An evaluation of temporal and club angle parameters during golf swings using low cost video analyses packages.

The purpose of this study was to compare swing time and golf club angle parameters during golf swings using three, two dimensional (2D) low cost, Augmented-Video-based-Portable-Systems (AVPS) (Kinovea, SiliconCoach Pro, SiliconCoach Live). Twelve right-handed golfers performed three golf swings whilst being recorded by a high-speed 2D video camera. Footage was then analysed using AVPS-software and the results compared using both descriptive and inferential statistics. There were no significant differences for swing time and the golf phase measurements between the 2D and 3D software comparisons. In general, the results showed a high Intra class Correlation Coefficient (ICC > 0.929) and Cronbach's Coefficient Alpha (CCA > 0.924) reliability for both the kinematic and temporal parameters. The inter-rater reliability test for the swing time and kinematic golf phase measurements on average were strong. Irrespective of the AVPS software investigated, the cost effective AVPS can produce reliable output measures that benefit golf analyses.

An electromyographic assessment pilot study on the reliability of the forearm muscles during multi-planar maximum voluntary contraction grip and wrist articulation in young males.

BACKGROUND: Electromyographic systems are widely used in scientific and clinical practice. The reproducibility and reliability of these measures are crucial when conducting scientific research and collecting experimental data. OBJECTIVE: To test the reliability of surface electromyography signals from both the Flexor Digitorum Superficialis (FDS) and Extensor Carpi Radialis Brevis (ECRB) muscles of both the left and right arms during an individual, static multi-planar maximum voluntary contraction handgrip task using the Myon 320 system (Myon AG, Switzerland). METHODS: Eight right-handed male participants performed two maximal handgrip tests in five separate wrist positions using both hands. Muscle activity was recorded from both forearms. Reliability was measured using the Standard Error of Measurement (SEM), Coefficient of Variation (CV) and Intra-class correlation coefficients. Wrist joint position correlations within and between the FDS and ECRB muscle activities were also analysed. RESULTS: Absolute reliability was shown across all positions for both hands with CV and SEM recorded at below 10%. The output measures indicate that the Myon 320 system (Myon AG, Switzerland) produces good to fair reliability when assessing forearm muscle activity. Correlations in the left FDS muscles were negative. Correlations between the left ECRB and left FDS muscles were variable but positive between the right ECRB and right FDS muscles. CONCLUSIONS: The data sets retrieved from all participants were reliably evaluated. Wrist position correlations within and between the FDS and ECRB muscles may have been influenced by hand dominance. The findings demonstrate that the methods and systems outlined in this study can be used reliably in future research.

Short-Term and Lifelong Exercise Training Lowers Inflammatory Mediators in Older Men.

Increased basal low-grade inflammation is observed with advancing age, which is augmented by physical inactivity. However, data regarding the influence of lifelong exercise training and particularly high-intensity interval training (HIIT) on inflammatory mediators in older men are scarce. Therefore, we examined effects of 6weeks of aerobic preconditioning followed by 6weeks of HIIT on inflammatory mediators [interleukin (IL)-6, homocysteine, and high-sensitivity C-reactive protein (hsCRP)] in previously sedentary older men (SED) and masters athletes (LEX). Further, we investigated whether SED exhibited greater basal inflammatory biomarkers compared to LEX. Twenty-two men (aged 62±2years) participated in the SED group, while 17 age-matched LEX men (aged 60±5years) also participated as a positive comparison group. In SED, preconditioning (P=0.030, d=0.34) and HIIT (P=0.030, d=0.48) caused a reduction in IL-6 compared to enrollment. SED homocysteine did not change throughout (P>0.57; d<0.26), while the decrease in hsCRP after preconditioning (P=0.486, d=0.25) and after HIIT (P=0.781, d=0.23) compared to enrollment was small. HIIT did not influence IL-6 or hsCRP in LEX (all P>0.42; d<0.3). Homocysteine increased from enrollment to post-HIIT in LEX (P=0.144, d=0.83), but all other perturbations were trivial. IL-6 and hsCRP were greater in SED than LEX throughout the investigation (all P<0.029; d>0.72), but homocysteine was not different (all P >0.131; d<0.41). Results of this study suggest moderate-intensity aerobic exercise and HIIT lowers IL-6 (and possible hsCRP) in previously sedentary older men. Moreover, lifelong exercise is associated with reduced concentrations of some inflammatory biomarkers in older males, and therefore, physical activity, rather than age per se, is implicated in chronic low-grade inflammation. Moreover, physical inactivity-induced inflammation may be partly salvaged by short-term exercise training.

Six weeks of high intensity interval training (HIIT) facilitates a four year preservation of aerobic capacity in sedentary older males: A reunion study.

