Below are the final abstract submissions for the 2019 conference.
Title: Branched-chain amino acid supplements and exercise: an update
Authors: Matthew S. Kaspy & Tyler A. Churchward-Venne; Presenter: Matthew S. Kaspy
Abstract: Branched-chain amino acid (BCAA; leucine, isoleucine, and valine) supplements are widely consumed by athletes and fitness enthusiasts. Purported benefits of BCAA supplementation within the context of exercise include: 1) anabolic effects on skeletal muscle via enhanced stimulation of skeletal muscle protein synthesis (MPS) and/or reduced muscle protein breakdown, 2) expedited recovery of impaired muscle function and muscle soreness following exercise-induced skeletal muscle damage (EIMD), 3) delayed onset of central nervous system mediated fatigue, and 4) improved exercise performance. The ingestion of BCAAs stimulates increased MPS rates during recovery from resistance-type exercise, although less effectively than a complete high-quality protein. Supplementation with BCAAs appears to attenuate indirect markers (e.g. muscle performance, blood creatine kinase) of EIMD, although the underlying mechanisms for these effects are unclear. Despite a strong underlying rationale for how BCAAs may limit the development of central fatigue, there is limited evidence demonstrating that exercise performance in humans can be altered by nutritional manipulation with BCAA supplements. Based on the available evidence, BCAA supplements demonstrate limited efficacy in their capacity to stimulate increased MPS rates and enhance the accretion of skeletal muscle mass in humans or improve exercise performance. BCAA supplements may reduce indirect markers of EIMD and muscle soreness but there is currently a lack of direct evidence (e.g. Z-band streaming) that they reduce EIMD. Overall, there is a lack of strong evidence for the efficacy of BCAA supplements on exercise recovery, adaptation, or performance.
Title: The feasibility of measuring physical function and patient-reported outcomes across the surgical timeline in head and neck cancer.
Authors: Julia Daun, Dr. Rosemary Twomey, Dr. Joseph Dort, Dr. Lauren Capozzi, Dr. Trafford Crump, Dr. George Francis, Dr. T. Wayne Matthews, Dr. Shamir Chandarana, Dr. Rob Hart, Dr. Christiaan Schrag, Dr. Jennifer Matthews, Dr. C. David McKenzie, Dr. Harold Lau, Dr. S. Nicole Culos-Reed; Presenter: Julia Daun
Abstract: Purpose: Head and neck cancer (HNC) is the sixth most commonly diagnosed cancer world-wide. Physical activity enhances physical and psychosocial functioning of HNC patients. All HNC patients undergoing major surgery are managed by a multidisciplinary team that uses a postoperative care pathway; however, the current established protocols do not target the preoperative physical condition of patients. Prehabilitation is an intervention designed to use the waiting period before surgery to optimize the patient’s condition and may be a complementary addition to existing perioperative protocols. Methods: In phase I, using a mixed-methodological approach, a prospective cohort study will: 1) assess the feasibility of measuring physical functioning and patient-reported outcomes of surgical HNC patients across their clinical timelines; and 2) understand how exercise fits into the care pathway, by using a patient-oriented framework to conduct semi-structured interviews with a subset of these patients. Staff will also be interviewed to provide feedback on exercise prehabilitation logistics for the clinic setting. In phase II, an exercise prehabilitation intervention will be implemented, with feasibility as the primary outcome. Results: Data collection will take place between July and December 2019. Conclusion: This project aims to positively impact the quality of life of HNC patients as well as provide an innovative model for uptake by other tumour groups and clinical sites, for the implementation of exercise into standard cancer care.
