Observation of age-related decline in the performance of the transverse abdominis muscle
- Authors: Davies, Paul , Grace, Fergal , Lewis, Mark , Sculthorpe, Nicholas
- Date: 2016
- Type: Text , Journal article
- Relation: Physical Medicine and Rehabilitation Vol. 8, no. 1 (2016), p. 45-50
- Full Text: false
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- Description: BACKGROUND: Previous research has shown that the performance of skeletal muscle declines with advancing age. Coordination of the transverse abdominis (TrA), a deep postural muscle, has been shown to be reduced in persons with low back pain. No previous research has studied the effect of age on the activation on this muscle. OBJECTIVE: To assess the effect of age on TrA activation in response to rapid arm abduction. DESIGN: Cross-sectional cohort study. SETTING: University exercise physiology laboratory. PARTICIPANTS: A total of 18 adult men (aged 27 +/- 7.0 years) for the younger group and 11 older adults (5 men and 6 women, aged 59.6 +/- 4.0 years) were recruited for this study. METHOD: Participants were positioned on a treatment table and performed a series of rapid arm abduction movements with their right arm while the activation of the TrA muscle was recorded using ultrasound imaging. Onset of arm abduction was measured using surface electromyography and synchronized with the ultrasound through the ultrasound unit's electrocardiogram channel. The mean time difference between the 2 events was calculated during post-hoc analysis. MAIN OUTCOME MEASUREMENTS: A Mann-Whitney test was performed to test for differences in the onset performance of the TrA muscle between the 2 groups. RESULTS: Results showed that the older group was significantly slower than the younger group in engaging their TrA in response to the rapid arm abduction (P = .036). A separate analysis of the older group data showed that no significant differences existed between the male and female participants that could potentially have acted as a confounding factor for the main finding (P = .126). CONCLUSIONS: This study shows that older adults were slower than younger adults in activating their TrA muscle in response to rapid arm abduction. This delay has the potential to lead to increased occasions when the low back is unprotected, increasing the likelihood of injury or low back pain.
Cardiovascular risk and androgenic anabolic steroids
- Authors: Sculthorpe, Nicholas , Grace, Fergal , Angell, Peter , Baker, Julien , George, Keith
- Date: 2013
- Type: Text , Journal article
- Relation: British Journal of Cardiac Nursing Vol. 7, no. 6 (2013), p. 266-275
- Full Text: false
- Reviewed:
- Description: Although several drugs are purported to improve exercise performance, androgenic anabolic steroids (AAS) are the most widespread. Furthermore, unlike other drugs, their use has expanded beyond competition, to non-competitive and recreational athletes. Correspondingly health professionals are more likely to come into contact with users of AAS than with users of other performance-enhancing drugs. While there are numerous reports outlining serious cardiovascular consequences to high-dose AAS abuse, this evidence is often limited by difficulties in gaining access to users due to the legal status of AAS. Additionally the co-abuse of other substances (as additional muscle mass enhancers, or to mitigate possible side effects) is a further confounding factor. This review examines the evidence for AAS having a negative effect on the cardiac and vascular tissue and the corresponding risk of developing cardiovascular disease. Possible mechanisms of action by which AAS bring about these changes are also discussed.