Long-term implications of acutely increased cardiorespiratory fitness following short-term exercise interventions in older adults are unknown. In this study, we examined peak oxygen uptake (VO2peak) after 4-years of 'free-living' after a high intensity interval training (HIIT) intervention. Seventeen lifelong exercisers (LEX) and 17 previously sedentary (SED) males (55-74 years of age in 2012) were tested four years (phase D) after our previous experiment which included 6-weeks of aerobic moderate intensity exercise (phase B), followed by 6-weeks of HIIT (phase C). At all stages, a standard incremental exercise protocol on a cycle ergometer was completed to determine VO2peak. SED (P = 1.000, Cohen's d = 0.01) and LEX (P = 1.000, Cohen's d = 0.11) VO2peak at phase D was not different from phase A (enrolment). SED experienced a large decrease in VO2peak from phase C to phase D (32 ± 6 ml·kg·min-1 to 27 ± 6 ml·kg·min-1 [P < 0.001, Cohen's d = 0.81]). LEX experienced a small decrease in VO2peak from phase C to phase D (42 ± 7 ml·kg·min-1 to 39 ± 9 ml·kg·min-1 [P < 0.001, Cohen's d = 0.46]). At phase D, LEX had greater VO2peak than SED (P < 0.001, Cohen's d = 1.73). The proportion of subjects who reported discontinuing training, maintaining moderate training, and maintaining HIIT differed between groups (P = 0.023), with LEX self-reporting more HIIT, and SED self-reporting more discontinuation from exercise. Those who continued exercising experienced a reduction in VO2peak over the four years from 39 ± 7 ml·kg·min-1 to 36 ± 9 ml·kg·min-1 (N = 25, P < 0.001, Cohen's d = 0.37), and those who discontinued exercising also experienced a reduction in VO2peak from 30 ± 7 ml·kg·min-1 to 25 ± 9 ml·kg·min-1 (N = 9, P = 0.003, Cohen's d = 0.62). Four years after completing a brief period of aerobic exercise and HIIT, older males demonstrated a preservation of VO2peak, irrespective of training status (LEX or SED). However, LEX exhibited greater VO2peak than SED after 4-years of unsupervised 'free-living'. Notably, participants who discontinued exercising experienced a greater reduction in VO2peak. These data suggest that a 6 weeks of supervised HIIT can facilitate the long term.

Sprint Interval Training and the School Curriculum: Benefits Upon Cardiorespiratory Fitness, Physical Activity Profiles, and Cardiometabolic Risk Profiles of Healthy Adolescents.

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 × 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.

Aerobic Training Protects Cardiac Function During Advancing Age: A Meta-Analysis of Four Decades of Controlled Studies.

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.

Electromyographic analyses of the erector spinae muscles during golf swings using four different clubs.

The purpose of this study was to compare the electromyography (EMG) patterns of the thoracic and lumbar regions of the erector spinae (ES) muscle during the golf swing whilst using four different golf clubs. Fifteen right-handed male golfers performed a total of twenty swings in random order using the driver, 4-iron, 7-iron and pitching-wedge. Surface EMG was recorded from the lead and trail sides of the thoracic 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-activation levels from the lead and trail sides of the thoracic and lumbar regions of the ES muscle were displayed between the driver, 4-iron, 7-iron and pitching-wedge (P > 0.05). The highest mean thoracic and lumbar ES 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 were no significant statistical differences between the driver, 4-iron, 7-iron and pitching-wedge when examining muscle activity from the thoracic and lumbar regions of the ES muscle.

Commercial golf glove effects on golf performance and forearm muscle activity.

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.

Lifelong exercise, but not short-term high-intensity interval training, increases GDF11, a marker of successful aging: a preliminary investigation.

Lifelong exercise is associated with regulation of skeletal mass and function, reductions in frailty, and successful aging. Yet, the influence of exercise on myostatin and myostatin-interacting factors is relatively under examined in older males. Therefore, we investigated whether serum total myostatin, free myostatin, follistatin, and growth and differentiation factor 11 (GDF11) were altered following high-intensity interval training (HIIT) in a group of 13 lifelong sedentary (SED; 64 [6] years) and 11 lifelong exercising (LEX; 62 [6] years) older males. SED follistatin was moderately greater than LEX pre-HIIT (Cohen's d = 0.66), and was largely greater post-HIIT (Cohen's d = 1.22). The HIIT-induced increase in follistatin was large in SED (Cohen's d = 0.82) and absent in LEX (Cohen's d = 0.03). GDF11 was higher in LEX pre-HIIT (Cohen's d = 0.49) and post-HIIT (Cohen's d = 0.63) compared to SED HIIT resulted in no change to GDF11 in LEX or SED (Cohen's d = 0.00-0.03). Peak power output and GDF11 were correlated (r = 0.603), independent of grouping. Differences in GDF11 with lifelong exercise training, paired with the correlation between GDF11 and peak power output, suggested that GDF11 may be a relevant myostatin-interacting peptide to successful aging in humans, and strategies to maintain this need to be further explored.

