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
- Reviewed:
- 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.
Evidence of direct cardiac damage following high-intensity exercise in chronic energy restriction : A case report and literature review
- Authors: Baird, Marianne , Grace, Fergal , Sculthorpe, Nicholas , Graham, Scott , Fleming, Audrey , Baker, Julien
- Date: 2017
- Type: Text , Journal article
- Relation: Medicine Vol. 96, no. 27 (2017), p. 1-7
- Full Text:
- Reviewed:
- Description: Rationale: Following prolonged endurance events such as marathons, elevated levels of cardiospecific biomarkers are commonly reported. Although transiently raised levels are generally not considered to indicate clinical myocardial damage, comprehension of this phenomenon remains incomplete. The popularity of high-intensity interval training highlights a paucity of research measuring cardiac biomarker response to this type of exercise. This a posteriori case report discusses the elevation of cardiac troponins (cTn) associated with short interval, high-intensity exercise. Patient concerns: In this case report, an apparently healthy 29-year-old recreationally active female presented clinically raised cardiac troponin I (cTnI) levels (>0.04 ng/mL), after performing high-intensity cycle ergometer sprints. As creatine kinase (CK) is expressed by multiple organs (e.g., skeletal muscle, brain, and myocardium), cTnI assays were performed to determine any changes in total serum CK levels not originating from skeletal muscle damage. Diagnosis: A posteriori the individual's daily energy expenditure indicated chronically low-energy availability. Psychometric testing suggested that the individual scored positive for disordered eating, highly for fatigue levels, and low in mental health components. Outcomes: The current case report provides novel evidence of elevated cTnI occurring as a result of performing short duration, high intensity, cycle ergometer exercise in an individual with self-reported chronically depleted energy balance. A schematic to identify potentially “at risk” individuals is presented. Lessons: Considering this as a case report, results cannot be generalized; however, the main findings suggest that individuals who habitually restrict their calorie intake below their bodies’ daily energy requirements, may have elevated biomarkers of exercise induced myocardial stress from performing high-intensity exercise.
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:
Cardiac response to exercise in normal ageing : What can we learn from masters athletes?
- Authors: Beaumont, Alexander , Campbell, Amy , Grace, Fergal , Sculthorpe, Nicholas
- Date: 2018
- Type: Text , Journal article , Review
- Relation: Current Cardiology Reviews Vol. 14, no. 4 (2018), p. 245-253
- Full Text:
- Reviewed:
- Description: Background: Ageing is associated with an inexorable decline in cardiac and vascular function, resulting in an increased risk of Cardiovascular Disease (CVD). Lifestyle factors such as exercise have emerged as a primary therapeutic target in the prevention of CVD, yet older individuals are frequently reported as being the least active, with few meeting the recommended physical activity guidelines. In contrast, well trained older individuals (Masters athletes) have superior functional capacity than their sedentary peers and are often comparable with young non-athletes. Therefore, the 'masters' athlete may be viewed as a unique non-pharmacological model which may allow researchers to disentangle the inexorable from the preventable and the magnitude of the unavoidable 'true' reduction in cardiac function due to ageing. Conclusion: This review examines evidence from studies which have compared cardiac structure and function in well trained older athletes, with age-matched controls but otherwise healthy. © 2018 Bentham Science Publishers.
