• The Effect of Recommended Sharpening Characteristics on Skating Speed

      Cadeau, Luke; Applied Health Sciences Program
      The purpose of the study was to investigate the effect of combining recommended blade sharpening characteristics; namely, radius of contour, radius of hollow and pitch on skating speed in ice hockey players. An operational definition for recommended sharpening characteristics was derived from previous research, current industry practices and pilot work. Males, currently competing at the U16 (n = 21), U18 (n = 10), and Minor Midget AAA (n = 9) levels of competitive ice hockey were recruited to participate. Players completed a battery of eight on-ice skating drills representing skating skills typically used in game situations while skating on two blade sharpening conditions: (i) the player’s current sharpening characteristics and (ii) the recommended sharpening characteristics. Movement initiation time (T1; s) and total skating time (TT; s) were measured for each drill. Composite scores were calculated as the sum of times across seven of the eight drills for T1 (s) and TT (s). Two-tailed paired samples t-tests were conducted to determine if significant differences existed in T1 (s) and TT (s) between conditions. Significantly faster times were revealed for the recommended sharpening condition on 4 of the 8 measured T1’s (s/kg), on 2 of the 8 measured TT’s (s/kg), and on both composite T1 and TT scores (p < .05). Data was then grouped in three ways for further analysis; by the number of sharpening characteristics adjusted (1, 2, or 3), by position (forward & defense), and by player weight (≤81.6 kg & >81.6 kg). When grouped by the number of sharpening characteristics adjusted, results revealed no significant differences when one or all three characteristics were adjusted. When two characteristics were adjusted significant differences were observed in 2 of the 8 T1’s (s/kg) and TT’s (s/kg) and in composite T1 and TT scores. When results were grouped by position or player weight, mixed results were revealed; meaning significant differences were revealed only on select skating drills that varied by group. All significant differences revealed faster times for the recommended sharpening condition. The results revealed may be indicative of the complex relationship between sharpening characteristics and performance in various on-ice skating skills.
    • The Effect of Skate Blade Radius of Contour and Radius of Hollow on Skating Performance in Male Ice Hockey Players

      McKenzie, Andrew; Applied Health Sciences Program (Brock University, 2012-07-19)
      The primary purpose of this study was to investigate the effect of skate blade shape on skating performance. A secondary purpose was to evaluate if a change in hollow shape can create additional effects on skating performance. Thirty-seven male ice hockey players (age=18 years, SD=3.4) participated. The intervention consisted of four sharpening trials assessed using three on-ice tests. Participant feedback was also assessed using a Likert scale questionnaire. Statistical analysis included within-subject repeated measures MANOVA of trial by skating variables (p≤0.05). Results revealed Contour 1 enhanced performance compared to baseline on six variables at varsity level and five variables at midget level. Contour 1 enhanced performance compared to Contour 2 on six variables at the varsity and midget levels. Contour 1 also scored highest on the feedback questionnaire. Findings of this study indicate that contouring is a necessary practice to achieve optimal skating performance.
    • The Effect of Trainer Muscularity and Expertise on Self-Presentational Concerns, Body Image, and Performance in College Men during One-Repetition Maximum Testing

      Crozier, Scott; Applied Health Sciences Program (Brock University, 2012-09-18)
      This study attempted to manipulate self-presentational efficacy to examine the effect on social anxiety, social physique anxiety, drive for muscularity, and maximal strength performance during a one-repetition maximum (1-RM) chest press and leg press test. Ninety-nine college men with a minimum of six months of previous weight training experience were randomly assigned to complete a 1-RM protocol with either a muscular male trainer described as an expert or a lean male trainer described as a novice. Participants completed measures of self-presentation and body image prior to meeting their respective trainer, and following the completion of the 1-RM tests. Although the self-presentational efficacy manipulation was not successful, the trainers were perceived significantly differently on musculature and expertise. The group with the muscular, expert trainer reported higher social anxiety and attained higher 1-RM scores for the chest and leg press. Thus, trainer characteristics can affect strength performance and self-presentational concerns in this population.
    • The effectiveness of a health versus appearance message on pregnant women's intentions to exercise postpartum : the moderating role of self-monitoring