Utility of the hypertriglyceridemic waist phenotype in the cardiometabolic risk assessment of youth stratified by body mass index
- Authors: Buchan, Duncan , Boddy, Lynne , Despres, Jean , Grace, Fergal , Sculthorpe, Nicholas , Mahoney, Craig , Baker, Julien
- Date: 2016
- Type: Text , Journal article
- Relation: Pediatric Obesity Vol. 11, no. 4 (2016), p. 292-298
- Full Text: false
- Reviewed:
- Description: BACKGROUND: It is unclear whether the hypertriglyceridemic waist phenotype (HTWP) can be used to identify those at most risk of cardiometabolic disorders. OBJECTIVES: The utility of the HTWP as a useful predictor of cardiometabolic risk in youth stratified by body mass index was assessed. METHODS: Three hundred and eighty-seven children (12-17.5 years) were used within this cross-sectional study. Participants were classified as normal weight or overweight/obese according to the International Obesity Task Force criteria. The HTWP phenotype was defined as having a waist circumference >/=90th percentile for age and gender with concomitant triglyceride concentrations >/=1.24 mmol L(-1) . Cardiometabolic risk profiles were compared using MANCOVA. RESULTS: Normal weight participants with the HTWP had significantly higher levels of C-reactive protein 2.6 +/- 0.4 vs. 1.6 +/- 0.3 mg L(-1) (P < 0.05) and cardiometabolic risk scores (1.3 +/- 0.3 vs. -0.7 +/- 0.2 and 2.1 +/- 0.4 vs. -0.5 +/- 0.2; both P < 0.05) compared with those of a normal weight without the HTWP. Overweight/obese participants with the HTWP had significantly higher C-reactive protein levels (3.5 +/- 0.6 vs. 2.6 +/- 0.5; P < 0.05) as well as both cardiometabolic risk scores (1.6 +/- 0.6 vs. 0.9 +/- 0.2 and 2.2 +/- 0.6 vs. 0.8 +/- 0.2; both P < 0.001) when compared with overweight/obese participants without the HTWP. CONCLUSIONS: The HTWP may serve as a simple and clinically useful approach to identify youth at increased cardiometabolic risk.
Commercial golf glove effects on golf performance and forearm muscle activity
- Authors: Sorbie, Graeme , Darroch, Paul , Grace, Fergal , Gu, Yaodong , Baker, Julien , Ugbolue, Ukadike
- Date: 2017
- Type: Text , Journal article
- Relation: Research in Sports Medicine Vol. 25, no. 4 (2017), p. 451-461
- Full Text: false
- Reviewed:
- Description: The study aimed to determine whether or not commercial golf gloves influence performance variables and forearm muscle activity during golf play. Fifteen golfers participated in the laboratory based study, each performing 8 golf swings with a Driver and 7-iron whilst wearing a glove and 8 without wearing the glove. Club head speed, ball speed and absolute carry distance performance variables were calculated. Surface electromyography was recorded from the flexor digitorum superficialis and extensor carpi radialis brevis on both forearm muscles. Club head speed, ball speed and absolute carry distance was significantly higher when using the Driver with the glove in comparison to the Driver without the glove (p < 0.05). No significant differences were evident when using the 7-iron and no significant differences were displayed in muscle activity in either of the conditions. Findings from this study suggest that driving performance is improved when wearing a glove.
Telomeres, exercise and cardiovascular disease : Finding the means to justify the ends
- Authors: Chilton, Warrick , O'Brien, Brendan , Grace, Fergal , Charchar, Fadi
- Date: 2017
- Type: Text , Journal article
- Relation: Acta Physiologica Vol. 220, no. 2 (2017), p. 186-188
- Full Text: false
- Reviewed:
Left ventricular speckle tracking-derived cardiac strain and cardiac twist mechanics in athletes : A systematic review and meta-analysis of controlled studies
- Authors: Beaumont, Alexander , Grace, Fergal , Richards, Joanna , Hough, John , Oxborough, David , Sculthorpe, Nicholas
- Date: 2017
- Type: Text , Journal article
- Relation: Sports Medicine Vol. 47, no. 6 (2017), p. 1145-1170
- Full Text: false
- Reviewed:
Exercise-induced responses in salivary testosterone, cortisol, and their ratios in men : A meta-analysis
- Authors: Hayes, Lawrence , Grace, Fergal , Baker, Julien , Sculthorpe, Nicholas
- Date: 2015
- Type: Text , Journal article
- Relation: Sports Medicine Vol. 45, no. 5 (2015), p. 713-726
- Full Text: false
- Reviewed:
- Description: BACKGROUND: Testosterone, cortisol and their ratios may be indicators of anabolic status, but technical issues surrounding blood sampling has limited wider application. The advent of salivary testosterone (sal-T) analysis simplified sample acquisition, resulting in a subsequent rapid increase in the number of published research articles. OBJECTIVE: The objective of this study was to undertake a meta-analysis to determine the effect of acute exercise bouts on post exercise sal-T and salivary cortisol (sal-C) concentrations and their ratio (sal-T:C). DATA SOURCES: Relevant databases such as PubMed, Web of Science, Science Direct and SPORTDiscus were searched up to and including 31 December 2013 for the term 'saliva AND testosterone AND exercise'. STUDY SELECTION: Studies (n = 21) selected from the 933 identified included randomised controlled trials (RCTs; n = 2), uncontrolled trials (UCTs; n = 18) and control trials (CTs; n = 1), all of which had an exercise component characterised as either aerobic, resistance or power training, each with acute sal-T and sal-C measurement obtained within 30 min of exercise bout completion. STUDY APPRAISAL AND SYNTHESIS METHODS: A meta-analysis was conducted on change in sal-T, sal-C and the sal-T:C ratio following exercise using standard difference in means (SDM) and a random effects model. RESULTS: For aerobic, resistance and power exercise, the overall SDMs for sal-T were 0.891, 1.061 and 0.509, respectively; for sal-C, the SDMs were 3.041, 0.773 and 1.200, respectively. For sal-T:C, the SDMs were -2.014, 0.027 and -0.968, respectively. RCTs, UCTs and CTs were separated by subgroup analysis. There were significant differences in overall weighted SDM values for sal-T between RCTs, UCTs and CTs within exercise modes. When examining aerobic exercise interventions, a quantitative interaction of study design was observed. RCTs resulted in a greater SDM than UCTs (1.337 vs. 0.446). Power interventions displayed a qualitative interaction with study design. UCTs where baseline measures were obtained 24 h before exercise had an SDM of -1.128, whereas UCTs where baseline was determined immediately prior to exercise had an SDM of 0.486. The single CT trial had an SDM of 2.260. Resistance exercise interventions were primarily UCTs; however, an observed influence of baseline sampling time whereby immediately pre- and 24 h pre-exercise resulted in differing SDMs. The sole resistance exercise RCTs resulted in the greatest SDM (2.500). CONCLUSION: The current body of evidence regarding acute responses of sal-T to exercise is weak. This meta-analysis identifies varying exercise-dependent effect sizes. Each appear to be greatly influenced by study design and sample timing. There is a need for more RCTs and a standardised methodology for the measurement of salivary hormones in order to better determine the effect of exercise modality.
Androgens affect myogenesis in vitro and increase local IGF-1 expression
- Authors: Sculthorpe, Nicholas , Solomon, Andrew M , Sinanan, Andrea C M , Bouloux, Pierre-Marc G , Grace, Fergal , Lewis, Mark
- Date: 2012
- Type: Text , Journal article
- Relation: Medicine and Science in Sports and Exercise Vol. 44, no. 4 (2012), p. 610-615
- Full Text: false
- Reviewed:
- Description: PURPOSE: The mechanism whereby anabolic androgens are associated with hypertrophy of skeletal muscle is incompletely understood but may involve an interaction with locally generated insulin-like growth factor (IGF) 1. The present investigation utilized a cell culture model of human skeletal muscle-derived cell maturation to test the hypothesis that androgens increase differentiation of human muscle precursor cells in vitro and to assess effects of androgen with or without IGF-1 on IGF-1 messenger RNA (mRNA) expression in human muscle precursor cells. METHODS: Differentiation of muscle-derived cells was induced under standard low-serum conditions. Cultures were then exposed to androgen (testosterone (T)) at 50, 100, and 500 nM or IGF-1 (10-50 ng.mL(-)(1)). Immunocytochemistry and real-time polymerase chain reaction (RT-PCR) were used to assess effects of androgens and IGF-1 after 3- (early) or 7-d (late) muscle differentiation, respectively; RT-PCR was used to quantify the effects on androgen receptor expression. RESULTS: Under low-serum conditions, 3-d exposure to androgens or IGF-1 or both resulted in no significant increase in cellular myogenic commitment. After 7-d exposure, however, T and IGF-1 were both found to increase fusion index with no observable synergistic effect. T also increased IGF-1 mRNA generation (P < 0.0001), whereas exogenous IGF-1 (P < 0.001) reduced IGF-1 mRNA transcription relative to control. The T effect was reversible after treatment with flutamide, an androgen receptor antagonist. CONCLUSIONS: Both T and IGF-1 increase myogenic commitment after 7-d exposure to a differentiation medium. With T causing a concomitant increase in IGF-1 mRNA underpinning IGF-1 as a central mediator in the cellular pathways associated with muscle hypertrophy, including those affected by androgens. The novel system described has the potential for elucidating the pattern of growth factor effects associated with androgens in skeletal muscle.