Sprint interval training and the school curriculum : Benefits upon cardiorespiratory fitness, physical activity profiles, and cardiometabolic risk profiles of healthy adolescents
- Authors: Martin-Smith, Rhona , Buchan, Duncan , Baker, Julien , Macdonald, Mhairi , Sculthorpe, Nicholas , Easton, Chris , Knox, Allan , Grace, Fergal
- Date: 2019
- Type: Text , Journal article
- Relation: Pediatric Exercise Science Vol. 31, no. 3 (2019), p. 296-305
- Full Text:
- Reviewed:
- Description: Background: This study examined the impact of a 4-week school-based sprint interval training program on cardiorespiratory fitness (CRF), daily physical activity (PA) behavior, and cardiometabolic risk (CMR) outcomes in adolescents. Methods: A total of 56 adolescents (22 females) were allocated to either an intervention (n = 22; 17.0 [0.3] y) or control group (n = 30; 16.8 [0.5] y). Intervention group performed 5 to 6, 30 second "all out" running sprints, interspersed with 30-second rest intervals, 3 times per week, for 4 consecutive weeks, whereas control group performed their normal physical education lessons. CRF was estimated from the 20-m multistage fitness test and PA behavior was determined using accelerometry. Fasting blood samples were obtained to measure biochemical markers of CMR. Results: Significant group x time interactions were observed for CRF (5.03 [1.66 to 8.40]; P < .001; d = 0.95), sedentary time (136.15 [91.91 to 180.39]; P = .004; d = 1.8), moderate PA (57.20 [32.17 to 82.23]; P < .001; d = 1.5), vigorous PA (5.40 [4.22 to 6.57]; P < .001; d = 1.2), fasting insulin (0.37 [-0.48 to 1.21]; P = .01; d = 1.0), homeostasis model of assessment-insulin resistance (0.26 [0.15 to 0.42]; P < .001; d = 0.9), and clustered CMR score (0.22 [-0.05 to 0.68]; P < .001; d = 10.63). Conclusion: Findings of this study indicate that 4 weeks of school-based sprint interval training improves CRF, improves PA profiles, and maintains CMR in adolescents during the school term.
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.
Six weeks of conditioning exercise increases total, but not free testosterone in lifelong sedentary aging men
- Authors: Hayes, Lawrence , Sculthorpe, Nicholas , Herbert, Peter , Baker, Julien , Spagna, Roberto , Grace, Fergal
- Date: 2015
- Type: Text , Journal article
- Relation: Aging Male Vol. 18, no. 3 (2015), p. 195-200
- Full Text:
- Reviewed:
- Description: INTRODUCTION: Advancing age is associated with a gradual decline in circulating androgens, and the putative role of exercise training on systemic androgens remains to be adequately defined. METHODS: The present investigation examined the impact of 6 weeks of supervised exercise training on resting levels of systemic hormones in a cohort of lifelong sedentary men [SED (n = 28), 62.5 +/- 5.3 years], compared with a positive control group of age-matched lifelong exercisers [LE (n = 20), 60.4 +/- 4.7 years, >30 years training history]. Blood hormones were sampled pre- and post-intervention from an antecubital forearm vein and analysed using electrochemiluminescent immunoassay. Cardiorespiratory fitness ([Formula: see text]) was determined via indirect calorimetry during an incremental cycle test to volitional exhaustion. RESULTS: Analysis of variance (ANOVA) revealed a lack of significant change in any parameter amongst LE, whilst SED experienced a significant exercise-induced improvement in cardiorespiratory fitness and total testosterone (all p < 0.05). Concurrent increases in sex hormone-binding globulin (SHBG; p < 0.05) resulted in a lack of change to either bioavailable or calculated free testosterone (p > 0.05) amongst SED. CONCLUSIONS: Although resting levels of systemic total testosterone increased in response to 6 weeks of exercise training, increases in SHBG negated any potential relationship between calculated-free or bioavailable testosterone. These findings indicate that increases in bioavailable testosterone fraction are not required for cardiorespiratory fitness improvements in aging men.
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.
The effects of a formal exercise training programme on salivary hormone concentrations and body composition in previously sedentary aging men
- Authors: Hayes, Lawrence , Grace, Fergal , Sculthorpe, Nicholas , Herbert, Peter , Ratcliffe, John , Kilduff, Liam , Baker, Julien
- Date: 2013
- Type: Text , Journal article
- Relation: SpringerPlus Vol. 2, no. 18 (2013), p. 1-5
- Full Text:
- Reviewed:
- Description: Alteration in body composition, physical function, and substrate metabolism occur with advancing age. These changes may be attenuated by exercise. This study examined whether twenty eight, previously sedentary males (62.5 +/- 5.3 years of age; body mass of 89.7 +/- 16.4 kg) adhering to the ACSM minimum guidelines for aerobic exercise for six weeks would improve exercise capabilities, body composition and salivary hormone profiles. After six weeks of adhering to the guidelines, salivary testosterone and vo(2max) (absolute and relative) increased (p < 0.05), whilst body fat percentage and body mass decreased (p < 0.05). Peak power output, fat free mass and cortisol values were not significantly different. Interestingly, salivary testosterone correlated inversely with body fat percentage (R(2) = .285, p = 0.011). These results suggest that despite previous inactivity, older males can achieve improvements in cardiorespiratory fitness, body composition and anabolism by adhering to simple lifestyle changes.
