was measured in PC patients ranged from 20.4 ml/kg/min to 35.2 ml/kg/min (27.6 ± 4.8 ml/kg/min). Metabolic parameters, RER (1.06 ± 0.1) and O2 pulse (15.7 ± 3.2) were measured at peak exercise. Test duration (9.2 ± 1.6 min) resulted in average peak heart rate (156.9 ± 15.1 bpm). CONCLUSIONS: VO2peak ranged in PC patients from 5th percentile to the 75th percentile for aged-matched men, according to ACSM Guidelines. Patients initiating ADT vary significantly in their cardio-metabolic phenotype. Although degradation of cardiopulmonary health related to ADT is being investigated and reported, it remains imperative to define objective strategies to identify men at risk of cardiopulmonary decline and metabolic complications with ADT. This data will allow the design of effective fitness interventions at the initiation of ADT that will promote healthy cancer survivorship. Supported by Pelotonia/The OSU Comprehensive Cancer Center.

Self-regulatory self-efficacy (SRSE) beliefs have been identified as important determinants of adoption and maintenance of moderate to vigorous physical activity (MVPA) behavior. Given the established benefits of MVPA in managing knee osteoarthritis (KOA), delineating the potential mediational role of SRSE upon PA participation in KOA patients is important in guiding future PA promotion efforts. PURPOSE: The purpose of the single-blind, randomized controlled Improving Maintenance of Physical Activity-Pilot (IMPACT-P) trial was to evaluate the comparable efficacy of traditional exercise training (TRAD) and a group-mediated cognitive-behavioral PA intervention (GMCB) for improving objectively-determined PA in sedentary, older, KOA patients. In the current study, we evaluated the role of SRSE in mediating change in MVPA at a 3-month follow-up assessment. METHODS: A total of 80 KOA patients (M age = 64 years) were randomly assigned to the GMCB (n = 40) or the TRAD (n = 40) interventions. Measures of SRSE and MVPA were obtained at baseline and 3 month follow-up assessments. RESULTS: After establishing the required univariate pathways between the GMCB intervention (p < .01), SRSE (p < .01), and MVPA (p < .01), multiple regression analysis testing the composite model was conducted to test mediation while controlling for age and gender. Results revealed that SRSE partially mediated the effect of the GMCB intervention on change in MVPA at 3 Months. CONCLUSIONS: Findings from the IMPACT-P trial suggest that SRSE serves as an independent, partial mediator of the effects of the GMCB intervention on change in MVPA. Supported by NIH/NIAMS R21 AR054595

The purpose of this study was to examine the affective responses to acute resistance exercise (RE) performed at self-selected (SS) and imposed loads in recreationally trained women. Secondary purposes were to (a) examine differences in correlates of motivation for future participation in RE and (b) determine whether affective responses to RE were related to these select motivational correlates of RE participation. Twenty recreationally trained young women (mean age = 23 years) completed 3 RE sessions involving 3 sets of 10 repetitions using loads of 40% of 1 repetition maximum (1RM), 70% 1RM, and an SS load. Affective responses were assessed before, during, and after each RE session using the Feeling Scale. Self-efficacy and intention for using the imposed and SS loads for their regular RE participation during the next month were also assessed postexercise. Results revealed that although the SS and imposed load RE sessions yielded different trajectories of change in affect during exercise (p < 0.01), comparable improvements in affect emerged after RE. Additionally, the SS condition was associated with the highest ratings of self-efficacy and intention for future RE participation (p < 0.01), but affective responses to acute RE were unrelated to self-efficacy or intention. It is concluded that acute bouts of SS and imposed load RE resulted in comparable improvements in affect; recreationally trained women reported the highest self-efficacy and intention to use the load chosen in SS condition in their own resistance training; and affective responses were unrelated to motivational correlates of resistance training.