Electromyographic analyses of the erector spinae muscles during golf swings using four different clubs
- Authors: Sorbie, Graeme , Grace, Fergal , Gu, Yaodong , Baker, Julien , Ugbolue, Ukadike
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of Sports Sciences Vol. 36, no. 7 (2017), p. 717-723
- Full Text: false
- Reviewed:
- Description: The purpose of this study was to compare the electromyography (EMG) patterns of the thoracic andlumbar regions of the erector spinae (ES) muscle during the golf swing whilst using four different golfclubs. Fifteen right-handed male golfers performed a total of twenty swings in random order using thedriver, 4-iron, 7-iron and pitching-wedge. Surface EMG was recorded from the lead and trail sides of thethoracic and lumbar regions of the ES muscle (T8, L1 and L5 lateral to the spinous-process). Three-dimensional high-speed video analysis was used to identify the backswing, forward swing, acceleration,early and late follow-through phases of the golf swing. No significant differences in muscle-activationlevels from the lead and trail sides of the thoracic and lumbar regions of the ES muscle were displayedbetween the driver, 4-iron, 7-iron and pitching-wedge (P > 0.05). The highest mean thoracic and lumbarES muscle-activation levels were displayed in the forward swing (67–99% MVC) and acceleration (83–106% MVC) phases of the swing for all clubs tested. The findings from this study show that there wereno significant statistical differences between the driver, 4-iron, 7-iron and pitching-wedge whenexamining muscle activity from the thoracic and lumbar regions of the ES muscle.
Prolonged androgenic anabolic steroid (AAS) induced QT interval shortening : A suitable screening tool?
- Authors: Sculthorpe, Nicholas , Taylor, Lee , Grace, Fergal
- Date: 2016
- Type: Text , Journal article
- Relation: Drug Testing and Analysis Vol. 8, no. 1 (2016), p. 120-122
- Full Text: false
- Reviewed:
- Description: Androgenic anabolic steroid (AAS) abuse is associated with changes in cardiac electrophysiology. Recently heart rate corrected QT interval (QTc) has been suggested as a method of screening for AAS use in athletes despite conflicting reports. This study aimed to further investigate the effect of AAS on QTc in a cohort of long-term AAS users in whom the affects may be more pronounced. Using a cross-sectional cohort design with AAS using resistance trained athletes (AS n = 15) and a group of non-AAS using resistance trained, age matched controls (C n = 15). AS had a long history of AAS use (18 +/- 2 yrs) and AS and C both had >19 years of resistance training. Participants underwent a resting electrocardiogram (ECG), from which, the QTc interval was calculated using the Bazett formula. The main outcome measure was significant differences in mean corrected QTc between groups. A secondary outcome was to calculate a QTc that best differentiated between C and AS. Results indicated that QTc was shorter in AS than in C (382.0 +/- 21.01 ms versus 409 +/- 18.77 ms for AS and C respectively p < 0.001). Chi squared analyses revealed a greater incidence of QTc < 380 ms in AS versus C p < 0.01, specificity 93% sensitivity 60%). In conclusion these results supports previous findings that AAS use causes a reduction in QTc, however, the specificity and sensitivity in our sample is lower than reported previously and precludes use as a screening tool.