Exercise training improves free testosterone in lifelong sedentary aging men.

As the impact of high-intensity interval training (HIIT) on systemic hormones in aging men is unstudied to date, we investigated whether total testosterone (TT), sex hormone-binding globulin (SHBG), free testosterone (free-T) and cortisol (all in serum) were altered following HIIT in a cohort of 22 lifelong sedentary (62 ± 2 years) older men. As HIIT requires preconditioning exercise in sedentary cohorts, participants were tested at three phases, each separated by six-week training; baseline (phase A), following conditioning exercise (phase B) and post-HIIT (phase C). Each measurement phase used identical methods. TT was significantly increased following HIIT (~17%; P < 0.001) with most increase occurring during preconditioning (~10%; P = 0.007). Free-T was unaffected by conditioning exercise (P = 0.102) but was significantly higher following HIIT compared to baseline (~4.5%; P = 0.023). Cortisol remained unchanged from A to C (P = 0.138). The present data indicate a combination of preconditioning, and HIIT increases TT and SHBG in sedentary older males, with the HIIT stimulus accounting for a small but statistically significant increase in free-T. Further study is required to determine the biological importance of small improvements in free-T in aging men.

Comparison of Thoracic and Lumbar Erector Spinae Muscle Activation Before and After a Golf Practice Session.

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 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.

High-intensity interval training (HIIT) increases insulin-like growth factor-I (IGF-I) in sedentary aging men but not masters' athletes: an observational study.

INTRODUCTION: The aim of this investigation was to examine the impact high-intensity interval training (HIIT) on serum insulin-like growth factor-I (IGF-I) in active compared with sedentary aging men. METHODS: 22 lifetime sedentary (SED; 62 ± 2 years) and 17 masters' athletes (LEX; 60 ± 5 years) were recruited to the study. As HIIT requires preconditioning exercise in sedentary cohorts, the study required three assessment phases; enrollment (phase A), following preconditioning exercise (phase B), and post-HIIT (phase C). Serum IGF-I was determined by electrochemiluminescent immunoassay. RESULTS: IGF-I was higher in LEX compared to SED at baseline (p = 0.007, Cohen's d = 0.91), and phase B (p = 0.083, Cohen's d = 0.59), with only a small difference at C (p = 0.291, Cohen's d = 0.35). SED experienced a small increase in IGF-I following preconditioning from 13.1 ± 4.7 to 14.2 ± 6.0 µg·dl-1 (p = 0.376, Cohen's d = 0.22), followed by a larger increase post-HIIT (16.9 ± 4.4 µg·dl-1), which was significantly elevated compared with baseline (p = 0.002, Cohen's d = 0.85), and post-preconditioning (p = 0.005, Cohen's d = 0.51). LEX experienced a trivial changes in IGF-I from A to B (18.2 ± 6.4 to 17.2 ± 3.7 µg·dl-1 [p = 0.538, Cohen's d = 0.19]), and a small change post-HIIT (18.4 ± 4.1 µg·dl-1 [p = 0.283, Cohen's d = 0.31]). Small increases were observed in fat-free mass in both groups following HIIT (p < 0.05, Cohen's d = 0.32-0.45). CONCLUSIONS: In conclusion, HIIT with preconditioning exercise abrogates the age associated difference in IGF-I between SED and LEX, and induces small improvements in fat-free mass in both SED and LEX.

Utility of three anthropometric indices in assessing the cardiometabolic risk profile in children.

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.

An electromyographic study of the effect of hand grip sizes on forearm muscle activity and golf performance.

The study describes the differences in surface electromyography (EMG) activity of two forearm muscles in the lead and trail arm at specific phases of the golf swing using a 7-iron with three different grip sizes among amateur and professional golfers. Fifteen right-handed male golfers performed five golf swings using golf clubs with three different grip sizes. Surface EMG was used to measure muscle activity of the extensor carpi radialis brevis (ECRB) and flexor digitorum superficialis (FDS) on both forearms. There were no significant differences in forearm muscle activity when using the three golf grips within the group of 15 golfers (p > 0.05). When using the undersize grip, club head speed significantly increased (p = 0.044). During the backswing and downswing phases, amateurs produced significantly greater forearm muscle activity with all three grip sizes (p < 0.05). In conclusion, forearm muscle activity is not affected by grip sizes. However, club head speed increases when using undersize grips.

Observation of Age-Related Decline in the Performance of the Transverse Abdominis Muscle.

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.

Prolonged androgenic anabolic steroid (AAS) induced QT interval shortening: a suitable screening tool?

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.