      Gaston, Anca.; Applied Health Sciences Program (Brock University, 2008-05-21)
      Despite the confimied health benefits of exercise during the postpartum period, many new mothers are not sufficiently active. The present research aimed to examine the effectiveness of 2 types of messages on intention to exercise after giving birth on 2 groups of pregnant women (low and high self-monitors) using the Theory of Planned Behavior as a theoretical basis. Participants were 2 1 8 pregnant women 1 8 years of age and older (Mean age = 27.9 years, SD = 5.47), and in their second or third trimester. Women completed a demographics questionnaire, a self-monitoring (SM) scale and the Godin Leisure Time Exercise Questionnaire for current and pre-pregnancy exercise levels. They then read one of two brochures, describing either the health or appearance benefits of exercise for postpartum women. Women's attitudes, social norms, perceived behavioral control, and intentions to exercise postpartum were then assessed to determine whether one type of message (health or appearance) was more effective for each group. A MANOVA found no significant effect (p>0.05) for message type, SM, or their interaction. Possible reasons include the fact that the two messages may have been too similar, reading any message about exercise may result in intentions to exercise, or lack of attention given to the brochure. Given the lack of research in this area, more studies are necessary to confirm the present results. Two additional exploratory analyses were conducted. Pearson correlations found higher levels of pre-pregnancy exercise and current exercise to be associated with more positive attitudes, more positive subjective norms, higher perceived behavioral control, and higher intention to exercise postpartum. A hierarchical regression was conducted to determine the predictive utility of attitudes, subjective norms, and perceived behavioral control on intention for each self-monitoring group. Results of the analysis demonstrated the three independent variables significantly predicted intention (p < .001) in both groups, accounting for 58-62% of the variance in intention. For low self-monitors, attitude was the strongest predictor of intention, followed by perceived behavioral control and subjective norm. For high self-monitors, perceived behavioral control was the strongest predictors, followed by attitudes and subjective norm. The present study has practical and real world implications by contributing to our understanding of what types of messages, in a brochure format, are most effective in changing pregnant women's attitudes, subjective norm, perceived behavioral control and intention to exercise postpartum and provides ftirther support for the use of the Theory of Planned Behavior with this population.
    • The Effectiveness of Infrastructure and Expertise on the Acquisition of Stickhandling and Puck Control Skills in Competitive Hockey Players

      Fickel, Jessica; Applied Health Sciences Program
      The purpose of the study was to compare the effectiveness of two sport-specific training methodologies using a novel stickhandling and puck control (SPC) training device; physical practice (PP), and physical practice and observational learning (PP+OL), on skill acquisition and retention of SPC skills in competitive hockey players. Male (N=40), atom-aged (2005/2006 birth years), hockey players were recruited to participate and assigned to one of three groups; PP (n=16), PP+OL (n=15) and control (n=9). All groups completed one 50-minute familiarization session and two assessment sessions [pre-training (Apre) and post-training (Apost)] consisting of off- and on-ice assessments. The PP group received eight, 50-minute on-ice SPC training sessions. The PP+OL group received the same on-ice training, plus an additional 10-minute observational learning session before each on-ice session. Only PP and PP+OL completed a retention assessment (Aret) following a two-week period of no training. The off-ice assessment consisted of height (cm), weight (kg) and a modified Aggiss and Walsh (1986) coordination assessment (# of successful repetitions). The on-ice assessment consisted of two forward skating drills measuring execution time (s) and five SPC drills, measuring interval time (s), execution time (s) and execution competency. Execution competency was assessed on a 12-point scale for each device within each SPC drill by an expert rater. Multiple two-way mixed analysis of variance (ANOVA) revealed no significant interactions between groups in execution time or competency on any of the five SPC drills, combined overall total time (COTT) or total competency (COTC). Significant main effects of training were revealed across the three assessments for execution time on 3/5 SPC drills and COTT, and execution competency on 1/5 SPC drills. A Bonferroni post hoc revealed execution time for Apost and Aret were significantly faster than Apre for 2/5 SPC drills and COTT, and execution time for Apost was significantly faster than Apre for 1/5 SPC drills (p≤.05). The control group revealed no significant differences between Apre and Apost for execution time or competency. In summary, eight, 50-minute on-ice SPC training sessions elicited an improvement in execution time while maintaining competency, however, the combination of PP+OL did not reveal further training benefits.
    • The effectiveness of interpretive methods in informal educational facilities : an experimental study with reference to marine parks