Impact of low-volume, high-intensity interval training on maximal aerobic capacity, health-related quality of life and motivation to exercise in ageing men
- Authors: Knowles, Ann-Marie , Herbert, Peter , Easton, Chris , Sculthorpe, Nicholas , Grace, Fergal
- Date: 2015
- Type: Text , Journal article
- Relation: Age Vol. 37, no. 2 (2015), p. 25
- Full Text: false
- Reviewed:
- Description: There is a demand for effective training methods that encourage exercise adherence during advancing age, particularly in sedentary populations. This study examined the effects of high-intensity interval training (HIIT) exercise on health-related quality of life (HRQL), aerobic fitness and motivation to exercise in ageing men. Participants consisted of males who were either lifelong sedentary (SED; N = 25; age 63 +/- 5 years) or lifelong exercisers (LEX; N = 19; aged 61 +/- 5 years). [Formula: see text] and HRQL were measured at three phases: baseline (Phase A), week seven (Phase B) and week 13 (Phase C). Motivation to exercise was measured at baseline and week 13. [Formula: see text] was significantly higher in LEX (39.2 +/- 5.6 ml kg min(-1)) compared to SED (27.2 +/- 5.2 ml kg min(-1)) and increased in both groups from Phase A to C (SED 4.6 +/- 3.2 ml kg min(-1), 95 % CI 3.1 - 6.0; LEX 4.9 +/- 3.4 ml kg min(-1), 95 % CI 3.1-6.6) Physical functioning (97 +/- 4 LEX; 93 +/- 7 SED) and general health (70 +/- 11 LEX; 78 +/- 11 SED) were significantly higher in LEX but increased only in the SED group from Phase A to C (physical functioning 17 +/- 18, 95 % CI 9-26, general health 14 +/- 14, 95 % CI 8-21). Exercise motives related to social recognition (2.4 +/- 1.2 LEX; 1.5 +/- 1.0 SED), affiliation (2.7 +/- 1.0 LEX; 1.6 +/- 1.2 SED) and competition (3.3 +/- 1.3 LEX; 2.2 +/- 1.1) were significantly higher in LEX yet weight management motives were significantly higher in SED (2.9 +/- 1.1 LEX; 4.3 +/- 0.5 SED). The study provides preliminary evidence that low-volume HIIT increases perceptions of HRQL, exercise motives and aerobic capacity in older adults, to varying degrees, in both SED and LEX groups.
Utility of three anthropometric indices in assessing the cardiometabolic risk profile in children
- Authors: Buchan, Duncan , Boddy, Lynne , Grace, Fergal , Brown, Elise , Sculthorpe, Nicholas , Cunningham, Conor , Murphy, Marie , Dagger, Rebecca , Foweather, Lawrence , Graves, Lee , Hopkins, Nicola , Stratton, Gareth , Baker, Julien
- Date: 2016
- Type: Text , Journal article
- Relation: American Journal of Human Biology Vol. , no. (2016), p. 1-10
- Full Text: false
- Reviewed:
- Description: OBJECTIVES: To evaluate the ability of BMI, WC, and WHtR to identify increased cardiometabolic risk in pre-adolescents. METHODS: This is a cross-sectional study involving 192 children (10.92 +/- 0.58 years, 56% female) from the United Kingdom between 2010 and 2013. Receiver operating characteristic curves determined the discriminatory ability of BMI, WC and WHtR to identify individuals with increased cardiometabolic risk (increased clustered triglycerides, HDL-cholesterol, systolic blood pressure, cardiorespiratory fitness, and glucose). RESULTS: A WHtR >/= 0.5 increased the odds by 5.2 (95% confidence interval 2.6 - 10.3) of having increased cardiometabolic risk. Similar associations were observed for BMI and WC. Both BMI-z and WHtR were fair predictors of increased cardiometabolic risk, although BMI-z demonstrated the best trade-off between sensitivity and specificity, 76.1% and 63.6%, compared with 68.1% and 65.5% for WHtR. Cross-validation analysis revealed that BMI-z and WHtR correctly classified 84% of individuals (kappa score = 0.671, 95% CI 0.55, 0.79). The sensitivity of the cut-points suggests that 89.3% of individuals were correctly classified as being at risk with only 10.7% misdiagnosed whereas the specificity of the cut-points indicated that 77.8% of individuals were correctly identified as being healthy with 22.2% of individuals incorrectly diagnosed as being at risk. CONCLUSIONS: Findings suggest that WHtR provides similar cardiometabolic risk estimates to age and sex adjusted BMI.