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.
Acute whole body UVA irradiation combined with nitrate ingestion enhances time trial performance in trained cyclists
- Authors: Muggeridge, David , Sculthorpe, Nicholas , Grace, Fergal , Willis, Gareth , Thornhill, Laurence , Weller, Richard , James, Philip , Easton, Chris
- Date: 2015
- Type: Text , Journal article
- Relation: Nitric Oxide : Biology and Chemistry Vol. 48, no. (2015), p. 3-9
- Full Text:
- Reviewed:
- Description: Dietary nitrate supplementation has been shown to increase nitric oxide (NO) metabolites, reduce blood pressure (BP) and enhance exercise performance. Acute exposure to ultraviolet (UV)-A light also increases NO bioavailability and reduces BP. We conducted a randomized, counterbalanced placebo-controlled trial to determine the effects of UV-A light alone and in combination with nitrate on the responses to sub-maximal steady-state exercise and time trial (TT) performance. Nine cyclists (VO2max 53.1 +/- 4.4 ml/kg/min) completed five performance trials comprising 10 min submaximal steady-state cycling followed by a 16.1 km TT. Following a familiarization the final four trials were preceded, in random order, by either (1) Nitrate gels (NIT) + UV-A, (2) Placebo (PLA) + UV-A, (3) NIT + Sham light (SHAM) and (4) PLA + SHAM (control). The NIT gels (2 x 60 ml gels, ~8.1 mmol nitrate) or a low-nitrate PLA were ingested 2.5 h prior to the trial. The light exposure consisted of 20 J/cm(2) whole body irradiation with either UV-A or SHAM light. Plasma nitrite was measured pre- and post-irradiation and VO2 was measured continuously during steady-state exercise. Plasma nitrite was higher for NIT + SHAM (geometric mean (95% CI), 332 (292-377) nM; P = 0.029) and NIT + UV-A (456 (312-666) nM; P = 0.014) compared to PLA + SHAM (215 (167-277) nM). Differences between PLA + SHAM and PLA + UV-A (282 (248-356) nM) were small and non-significant. During steady-state exercise VO2 was reduced following NIT + UVA (P = 0.034) and tended to be lower in NIT + SHAM (P = 0.086) but not PLA + UV-A (P = 0.381) compared to PLA + SHAM. Performance in the TT was significantly faster following NIT + UV-A (mean +/- SD 1447 +/- 41 s P = 0.005; d = 0.47), but not PLA + UV-A (1450 +/- 40 s; d = 0.41) or NIT + SHAM (1455 +/- 47 s; d = 0.28) compared to PLA + SHAM (1469 +/- 52 s). These findings demonstrate that exposure to UV-A light alone does not alter the physiological responses to exercise or improve performance in a laboratory setting. A combination of UV-A and NIT, however, does improve cycling TT performance in this environment, which may be due to a larger increase in NO availability.
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.