      Jiang, Yixing.; Applied Health Sciences Program (Brock University, 2006-05-21)
      Interpretation has been used in many tourism sectors as a technique in achieving building hannony between resources and human needs. The objectives of this study are to identify the types of the interpretive methods used, and to evaluate their effectiveness, in marine parks. This study reviews the design principles of an effective interpretation for marine wildlife tourism, and adopts Drams' five design principles (1997) into a conceptual framework. Enjoyment increase, knowledge gain, attitude and intention change, and behaviour modification were used as key indicators in the assessment of the interpretive effectiveness of the Vancouver Aquarium (VA) and Marineland Canada (MC). Since on-site research is unavailable, a virtual tour is created to represent the interpretive experiences in the two study sites. Self-administered questionnaires are used to measure responses. Through comparing responses to the questionnaires (pre-, post-virtual tours and follow-up), this study found that interpretation increased enjoyment and added to respondents' knowledge. Although the changes in attitudes and intentions are not significant, the findings indicate that attitude and intention changes did occur as a result of interpretation, but only to a limited extent. Overall results suggest that more techniques should be added to enhance the effectiveness of the interpretation in marine parks or self-guiding tours, and with careful design, virtual tours are the innovative interpretation techniques for marine parks or informal educational facilities.
    • The effects of a 12-week multifactorial exercise and balance training program on balance control in older adults

      Jehu, Deborah; Applied Health Sciences Program (Brock University, 2012-09-18)
      The current thesis investigated the effects of a 12-week multifactorial exercise and balance training program on balance control in older adults. Participants completed a baseline testing session which included a series of questionnaires, anthropometric measures, and 18 stance and walking tests. Those who were randomly assigned to the exercise group participated in the 12-week training program while the comparison group was asked not to change anything in his/her lifestyle during the 12-week control period, but were invited to participate in the training program after his/her control period. The same testing protocol was repeated after the 12-week period. The results indicated that there were improvements in the time to complete the walking tests but no change in trunk sway in both the exercise and comparison groups. No changes in stance durations or trunk sway were observed. The findings suggest that the current training program showed no significant improvement in balance control in healthy older adults.
    • The effects of a high fat diet on musculoskeletal health in aged male C57BL/6J mice

      Bott, Kirsten; Applied Health Sciences Program
      Aging and obesity are two major aspects that can negatively impact musculoskeletal structure and function. It is important to study these aspects because of current high rates of obesity and the increasing proportion of seniors in North America. This study investigated the effects of a long-term high fat and sucrose diet (HFS) superimposed with aging on bone and muscle structure and function. Male C57BL/6J mice were randomized 1 of 2 diets: control (AGE, AIN93M, 10.3% kcal fat, 100 g/kg sucrose) or HFS (HFS-AGE, 45.3% kcal fat 200 g/kg sucrose) for 13 weeks starting at 20 weeks of age to represent middle age. Trabecular bone structure and volumetric bone mineral density (vBMD), body composition, and grip strength were measured longitudinally at 20, 24, 28, and 32 weeks of age. In vitro contractile measures were performed on isolated soleus and extensor digitorum longus (EDL) muscles at baseline (BSL, 20 weeks of age, n=11) and at the end of the 13-week intervention when AGE (n=12) and HFS-AGE (n=12) mice were 33 weeks of age. Both the AGE and HFS-AGE groups had similar declines in trabecular bone (bone structure and vBMD). For muscle contractile function, HFS+AGE resulted in increased soleus cross-sectional area (CSA) compared AGE (p=0.0008), but this did not translate to greater twitch or tetanus peak force. The ratio of outcomes of bone to muscle declined in both the AGE and HFS-AGE groups as a result of a greater decline in key measures of bone structure (BV/TV) than muscle function (soleus and EDL peak tetanus and CSA) and was not altered by feeding HFS. In conclusion, beginning a HFS diet during middle age did not exacerbate age-related declines in bone or muscle, but these tissues do not decline in a coordinate manner with aging as bone structure declined at a greater rate than muscle function.
    • The Effects of a Menthol-Based Topical Analgesic on Delayed Onset Muscle Soreness-Induced Changes to Running Biomechanics and Pain Perception