Evidence of altered cardiac electrophysiology following prolonged androgenic anabolic steroid use
- Authors: Sculthorpe, Nicholas , Grace, Fergal , Jones, Peter , Davies, Bruce
- Date: 2010
- Type: Text , Journal article
- Relation: Cardiovascular Toxicology Vol. 10, no. 4 (2010), p. 239-243
- Full Text: false
- Reviewed:
- Description: The non-therapeutic use of androgenic anabolic steroids (AAS) is associated with sudden cardiac death. Despite this, there is no proposed mechanism by which this may occur. Signal-averaged ECG (SAECG) allows the assessment of cardiac electrical stability, reductions of which are a known risk factor for cardiac arrhythmias. The aim of the present study was to examine cardiac electrical stability using SAECG in a group (n = 15) of long-term AAS users (AAS use 21.3 +/- 3.1 years) compared with a group (n = 15) of age-matched weight lifters (WL) and age-matched sedentary controls [C (n = 15)]. AS, WL and C underwent SAECG analysis at rest and following an acute bout of exercise to volitional exhaustion. SAECGs were analyzed using a 40 Hz filter and were averaged over 200 beats. Results indicate a non-significant trend for increased incidence of abnormal SAECG measures at rest in AS (P = 0.55). However, AS demonstrated a significantly higher incidence of abnormalities of SAECG following exercise than C or WL (P < 0.05). In conclusion, the higher incidence of abnormal SAECG measurements immediately post-exercise in the AAS group places them at a greater risk of sudden death. The present study provides a strong contraindication to the use of AAS.
Resting steroid hormone concentrations in lifetime exercisers and lifetime sedentary males
- Authors: Hayes, Lawrence , Sculthorpe, Nicholas , Herbert, Peter , Baker, Julien , Hullin, David , Kilduff, Liam , Grace, Fergal
- Date: 2015
- Type: Text , Journal article
- Relation: Aging Male Vol. 18, no. 1 (2015), p. 22-26
- Full Text: false
- Reviewed:
- Description: INTRODUCTION: Advancing age in men is associated with a progressive decline in serum testosterone (T) and interactions between exercise, aging and androgen status are poorly understood. The primary aim of this study was to establish the influence of lifelong training history on serum T, cortisol (C) and sex hormone binding globulin (SHBG) in aging men. A secondary aim was to determine the agreement between serum and salivary measurement of steroid hormones in ageing men. METHODS: Serum and salivary steroid hormones (serum C, T and SHBG, and salivary measures of C and T) were determined and compared between two distinct groups; lifelong exercising males (LE [n = 20], 60.4 +/- 4.7 year) and age matched lifelong sedentary individuals (SED [n = 28], 62.5 +/- 5.3 years). RESULTS: T-test revealed a lack of significant differences for serum C or SHBG between LE and SED, while Mann-Whitney U revealed a lack of differences in total T (TT), bioavailable T (bio-T) or free testosterone (free-T). Further, salivary T (sal-T) did not correlate with serum markers of T in LE, SED, or when pooled (r = 0.040; p > 0.05). CONCLUSIONS: Findings from this investigation suggested that resting levels of serum T and calculated free-T was unable to distinguish between diverse lifelong training histories in aging men. Further, sal-T was not an appropriate indicator of serum T and calculated free-T values in older males and considerable caution should be exercised when interpreting sal-T measurements in aging males.
Strength adaptation to squat exercise is different between Caucasian and South Asian novice exercisers
- Authors: Knox, Allan , Sculthorpe, Nicholas , Baker, Julien , Grace, Fergal
- Date: 2017
- Type: Text , Journal article
- Relation: Research in Sports Medicine Vol. 25, no. 3 (2017), p. 373-383
- Full Text: false
- Reviewed:
- Description: This study compared the progression of muscular strength (MS) adaptation between age-matched Caucasian (CAUC) and South Asian (SOU) men during 6 weeks (3x week-1) of resistance training. MS was determined pre and post intervention by 3-repetition maximum (3RM) strength tests, and data were analysed using repeated measures ANOVA. Pre-intervention upper and lower body 3RM were similar between groups and both upper and lower body 3RM increased in CAUCs (P < .001) and SOUs (P < .001) following resistance training. However, lower body strength adaptation (3RM) was higher in CAUCs compared with SOUs (P = .002). There was a significant group x time interaction in strength progression of the squat exercise (P = 0.03) from session 7 through to 18 (completion). The present study offers novel but provisional data that lower body strength adaptation is slower in SOU than CAUC men despite comparable adaptation to upper body strength.