Aerobic training protects cardiac function during advancing age : A meta-analysis of four decades of controlled studies
- Authors: Beaumont, Alexander , Grace, Fergal , Richards, Joanna , Campbell, Amy , Sculthorpe, Nicholas
- Date: 2019
- Type: Text , Journal article , Review
- Relation: Sports Medicine Vol. 49, no. 2 (2019), p. 199-219
- Full Text:
- Reviewed:
- Description: Background: In contrast to younger athletes, there is comparatively less literature examining cardiac structure and function in older athletes. However, a progressive accumulation of studies during the past four decades offers a body of literature worthy of systematic scrutiny. Objectives: We conducted a systematic review, meta-analysis and meta-regression of controlled echocardiography studies comparing left ventricular (LV) structure and function in aerobically trained older athletes (> 45 years) with age-matched untrained controls, in addition to investigating the influence of chronological age. Methods: Electronic databases were searched from inception to January 2018 before conducting a random-effects meta-analysis to calculate pooled differences in means, effect size and 95% confidence intervals (CIs). Study heterogeneity was reported using Cochran’s Q and I2 statistic. Results: Overall, 32 studies (644 athletes; 582 controls) were included. Athletes had greater LV end-diastolic diameter (3.65 mm, 95% CI 2.66–4.64), interventricular septal thickness (1.23 mm, 95% CI 0.85–1.60), posterior wall thickness (1.20 mm, 95% CI 0.83–1.56), LV mass (72 g, 95% CI 46–98), LV mass index (28.17 g·m2, 95% CI 19.84–36.49) and stroke volume (13.59 mL, 95% CI 7.20–19.98) (all p < 0.01). Athletes had superior global diastolic function [ratio of early (E) to late (A) mitral inflow velocity (E/A) 0.18, 95% CI 0.13–0.24, p < 0.01; ratio of early (e′) to late (a′) diastolic annular tissue velocity (e′/a′) 0.23, 95% CI 0.06–0.40, p = 0.01], lower A (−8.20 cm·s−1, 95% CI −11.90 to −4.51, p < 0.01) and a′ (−0.72 cm·s−1, 95% CI −1.31 to −0.12, p = 0.02), and more rapid e′ (0.96 cm·s−1, 95% CI 0.05–1.86, p = 0.04). Meta-regression for chronological age identified that athlete–control differences, in the main, are maintained during advancing age. Conclusions: Athletic older men have larger cardiac dimensions and enjoy more favourable cardiac function than healthy, non-athletic counterparts. Notably, the athlete groups maintain these effects during chronological ageing. © 2018, The Author(s).
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.
High intensity interval training (HIIT) improves resting blood pressure, metabolic (MET) capacity and heart rate reserve without compromising resting myocardial function in sedentary aging men
- Authors: Grace, Fergal , Herbert, Peter , Elliott, Adrian , Beaumont, Alexander , Richards, Jo , Sculthorpe, Nicholas
- Date: 2017
- Type: Text , Journal article
- Relation: Experimental Gerontology Vol.109, no. (2018), p.75-81
- Full Text:
- Reviewed:
- Description: Background This study examined a programme of pre-conditioning exercise with subsequent high intensity interval training (HIIT) on blood pressure, echocardiography, cardiac strain mechanics and maximal metabolic (MET) capacity in sedentary (SED) aging men compared with age matched masters athletes (LEX). Methods Using a STROBE compliant observational design, 39 aging male participants (SED; n = 22, aged 62.7 ± 5.2 yrs) (LEX; n = 17, aged = 61.1 ± 5.4 yrs) were recruited to a study that necessitated three distinct assessment phases; enrolment (Phase A), following pre-conditioning exercise in SED (Phase B), then following 6 weeks of HIIT performed once every five days by both groups before reassessment (Phase C). Hemodynamic, echocardiographic and cardiac strain mechanics were obtained at rest and maximal cardiorespiratory and chronotropic responses were obtained at each measurement phase. Results The training intervention improved systolic, mean arterial blood pressure, rate pressure product and heart rate reserve (each P < 0.05) in SED and increased MET capacity in both SED and LEX (P < 0.01) which was amplified by HIIT. Echocardiography and cardiac strain measures were unremarkable apart from trivial increase to intra-ventricular septum diastole (IVSd) (P < 0.05) and decrease to left ventricular internal dimension diastole (LVId) (P < 0.05) in LEX following HIIT. Conclusions A programme of preconditioning exercise with HIIT induces clinically relevant improvements in blood pressure, rate pressure product and encourages recovery of heart rate reserve in SED, while improving maximal MET capacity in both SED and LEX without inducing any pathological cardiovascular remodeling. These data add to the emerging repute of HIIT as a safe and promising exercise prescription to improve cardiovascular function and metabolic capacity in sedentary aging.