      Gagnon, Ryan; Applied Health Sciences Program
      The purpose of this thesis was to evaluate the effects of a menthol-based topical analgesic on delayed onset muscle soreness (DOMS) induced changes to running biomechanics and pain perception in well-trained runners. A menthol-based topical analgesic (n=10) was compared against a placebo group (n=10) on measures of kinematics, spatio-temporal parameters, and the perception of pain. Three-Dimensional (3D) kinematics of the ankle, knee and hip as well as subjective pain (Comparative Pain Scale and Pressure Threshold) were measured during level treadmill running at baseline, 48 hours after a 30-minute DOMS-inducing downhill run, and after the application of a menthol analgesic. DOMS was induced from the downhill run as identified by our pain measures, however it had little effect on kinematic variables. Pressure threshold was significantly lower at both measurement sites for both groups and Comparative Pain Scale scores were significantly higher after inducing DOMS. There were significant interactions for condition x group, regardless of running speed; average knee and hip range of motion (ROM) during stance and swing were significantly different than baseline after inducing DOMS. The application of a menthol-based topical analgesic had no significant effect on kinematics or pain perception. Our well-trained participants may have been more well-adapted to manage DOMS-induced soreness while limiting changes to running biomechanics. Variability in gait mechanics may have also played a role in the unexpected changes between participants after inducing DOMS. Regardless of the effectiveness of the DOMS-inducing protocol, the menthol analgesic appeared to have no effect on kinematics or pain variables in well-trained runners. Key Words: Biomechanics, Gait, Menthol, Analgesic, Delayed Onset Muscle Soreness
    • The Effects of a Psychosocial Behavioural Intervention on Arterial Health in Children

      Johnson, Samantha C.; Applied Health Sciences Program (Brock University, 2013-10-11)
      This study evaluated the effects of a Leisure and Well-Being Model (LWM) psychosocial intervention on arterial health, measured by arterial stiffness and thickness, in 82 children aged 10-13 (n=41; intervention, n=41; control) over one year. The intervention was to provide children with the awareness, skill development, and application of positive emotion, personal strengths, coping, and free-time vitality. Results showed no change in arterial health for children exposed to the intervention compared to controls. However, a significant systolic blood pressure decrease was found in children exposed to the intervention and increased in those of the control group (F (1, 73) = 4.085, p = 0.047). This is the first study to show that a psychosocial intervention has a positive effect on childhood cardiovascular health within one year. Hence, if exposed for-or followed for- a longer period of time, it may be possible to see further improvements in arterial health.
    • The Effects of a Single Bout of Plyometric Exercise on Anabolic and Catabolic Osteokines in Girls and Adolescents

      Dekker, Jennifer; Applied Health Sciences Program
      It is well established that dynamic mechanical loading is both beneficial and necessary to the promotion and development of healthy bones. The aim of this study is to determine the response of osteokines related to the anabolic Wnt signalling pathway [sclerostin and dickkopf 1 (DKK-1)] and the catabolic RANKL pathway, [osteoprotogerin (OPG), receptor activator of nuclear factor kappa-β ligand (RANKL)], as well as the related transforming growth factors (TGF-β1, TGF-β2 and TGF-β3) to an acute bout of plyometric exercise in girls and adolescent females. Twenty six females, 14 girls (10.5 ± 0.4 years of age) and 12 adolescents (15.0 ± 0.3 years of age) were recruited to participate in this study. Serum samples were collected pre, 5 min post, 1 hour post and 24 h post exercise. Group differences were seen at baseline in DKK-1, TGF-β1, TGF-β2 and TGF-β3 with girls having significantly higher concentrations than the adolescents. A significant decrease was found after 24 hours in DKK-1. A significant decrease was also found in RANKL at 5 minutes post exercise that remained suppressed 1 hour and 24 hours following the cessation of the exercise protocol in both groups. Plyometric exercise was therefore successful in suppressing the catabolic osteokines DKK-1 and RANKL up to 24 hours following the cessation of exercise in girls and adolescent females.
    • The Effects of a Social-Evaluative Body Image Threat on Shame, Social Physique Anxiety, Body Dissatisfaction and Cortisol Responses in University Men