Title: Osteoporosis knowledge, beliefs, and behaviours in older women who exercise
Authors: Kaitlyn Sobchuk, Tessa VanDerVeeken, Tak Fung, Patricia K. Doyle-Baker; Presenter: Kaitlyn Sobchuck
Abstract: Post-menopausal women may reduce their osteoporosis risk through appropriate diet and exercise behaviours. Eleven women who row with a mean (SD, ±) age of 55.7±2.4 were administered four surveys ((Osteoporosis Knowledge Assessment Tool -OKAT), (Osteoporosis Health Belief Scale -OHBS), (Godin Leisure Time Exercise Questionnaire, -PAB), and (Calcium Food Frequency Questionnaire -FFQC)) at T1 -baseline, T2 -education session, and T3 -four week follow up. During T1 demographics, and clinical risk factors (bone mineral density -BMD) were assessed and at T2 participants received a 2-hour educational session with their BMD and fracture risk scores (FRAX). The education session was participant driven and focused on their dietary intake and exercise questions beyond their rowing training. Descriptive statistics and a One-Way-Repeated-Measures ANOVA were used to compare the OKAT, OHBS, PAB, and FFQC scores across all three time points. A Pearson’scorrelation was used to determine if the BMD and FRAX score were associated with knowledge, beliefs, and protective behaviours. A significant time effect (p<0.001,), occurred from T1-T2 only on the OKAT score (T1 10.36±1.081; T2 14.91±0.513; T3 14.27±0.648; F(2,20) =15.607). The group mean survey scores (OHBS, PAB, FFQC) did not change between time. A strong positive correlation between FRAX hip score and weekly calcium (food sourced) was observed at T3 (r=0.828). Participants identified at follow up that they added load bearing exercise to their workouts and other calcium sources to their diets. In summary the intervention was effective at improving and maintaining general knowledge of osteoporosis, as well as some risk and protective behaviours.
Title: A Pilot Study Investigating Eccentric Loading and Bone Response: Using a Rabbit Protocol
Authors: Tessa VanDerVeeken, Dr. Tish Doyle-Baker, Dr. Brent Edwards; Presenter: Tessa VanDerVeeken
Abstract: Osteoporosis (low bone mineral density) is frequently managed and prevented with exercise intervention and drug therapy, however, the prevalence of osteoporosis in Canada is still increasing yearly. In general, bone responds to strain and loading through locomotion, jumping, and muscle contraction. Cell signaling is dependent on a combination of strain frequency, rate, distribution, and magnitude. This two-arm prospective exercise study will employ an animal model to quantify strain and bone response with and without commonly prescribed bisphosphonates. Six female, New Zealand white rabbits, will serve as their own control (N=12) in a six-week loading protocol where the right hindlimb acts the experimental (EL) group and the left hindlimb as the control (CL) group. EL will undergo a nerve-cuff electrode implantation around the femoral nerve to control the knee extensor muscles. The intervention protocol includes supramaximal, involuntary eccentric loading for five sets of ten contractions at the knee joint, for six weeks. A strain gauge attached to the motor lever connected to the tibia will measure load. At the end of the intervention, animals will be euthanized and bone mineral density and bone-volume density will be measured through DXA and micro-CT scans, respectively. Our research goal is to understand how bone responds to eccentric loading within a defined time frame. To the best of our knowledge, bone response to frequent eccentric loading in older female rabbits has not been quantified with the goal of designing an exercise intervention for osteoporosis reduction in post-menopausal women. This study will provide a framework for moving forward in the human model.
Title: Stand to Strengthen: Development of a multi-level intervention to reduce prolonged sitting in assisted living facilities
Authors: Lauren Voss, Jennifer L. Copeland; Presenter: Lauren Voss
Abstract: Prolonged sedentary time (ST) is associated with increased risk of cardiometabolic disease, impaired physical function, and mortality. Older adults accumulate large amounts of ST and low amounts of physical activity, which may compound the health risks. There is a dearth of research examining strategies to reduce ST among OA, especially among those within assisted living facilities (ALFs). The purpose of this study was to develop an evidence-informed intervention to reduce ST within ALFs. Stand to Strengthen was developed in three phases: 1) literature review 2) focus groups with AL residents 3) expert validation with ALF staff. The literature review suggested a multi-level approach would be more effective, incorporating all four levels of the social ecological model (individual, social, environmental, and organizational). Focus groups with AL residents (n = 31; 84% women; 83.5 ± 6.5 years) were conducted to gain an understanding of resident perspectives of ST as well as motivators and barriers to reducing ST. Themes identified in the focus groups included a common belief that not all sitting was “bad” for health. Pain and lack of opportunity were common barriers; a lifelong habit of moving and social engagement were considered motivators. Based on the results of 1 and 2, a list of potential intervention strategies were developed and presented to ALF staff (n = 16; 100% women) to gather feedback about feasibility. The resulting Stand to Strengthen intervention is evidence-based and co-created, with good potential for low-cost implementation and scale-up. Future research will examine effectiveness and optimal implementation strategies.