The modified-Astrand protocol is used often in research when measuring VO2max, particularly in trained runners. The starting speed of the protocol is subjectively chosen by the researcher and varies based on training and racing history of the subject or subject population. This process results in test durations that may or may not meet the 10 minute test end point recommendation. There is currently no recommendation of an objective intensity for beginning the modified-Astrand protocol to achieve a proper test duration of 10 minutes in well-trained runners. PURPOSE: To determine an objective intensity for beginning the modified-Astrand protocol in an effort to elicit a test duration of 10 minutes. METHODS: Thirteen well-trained runners and triathletes (mean VO2max = 64.9ml·kg-1·min-1) underwent an incremental treadmill test to exhaustion utilizing the modified-Astrand protocol. VO2 was averaged every 30 seconds throughout testing. VO2max was confirmed using a verification phase protocol. Correlations were determined between test duration and both steady state VO2 during the first stage (as a percentage of VO2max, SSVO2) and steady state heart rate during the first stage (as percentage of maximal heart rate, SSHR). Bivariate regression was used to predict test duration from SSVO2 and SSHR. RESULTS: All subjects achieved VO2max based on results of the verification phase test. SSVO2 was significantly related to the duration of the test (r = -.837, p < .001, r2 = .700). SSHR was also significantly related to the duration of the test (r = -.791, p = .001, r2 = .626). Bivariate regression resulted in the determination that an initial work rate eliciting 65% of VO2max or 83% of maximal heart rate will likely result in a test duration of 10 minutes (SSVO2 SEE = .937 min, SSHR SEE = 1.27 min). CONCLUSIONS: It is suggested that an initial workrate of 65% VO2max or 83% of maximal heart rate is chosen when using the modified-Astrand protocol with well-trained runners in order to attain the recommended test duration of 10 minutes. Supported by The Ohio State University Alumni Grant for Graduate Research and Scholarship

Advances in magnetic resonance imaging (MRI) equipment and techniques allow for cardiac function and blood flow quantification immediately following maximal aerobic exercise. Previous MRI studies have tested cardiovascular and blood flow adaptations to supine cycle ergometer exercise. PURPOSE: Using an MRI-compatible treadmill we utilized Cine and Phase-contrast Magnetic Resonance Angiography (PCMRA) imaging techniques to evaluate differences in cardiac function and blood flow in individuals before and immediately after a maximal exercise test. METHODS: Descriptive maximal oxygen consumption (VO2max) data was collected via treadmill Bruce protocol. VO2max was 34.3 ± 3.3 ml/kg/min, 51.0 ± 9.7 ml/kg/min, and 70.3±5.5 ml/kg/min in untrained (n=10), recreationally trained (n=10) and elite (n=2) subjects, respectively. MRI scanning was performed using a 1.5-T magnet, (MAGNETOM, Avanto, Siemens Healthcare, Germany). Elapsed time from cessation of maximal exercise to Cine and PCMRA acquisitions was 36.0 ± 3.8s, and imaging was completed by 67.5 ± 5.5s after exercise. RESULTS: Left ventricle myocardial mass was significantly (p=0.028) higher in elite (141.4±51.5 g) vs recreationally trained subjects (92.8±15.2 g). Stroke volume measures after maximal exercise were significantly higher (p=0.001) in the elite (161.9±12.6 ml) vs both untrained (87.8 ± 11.4 ml), and recreational (99.6 ± 22.5 ml) groups. Similarly, cardiac output was elevated (p=0.043) in elite (22.4±2.7 L/min) compared with both untrained (15.4±2.2 L/min) and recreationally trained subjects (16.4±3.6 L/min). There were no differences observed in ejection fraction between the three groups (74.9 ± 6.0 ml, 78.5 ± 4.8 ml, 73.2±5.2 ml) untrained, recreational, and elite, respectively. CONCLUSIONS: MRI has not been previously used to compare the cardiovascular response following maximal treadmill exercise in untrained vs recreationally trained vs elite individuals. This new technology offers unique clinical, performance, and research opportunities for assessment of cardiovascular health, training adaptations to exercise stress, and cardiopulmonary disease management.