      Brianne, Ozimok; Applied Health Sciences Program (Brock University, 2014-10-30)
      Men struggle with body image concerns particularly related to the desire to be muscular. In women, social-evaluative body image threats have been linked to increased shame and cortisol responses, consistent with social self-preservation theory (SSPT), but no research has investigated these responses in men. Men (n = 66) were randomly assigned to either a social-evaluative threat (SET) or non-social-evaluative threat (N-SET) condition. Participants provided saliva samples and completed body shame, body dissatisfaction and social physique anxiety measures prior to and following their condition, during which anthropometric and strength measures were assessed. Results indicated men in the SET condition had higher body shame, social physique anxiety, and body dissatisfaction and had higher levels of cortisol than men in the N-SET condition post-social-evaluative threat. These findings, consistent with SSPT, suggest that social-evaluative body image threats may lead to increased body shame and social physique anxiety, greater body dissatisfaction and higher cortisol levels.
    • The Effects of Acute Aerobic Exercise on Inflammatory Markers and Mood in Individuals with Multiple Sclerosis and Spinal Cord Injury

      Donia, Scott; Applied Health Sciences Program
      The purpose of this study was to determine if acute exercise-induced reductions in pro-inflammatory cytokines contribute to exercise-induced improvements in mood in individuals with spinal cord injury (SCI) and multiple sclerosis (MS). Thirteen participants completed a single 30-minute bout of moderate-intensity exercise at 60% of their pre-determined VO2 peak. Mood was assessed before, immediately after, and one- hour post-exercise, via the Profile of Mood States Questionnaire (POMS). Blood samples were taken before, immediately after, and one-hour post exercise, and subsequently analyzed for serum pro-inflammatory cytokines (IL-6, IFN-γ, and TNF-α), as well as the amino acids tryptophan (TRP) and kynurenine (KYN). Previous work from our lab has shown that chronic reductions in pro-inflammatory cytokines via diet improve mood via the kynurenine pathway, which is integral in serotonin production. Following the bout of exercise, there was a significant improvement in mood as shown by a reduction in the total POMS questionnaire score from pre to post-exercise (32.5±25.8 to 22.4±21.9; p=0.025), as well as pre to one hour post-exercise (32.5±25.8 to 21.6±25.0; p=0.008). Subscale analysis showed significant reductions in the Tension, Depression and Anger components of the POMS from pre to post-exercise and from pre to one-hour post- exercise. Regarding pro-inflammatory cytokines, there were no exercise-induced changes in IL-6, but there was a significant main effect for time for TNF-α (with post-hoc analyses showing significant reductions from pre to one-hour post-exercise) and a trend for a main effect for time for IFN-γ (p=0.06). There were no changes in TRP, KYN or KYN/TRP. There were no correlations between changes in mood and changes in cytokines when all participants were analyzed. However, when considering only the participants that responded to exercise with an improved mood (n=7), there were significant correlations between exercise-induced changes in depression and exercise- induced changes in IL-6 (r=0.853; p=0.031) and a trend for a correlation with exercise- induced changes in TNF-α (r=0.722; p=0.067). These results suggest that exercise- induced changes in mood may be partially accounted for by exercise-induced changes in pro-inflammatory cytokines in individuals with SCI and MS, but not through a kynurenine pathway-dependent manner.
    • Effects of age on learning a spatial motor task in younger and older adults individualizing their knowledge of results schedule