Title: Assessing sex-based differences in human muscle oxidative capacity using near-infrared spectroscopy
Authors: Jenny Zhang, Tom Tripp, Austin Beever, Martin MacInnis; Presenter: Jenny Zhang
Abstract: Background: Muscle oxidative capacity, the maximal rate at which skeletal muscles utilize oxygen to meet energetic demands, can be measured non-invasively with near-infrared spectroscopy (NIRS). The aims of this study were to determine (i) whether there are sex-based differences in muscle oxidative capacity for the vastus lateralis (VL) and medial gastrocnemius (MG) and (ii) the reliability of these measures. Methods: Participants (n=24) completed a ramp incremental VÌ‡O2max test and underwent a Dual-energy X-ray Absorptiometry scan to determine aerobic fitness relative to lean body mass (mL/kg LBM/min). Oxidative capacity of the VL and MG was measured twice for each muscle, from NIRS data collected during arterial occlusion following a brief exercise stimulus. Men and women were compared using independent t tests. Reliability was assessed using intraclass correlation coefficient (ICC) and coefficient of variation (CV). Results: Men (54.6±5.8 mL/kg LBM/min) and women (52.1±6.3 mL/kg LBM/min) had similar aerobic fitness when normalized to LBM (p=0.35). Differences in oxidative capacity between men (VL: 24.16±6.6 s; MG: 19.8±4.3 s) and women (VL: 22.7±4.8 s; MG: 32.5±12.5 s) were significant in the MG (p=0.005) but not in the VL (p=0.60). Reliability for the oxidative capacity measurements was moderate for the VL (ICC=0.66, p=0.01) and strong for the MG (ICC=0.83, p<0.001), and CVs were 16.3% and 18.3%, respectively. Conclusion: When properly matched for aerobic fitness, the oxidative capacity for the VL was similar between men and women, whereas men had greater oxidative capacity in their MG muscles. NIRS is a reliable method to assess oxidative capacity.
Title: Near-infrared spectroscopy (NIRS)-derived skeletal muscle oxidative capacity in humans: association with aerobic fitness
Authors: Austin Beever, Tom Tripp, Jenny Zhang, Martin MacInnis; Presenter: Austin Beever
Abstract: Oxidative capacity is the maximal rate at which skeletal muscle can utilize oxygen. While typically measured with skeletal muscle biopsy samples, muscle oxidative capacity can also be measured non-invasively with near-infrared spectroscopy (NIRS). The purpose of this study was to examine relationships between NIRS-derived muscle oxidative capacity and whole-body measures of aerobic fitness, specifically maximal oxygen uptake (VÌ‡O2max), lactate threshold (LT), and maximal fat oxidation (Fatmax). On two separate occasions, 22 participants (11 women and 11 men, 24.6+4.2 years, 67.8+9.8 kg, 172.2+9.1 cm) performed two sets of knee extension exercise (20 repetitions at 15% of maximum isokinetic voluntary torque), followed by a series of arterial occlusions to transiently halt blood flow and measure muscle deoxygenation. The change in muscle deoxygenation during recovery was fit with a monoexponential function to calculate NIRS-derived muscle oxidative capacity (i.e., tau, measured in seconds). Each session was proceeded by an incremental step test (25W/3min) or an incremental ramp test (30W/min) on a cycle ergometer to determine VÌ‡O2max, LT, and Fatmax. Data are presented as means (SD). On average, the NIRS-derived muscle oxidative capacity was 25.6 (7.9) s, VÌ‡O2max was 54.0 (5.4) ml/kg lean body mass/min, LT was 158 (57) W, and Fatmax was 0.44 (0.11) g/min. Though not associated with Fatmax (p=0.19, r=-0.28), NIRS-derived muscle oxidative capacity was negatively correlated with VÌ‡O2max (p<0.001, r=-0.72), and LT (p=0.03, r=-0.47). Thus, the NIRS-derived oxidative capacity appears to be physiologically relevant, making it a suitable measure for future exercise physiology research.