Accelerometers have been evaluated extensively regarding their ability to assess postural sway. Horizontal center of mass (COM) accelerations have been reported to be positively associated fall risk in older adult populations. In fact, we previously reported that an accelerometer-based balance assessment (ABA) was superior to select clinical measures at retrospectively discriminating fallers from non-fallers. PURPOSE: Understanding that a retrospective analysis of fall risk is inherently flawed, we aimed to prospectively evaluate the ABA. METHODS: Ninety-three independent community-living otherwise healthy older adults (age 86±6 years) were recruited from multiple facilities. For the baseline assessment, participants completed the ABA (8 static balance tasks), Timed Up-and-Go (TUG), Berg Balance Scale (BBS), and the Activities-Specific Balance Confidence (ABC) Scale. Participants were then called weekly for 12 months to evaluate falls after the baseline assessment. We then compared outcomes from the ABA and clinical assessments between participants who never fell, participants who fell once, and participants who fell two or more times during the follow-up period. RESULTS: During the 12-month follow-up, 22/93 (24%) of the participants fell once and 32/93 (34%) fell at least twice. The average root mean square of the horizontal COM accelerations across the 8 ABA static balance conditions for non-fallers, one time fallers, and multiple fallers (0.0126 ± 0.0049 g, 0.0122 ± 0.0030 g, and 0.0129 ± 0.0042 g, respectively) were statistically similar. Likewise, there were no significant differences between non-fallers, one time fallers, and multiple fallers with respect to the TUG (15.7 ± 12.0 s, 17.1 ± 10.2 s, and 12.8 ± 4.7 s, respectively), BBS (46.7 ± 7.4, 45.1 ± 10.1, and 47.3 ± 5.1, respectively), or the ABC Scale (69.6 ± 19.1, 68.0 ± 16.2, and 65.8 ± 18.1, respectively). CONCLUSIONS: In this 12-month prospective study, 58% of our study population fell at least once, but baseline performance on the ABA, TUG, BBS, and ABC Scale was not significantly associated with future single or multiple falls.

Clinicians are in need of valid and objective measures of postural sway. Accelerometers have been shown to be suitable alternatives to expensive and stationary force plates. We evaluated the test-retest reliability and balance task discrimination capability of a new wireless triaxial accelerometer (YEI 3-Space Sensor). Four testing conditions (eyes open or closed, while on a firm or compliant surface) were used to progressively challenge the static balance of 20 healthy male (n = 8) and female (n = 12) older adults (mean age 81 ± 4.3 y). Subjects completed 2 blocks of three 30-second trials per condition. The accelerometer was positioned on the lower back to acquire mediolateral (M-L) and anterior-posterior (A-P) accelerations. Intraclass correlation coefficients were all good to excellent, with values ranging from .736 to .972 for trial-to-trial and from .760 to .954 for block-to- block. A significant stepwise increase in center of mass acceleration root mean square values was found across the 4 balance conditions (F[1.49, 28.26] = 39.54, P < .001). The new accelerometer exhibited good to excellent trial-to-trial and block-to-block reliability and was sensitive to differences in visual and surface conditions and acceleration axes.

Absence of the dystrophin protein in the mdx mouse leads to myofiber necrosis and oxidative stress. Unmonitored wheel running exercise has been shown to accelerate a cascade of cellular events that results in increased dystrophic symptoms. Examining the influence of monitored and prescribed treadmill exercise on both muscle damage and markers of oxidative stress will help to enhance the understanding of how these pathological mechanisms influence dystrophic symptoms, and improve endpoint measures of disease state. PURPOSE: To test the influence of a four-week treadmill exercise program on oxygen consumption, oxidative stress, and muscle fibrosis in the mdx mouse in order to monitor prescribed exercise treatment effectiveness. METHODS: Starting at four weeks of age, mdx mice were subjected to four weeks of twice-weekly treadmill exercise for 30 minutes per bout (Ex, n=7). Sedentary mdx (Sed, n=9) and wild-type (WT, n=5) served as non-exercised controls. Whole-animal oxygen consumption, as well as a marker of oxidative stress - reduced glutathione level, and myofiber necrosis and fibrosis was assessed in individual muscles. RESULTS: At four weeks of age there was a significant difference in time to exhaustion (TTE) between mdx and WT (16.5 ± 1.2 mins vs. 24.8 ± 0.9 mins, p < 0.01). Following the four weeks of exercise treatment, compared with SED mice, EX mice had significantly lower baseline O2 consumption (42.4 ± 6.0 ml•kg-1•min-1 vs. 79.2 ± 12.6 ml•kg-1•min-1, p < 0.05) and TTE (18.8 ± 2.6 mins vs. 25.3 ± 6.4 mins, p < 0.05). Quadriceps muscles from EX mice exhibited significantly higher hydroxyproline deposition than SED mice (2.5 ± 0.3 μg/mg vs. 1.1 ± 0.2 μg/mg, p < 0.01) and an increased ratio of reduced glutathione protein (27.73 ± 3.4 vs. 18.12 ± 2.3, p < 0.05 ). CONCLUSIONS: Exercised mdx mice exhibit decreased exercise capacity, increased fibrosis, but had improved oxidative profiles in select skeletal muscles. Oxidative stress might also prove to be a useful outcome measure to monitor disease progression as a response to exercise stress, and certain dystrophic muscle adapts favorably to oxidative stress brought on by exercise. This study supports the need for further investigation of exact intensity levels of prescribed treadmill exercise, and how it affects dystrophic disease differently than other modalities.