Perspectives on Anabolic Androgenic Steroids (AAS) and doping in sport and health
- Authors: Grace, Fergal , Baker, Julien
- Date: 2012
- Type: Text , Edited book
- Full Text: false
An examination of exercise mode on ventilatory patterns during incremental exercise
- Authors: Elliott, Adrian , Grace, Fergal
- Date: 2010
- Type: Text , Journal article
- Relation: European Journal of Applied Physiology Vol. 110, no. 3 (2010), p. 557-562
- Full Text: false
- Reviewed:
- Description: Both cycle ergometry and treadmill exercise are commonly employed to examine the cardiopulmonary system under conditions of precisely controlled metabolic stress. Although both forms of exercise are effective in elucidating a maximal stress response, it is unclear whether breathing strategies or ventilator efficiency differences exist between exercise modes. The present study examines breathing strategies, ventilatory efficiency and ventilatory capacity during both incremental cycling and treadmill exercise to volitional exhaustion. Subjects (n = 9) underwent standard spirometric assessment followed by maximal cardiopulmonary exercise testing utilising cycle ergometry and treadmill exercise using a randomised cross-over design. Respiratory gases and volumes were recorded continuously using an online gas analysis system. Cycling exercise utilised a greater portion of ventilatory capacity and higher tidal volume at comparable levels of ventilation. In addition, there was an increased mean inspiratory flow rate at all levels of ventilation during cycle exercise, in the absence of any difference in inspiratory timing. Exercising V(E)/VCO(2)slope and the lowest V(E)/VCO(2)value, was lower during cycling exercise than during the treadmill protocol indicating greater ventilatory efficiency. The present study identifies differing breathing strategies employed during cycling and treadmill exercise in young, trained individuals. Exercise mode should be accounted for when assessing breathing patterns and/or ventilatory efficiency during incremental exercise.
Exercise
- Authors: Grace, Fergal , Baker, Julien
- Date: 2012
- Type: Text , Book chapter
- Relation: Perinatal mental health - A Clinical guide Part 6. Chapter 31 p. 389-401
- Full Text: false
- Reviewed:
- Description: Health pregnant women are encouraged to partake in exercise, which is increasingly being shown to to be beneficial for both the mother and child (Davies et al., 2003; Dempsey et al., 2005). While exercise training during pregnancy is common practice among a subgroup of physically active women, pregnancy and postpartum studies reveal there is generally a high risk for inactivity among pregnant womwn, with signficant reductions in previously established levels of activity (Albright and Maddock, 2006; Downs and Hausenbals, 2004; Zhang and Savitz, 1996
A commentary on "Testosterone and cortisol jointly modulate risk-taking" by P.H. Mehta, K.M. Welker, S. Zilioli, J.M. Carre, Psychoneuroendocrinology, 2015, 56, 88-99
- Authors: Hayes, Lawrence , Sculthorpe, Nicholas , Grace, Fergal
- Date: 2016
- Type: Text , Journal article
- Relation: Psychoneuroendocrinology Vol. 63, no. (2016), p. 380-381
- Full Text: false
- Reviewed:
Comparison of thoracic and lumbar erector spinae muscle activation before and after a golf practice session
- Authors: Sorbie, Graeme , Grace, Fergal , Gu, Yaodong , Baker, Julien , Ugbolue, Ukadike
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of Applied Biomechanics Vol. 33, no. 4 (2017), p. 288-293
- Full Text: false
- Reviewed:
- Description: Lower back pain is commonly associated with golfers. The study aimed: to determine whether thoracic- and lumbar-erector-spinae muscle display signs of muscular fatigue after completing a golf practice session, and to examine the effect of the completed practice session on club head speed, ball speed and absolute carry distance performance variables. Fourteen right-handed male golfers participated in the laboratory-based-study. Surface electromyography (EMG) data was collected from the lead and trail sides of the thoracic- and lumbar-erector-spinae muscle. Normalized root mean squared (RMS) EMG activation levels and performance variables for the golf swings were compared before and after the session. Fatigue was assessed using median frequency (MDF) and RMS during the maximum voluntary contraction (MVC) performed before and after the session. No significant differences were observed in RMS thoracic- and lumbar-erector-spinae muscle activation levels during the five phases of the golf swing and performance variables before and after the session (p > .05). Significant changes were displayed in MDF and RMS in the lead lower lumbar and all trail regions of the erector-spinae muscle when comparing the MVC performed before and after the session (p < .05). Fatigue was evident in the trail side of the erector-spinae muscle after the session.