      Carter, Michael J.; Applied Health Sciences Program (Brock University, 2011-01-25)
      Self-controlled KR practice has revealed that providing participants the opportunity to control their KR is superior for motor learning compared to participants replicating the KR schedule of a self-control participant, without the choice (e.g., yoked). The purpose of the present experiment was two-fold. First, to examine the utility of a self-controlled KR schedule for learning a spatial motor task in younger and older adults and second, to determine whether a self-controlled KR schedule facilitates an increased ability to estimate one’s performance in retention and transfer. Twenty younger adults and 20 older adults practiced in either the self-control or yoked condition and were required to push and release a slide along a confined pathway using their non-dominant hand to a target distance. The retention data revealed that as a function of age, a self-controlled KR schedule facilitated superior retention performance and performance estimations in younger adults compared to their yoked counterparts.
    • The effects of altered heat stress on voluntary pacing strategies during prolonged cycling

      Hartley, Geoffrey L.; Applied Health Sciences Program (Brock University, 2011-03-08)
      Central Governor Model (CGM) suggests that perturbations in the rate of heat storage (AS) are centrally integrated to regulate exercise intensity in a feed-forward fashion to prevent excessive thermal strain. We directly tested the CGM by manipulating ambient temperature (Tam) at 20-minute intervals from 20°C to 35°C, and returning to 20°C, while cycling at a set rate of perceived exertion (RPE). The synchronicity of power output (PO) with changes in HS and Tam were quantified using Auto-Regressive Integrated Moving Averages analysis. PO fluctuated irregularly but was not significantly correlated to changes in thermo physiological status. Repeated measures indicated no changes in lactate accumulation. In conclusion, real time dynamic sensation of Tam and integration of HS does not directly influence voluntary pacing strategies during sub-maximal cycling at a constant RPE while non-significant changes in blood lactate suggest an absence of peripheral fatigue.
    • The effects of an acute bout of whole-body vibration on pulse wave velocity in individuals with SCI

      Leber, Ben; Applied Health Sciences Program (Brock University, 2011-05-17)
      Cardiovascular disease is a leading cause of mortality in the spinal cord injured (SCI) population. Reduced arterial compliance is a cardiovascular risk factor and whole body vibration (WBV) has be en shown to improve arterial compliance in able-bodied individuals. The study investigated the effect of an acute session ofWBV on arterial compliance as measured by pulse wave velocity (PWV). On separate days, arm, leg and aortic PWV were measured pre- and post- a 45 minute session of passive stance (PS) and WBV. The WBV was intermittent with a set frequency of 45Hz and amplitude of O.6mm. There was no condition by time effect when comparing PWV after WBV and PS. Following WBV, aortic (928.6±127.7 vs. 901.1±96.6cm/sec), leg (1035.2±113.8 vs.l099.8±114.2cm/sec) and arm PWV (1118.9±119.8 vs. 1181.1±124.4cm/s) did not change. As such, WBV did not reduce arterial compliance, however future research with protocol modifications is recommended.
    • The effects of athletic scholarships on motivation in sport

      Medic, Nikola.; Applied Health Sciences Program (Brock University, 2003-07-14)
      The presence of rewards has been found to undermine intrinsic motivation (Deci & Ryan, 1999). This conclusion is primarily based on research conducted in non-sporting environments. The purpose of this study was to examine perceived motivational changes resulting from the hypothetical manipulation of a reward (i.e., athletic scholarships). Differences in "present" motivation between scholarship and non-scholarship athletes were also assessed. Gender, life roles, and sport experience were also examined in relation to scholarship status. Basketball players from four Ontario (n = 70) and seven U.S. Division I universities (n = 46) were examined. All athletes completed a set of demographic questions, as well as questions from the Sport Motivation Scale (SMS; Pelletier, Fortier, Vallerand, Tuson, Briere, & Blais, 1995) which assessed their "present" motivation. Athletes also completed the SMS to evaluate their "perceived future" motivation based on a hypothetical manipulation of the scholarship status. For Ontario non-scholarship athletes, extrinsic regulation (an extrinsic motive) increased with the introduction of a scholarship and the intrinsic motive to experience stimulation decreased. For U.S. scholarship athletes, the intrinsic motive to accomplish things decreased when scholarships were removed. When the two scholarship status groups were compared across "present" levels of motivation, U.S. scholarship males reported significantly higher levels of introjected regulation compared to Ontario non-scholarship males. Ontario non-scholarship females reported significantly higher levels of introjected regulation compared to U.S. scholarship females. U.S. scholarship athletes reported significantly higher levels of external regulation compared to Ontario non-scholarship athletes. Results offer partial support for self-determination theory. Implications for future research are discussed.
    • Effects of Cerebral Blood Flow and PETCO2 on Cognitive Function During Passive Heat Stress