Title: Stress Response in Recreationally Active Female University Students
Authors: Crack, LE, Lebrun, C, Doyle-Baker, PK.; Presenter: Laura E. Crack
Abstract: Anovulatory cycles in female elite athletes are a common topic when discussing Relative Energy Deficiency in Sport (REDs). General stress, which likely plays an impactful role in REDs, are often measured by hormone levels. We prospectively observed stress in the CHESS (Changing Hormones with Exposure to Student Stress) study by measuring salivary cortisol, estrogen (E) and progesterone (P) levels in recreationally active female undergraduate students (n=19) with a mean (SD, ï‚±) age of 21.4 ï‚± 2.1 yrs. Cortisol was assessed by 4 samples: the cortisol awakening response (CAR) taken 30-minutes after waking and the diurnal response at 3 daily intervals. Activity level was determined by a Godin Leisure-Time Exercise Questionnaire score ≥ 24 (mean 66.05 ï‚± 20.44, range 34 – 110). Participants self-reported hormonal birth control use (HC, n=10) or not (NH, n=9). No baseline activity level differences were observed between HC vs NH (p=0.89), but the HCs were slightly older (p=0.01). E and P were collected at the mid-luteal phase of each menstrual cycle (day 21). Participants (94%) displayed a blunted CAR (< 14nmol) in one or more saliva collection(s) and 100% of the participants displayed P insufficiency (P: E Ratio <200). A blunted CAR response, although unexpected, may be associated with hypothalamic-pituitary axis dysregulation due to chronic stress or burnout. Chronic stress may be influencing P insufficiency leading to anovulatory cycles. Similarities, therefore, exist between female elite athletes and active students. The small sample is acknowledged and further research with more frequent testing of hormone levels is warranted.
Title: Non-Invasive Cardiac System (NICaS) derived resting and exercise-augmented hemodynamic parameters from patients with Fontan circulation
Authors: Pedram Hassan-Tash, Gurkirat Chana, David Kent, C. Nolan Turnbull, Meaghan Rempel, Nicole Johnston, Brett Hiebert, Robin Ducas, James Tam, Todd Duhamel, Ashish Shah; Presenter: Nolan Turnbull
Abstract: Introduction: Patients born with anatomical or functional single ventricle are palliated with establishment of Fontan circulation, characterized by passive filling of pulmonary circulation in absence of sub-pulmonary ventricle. Patients with Fontan circulation have limited exercise capacity; however, their resting and exercise-augmented hemodynamic parameters have not been well described. Non-Invasive Cardiac System (NICaS, NI Medical) provides hemodynamic measurements, using the whole body impedance cardiography. Methods: Twenty adult patients with Fontan circulation were assessed by cardiopulmonary exercise test (CPEx). Their resting & post-exercise hemodynamic parameters were measured using NICaS. Results: The average age of participants was 28±10. At rest the heart rate was 79±14 bpm that increased to 155±26 bpm with exercise. Their maximum oxygen represents 66±13% of maximum predicted for their age and sex. Resting SV was 50±16 ml that increased to 50±15 ml with exercise, however, due to increase in the heart rate with exercise, CI changed from 2.2±0.8 l/min/m2 at rest to 2.8±0.8 l/min/m2 post-exercise. Ten (50%) patients’ resting CI was in the range of CS. Cardiac power index (CPI) at rest was 0.41±0.16 w/m2 that increased to 0.58±0.2 w/m2 at the peak exercise. Resting total peripheral resistance index was 3512±1398 dn*s/cm5*m2 that reduced to 2851±1880 dn*s/cm5*m2 at the peak exercise. Conclusion: Patients with Fontan circulation have low cardiac output and reduced exercise capacity. This is the first study to report hemodynamics in the range of cardiogenic shock, among this cohort. Exercise-augmented CI was mainly due to increase in heart rate and reduction in total peripheral resistance. Further studies are required to improve hemodynamics and to evaluate their impact on overall outcomes.
Title: The Wellness App PILOT Study: Promoting Health Behavior Change
Authors: Nolan Turnbull, Roger Hamilton, Beverley Cassidy; Presenter: Nolan Turnbull
Abstract: There are many health apps, but few which have a cognitive-behavioral base to support long term health behavior change. The purpose of the study was to examine whether patients would engage with the Fountain of Health ‘Wellness App’ designed to track patient health behaviors in three active domains: physical activity, social connectedness and brain challenge. Twenty-three patients interested in making a health behavior change to promote brain health were recruited at a Nova Scotia primary care clinic. A health and resilience questionnaire on key self-rated areas of health behavior was given pre and post (after 4 weeks), and a SMART goal was invited and set in a key health behavior area and logged on the app. 21/23 patients successfully engaged with the app and were included in the study. Of these 21 patients, 18/21 (86%) reported the app was easy or very easy to use. Patients reported a relative increase in physical activity by 17% (p<0.05). The other four domains also increased over the four-week period: social connectedness (13%), brain challenge (5%), perception of self as aging successfully at this stage of life by (14%), and willingness to look after mental health (12%), but these changes were not significant. The current study found that the Fountain of Health Wellness app was an easy-to-use tool for patients, led to increases in self-reported physical activity, and may contribute positively to other health behavior change realms.