INTRODUCTION:We tested how a treadmill exercise program influences oxygen consumption, oxidative stress, and exercise capacity in the mdx mouse, a model of Duchenne muscular dystrophy.METHODS:At age 4 weeks mdx mice were subjected to 4 weeks of twice-weekly treadmill exercise. Sedentary mdx and wild-type mice served as controls. Oxygen consumption, time to exhaustion, oxidative stress, and myofiber damage were assessed.RESULTS:At age 4 weeks, there was a significant difference in exercise capacity between mdx and wild-type mice. After exercise, mdx mice had lower basal oxygen consumption and exercise capacity, but similar maximal oxygen consumption. Skeletal muscle from these mice displayed increased oxidative stress. Collagen deposition was higher in exercised versus sedentary mice.CONCLUSIONS:Exercised mdx mice exhibit increased oxidative stress, as well as deficits in exercise capacity, baseline oxygen consumption, and increased myofiber fibrosis. Muscle Nerve 54: 110-117, 2016.

Falls among older adults represent a significant health concern due to the high number of incidents, the involvement of many different risk factors, and the consequential post-fall morbidity and mortality. Prospective studies are beneficial as they help to identify the causes and outcomes of falls in older adults, and in turn, help health care providers better assess fall risk. PURPOSE: The specific aim was to characterize fall information through a 12 month prospective fall study among older adults. METHODS: Ninety-three independent community-living otherwise healthy older adults (age 86±6 years) were recruited from multiple facilities. Participants were asked how many times they had fallen in the past six months. Participants were called weekly for 12 months to evaluate falls after the baseline assessment. The date, time, location, activity at the time of the fall, injuries, assistive device use, and medication changes were all recorded at each follow up call. Fall characteristic data were presented as percentages of total falls. RESULTS: At the time of testing, 36/93 participants (38.7%) self-reported at least one fall in the preceding six months. Of the 36 participants with a self-reported fall history, 24 (66.7%) fell at least once in the subsequent 12 months of follow-up. Of the 57 participants without a self-reported fall history, 30 (52.6%) fell at least once in the subsequent 12 months of follow-up. A majority of the 147 total falls occurred inside (78.2%) and/or at home (67.3%), and sometime between 6:00 a.m.-10:00 p.m. (83.0%). An injury was reported in 40.1% of the falls and 6.1% resulted in a fracture. Falls that occurred while using an assistive device comprised of 18.4%. Lastly, a recent medication change was found in 5.4% of the falls. CONCLUSIONS: Due to the high incidence of falls that occurred during the 12-month follow up period (many injurious) in those with and without a recent history of falls, this study suggests that greater precautions must be taken to ensure the safety of these older adults regardless of perceived fall risk. Given that most falls occurred at home during waking hours, it is advised that the home environment be evaluated more rigorously and appropriate preventive modifications made. It may also be prudent to further assess the proper use of assistive devices, as it is presently unclear whether the device contributed to a fall or if individuals already at an increased risk of falling use an assistive device.