      Watson, Cody Lang; Applied Health Sciences Program
      This thesis tested whether cognitive performance during passive heat stress may be affected by changes in cerebrovascular variables as opposed to strictly thermally-induced changes. A pharmacological reduction in cerebral blood flow (CBF) using indomethacin along with a hypocapnia-induced CBF reduction during passive heat stress (Tre ~1.5°C above baseline) were used to investigate any cerebrovascular-mediated changes in cognitive performance. Repeated measures analysis of variance indicated that One-Touch Stockings of Cambridge (OTS) performance was not affected by a significant reduction in CBF during passive heat stress. More specifically, OTS accuracy measures did not change as a result of either a reduction in CBF or increasing passive heat stress. However, it was found that OTS response time indices improved with increasing passive heat stress independent of CBF changes. In conclusion, a significant reduction in CBF does not cause additional changes in performance of an executive functioning task during severe passive heat stress.
    • Effects of Cerebral Blood Flow and Temperature on Executive Function During Moderate Hyperthermia

      Schultz Martins, Ricardo; Applied Health Sciences Program
      This thesis tested whether executive function using five different cognitive tests (Groton Maze Learning Test, 2-Back Test, Detection Test, Set Shifting and Groton Maze Learning Test recall) during passive heat stress may be affected by changes in cerebral blood flow (CBF) as opposed to thermal perception changes. An end-tidal forcing system was used to maintain eucapnia and baseline CBF in the isocapnic trial during the hypocapnia-induced CBF reduction. Repeated measures analysis of variance indicated that an increase of 5°C in mean skin temperature impaired working memory regardless of rectal temperature. The results also indicated that an increase of 1.5°C in rectal temperature increases the amount of errors by 38% when compared to baseline regardless of mean skin temperature. Although eucapnia was maintained during hyperthermia, it did not preserve baseline levels of mean middle cerebral artery velocity, indicating that changes in CBF are not the main hyperthermia-induced impairment factor for EF. In conclusion, increased skin temperature impaired working memory and increased rectal temperature impaired cognitive flexibility. In addition, as EF impairments were seen before any changes in CBF, it indicates that a decrease in CBF is not the main hyperthermia-induced impairment factor for EF.
    • The Effects of Chronic High Intensity Interval Training on Cardiometabolic Health in Individuals With Spinal Cord Injury

      Gibson, Mitchel; Applied Health Sciences Program
      Abstract Advancements in medicine and post-injury care has allowed for the extended life expectancy following spinal cord injuries (SCI). However, such advancements have led to a paradigm shift in the prevalence of secondary health complications from renal and pulmonary to cardiovascular and metabolic. In the able-bodied literature, accumulating evidence for high intensity interval training (HIIT) has shown that this time efficient, heart safe style of exercise may have advantages over moderate intensity continuous training (MICT) as a means to reduce cardiometabolic risk. The effectiveness of HIIT in an SCI population has yet to be explored. The current study examined the effectiveness of the “5 by 1” HIIT protocol over a 6-week timeframe, consisting of three supervised sessions per week in an SCI population. Outcome measures included VO2peak, cholesterol, triglycerides, waist circumference, blood pressure, pro an anti-inflammatory cytokine, and adipokines leptin and adiponectin. Results of the current study suggest that this protocol is an effective means to significantly improve aerobic fitness, however the intervention did induce significant metabolic change. Limitations such as small sample size (N=7) and the relatively short intervention duration may have limited these results. Further research focused on the effectiveness of HIIT in an SCI population is warranted to explore whether the metabolic benefit from HIIT may be dependent on a minimum baseline fitness level or power output that some individuals may not possess. In conclusion, the “5 by 1” HIIT protocol proved to be an effective means of improving aerobic capacity and therefore represents an alternative to the currently suggested MICT.