Dr John Jakeman

Evidence investigating skilled performers in sport suggests that a prominent component of skilled behaviour is, in part, due to the development of more effective and efficient perception-action couplings. Further, the Quiet Eye has emerged as a useful tool in which to investigate how skilled performers regulate action through fixating on visual information within the immediate environment before the onset of a goal directed movement. However, only a few contributions to the literature have attempted to examine the individual variations within these Quiet Eye fixations in skilled participants. In this case study, we first asked how goalkeepers control their actions, via the Quiet Eye in a representative task. Second, we sought to examine whether inter- and intra- individual differences in the Quiet Eye are present in skilled goalkeepers as a functional component of skilled performance. Results were consistent with previous work on football goalkeepers, with QE fixations located at the ball and visual pivot. However, individual analysis reveals different Quiet Eye gaze patterning between (inter) and within (intra) the goalkeepers during saving actions. To conclude, we have provided a descriptive case study in attempt to understand the Quiet Eye behaviours of a skilled sample of professional goalkeepers. In doing so we have suggested how adaptive variability, founded upon an Ecological Dynamics framework, may provide further insight into the function of the Quiet Eye.

Sprint interval training (SIT) has been shown to be effective at improving athletic performance in laboratory studies, but the efficacy of SIT programs incorporated into normal training schedules is poorly considered. This study aimed to investigate the impact of a running SIT intervention applied to competitive athletes within a training program and to consider whether an uphill or flat (horizontal) SIT protocol had different effects on performance changes over time. Eighteen male hockey players (mean ± SD: age, 20.7 ± 0.9 years; hockey training experience, 9.9 ± 3.0 years) completed 2 sessions of SIT per week for 8 weeks, with intensity progressively increasing from 6 sprints in week 1 to 12 sprints in week 8. Subjects were randomly allocated to a flat or uphill (6% gradient) training condition (n = 9) and completed 30-m maximal sprint efforts with a 30-second recovery. Performance measures, including squat jump, 30-m sprint speed, and repeated sprint time, all improved significantly (p ≤ 0.05). Squat jump performance improved by 3.84 (d = 0.8) and 3.55 (d = 0.7) in the flat and uphill groups, respectively. Thirty-meter sprint speed improved by 0.06 (d = −0.4) and 0.10 (d = −0.7), and repeated sprint performance also improved, with the fastest of recorded sprints after intervention being 0.06 and 0.04 faster in the flat and uphill groups, respectively. Supplementing a normal hockey training week with SIT can have a positive impact on performance measures in male university hockey players. Furthermore, using an uphill training modality had a small, nonsignificant additional positive effect to some performance adaptations.

Objectives.
To assess physical activity (PA), mental health and well-being of adults in the United Kingdom (UK), Ireland, New Zealand and Australia during the initial stages of National governments’ Coronavirus disease (COVID-19) containment responses.

Design.
Observational, cross-sectional.

Methods.
An online survey was disseminated to adults (n = 8,425; 44.5 ± 14.8y) residing in the UK, Ireland, New Zealand and Australia within the first 2-6 weeks of government-mandated COVID-19 restrictions. Main outcome measures included: Stages of Change scale for exercise behaviour change; International Physical Activity Questionnaire (short-form); World Health Organisation-5 Well-being Index; and the Depression Anxiety and Stress Scale-9.

Results.
Participants who reported a negative change in exercise behaviour from before initial COVID-19 restrictions to during the initial COVID-19 restrictions demonstrated poorer mental health and well-being compared to those demonstrating either a positive-or no change in their exercise behaviour (p

Conclusion.
The initial COVID-19 restrictions have differentially impacted upon PA habits of individuals based upon their age and sex, and therefore have important implications for international policy and guideline recommendations. Public health interventions that encourage PA should target specific groups (e.g., men, young adults) who are most vulnerable to the negative effects of physical distancing and/or self-isolation.

Sprint interval training (SIT) has been shown to improve performance measures in a range of individuals, and it is understood that different responses can be elicited from different training protocols. However, consideration of changes in work: rest ratios could offer important insight into optimising training programmes. The purpose of this study was to investigate the effect of three different work: rest ratios on exercise performance. 

Thirty-six male and female participants were randomly allocated to one of three training groups, or a non-training control group. Training consisted of 10x6 second ‘all-out’ sprints on a cycle ergometer, with a 1:8, 1:10 or 1:12 work: rest ratio. Performance data, including peak power output, performance decrement, and 10km time trial performance data were collected before and after 2-weeks of SIT.

There were significant (p ≤ 0.05) improvements in all parameters for the training groups, but no changes in the control condition. Peak power increased by 57.2W, 50.7W and 53.7W in the 1:8, 1:10 and 1:12 groups respectively, with no significant differences in response between conditions. Time trial performance improved significantly in all three training conditions (29.4s, 8.7s, and 25.1s in the 1:8, 1:10 and 1:12 groups), while worsening in the control group.

All training conditions resulted in significant improvements in performance, but there were no significant differences in improvement for any of the groups. Any of the three stated work: rest ratios would be appropriate for use with athletes and allow some level of personal preference for those interested in using the protocol.

Purpose: The purpose of this study was to determine the typical variation of variables from a countermovement jump (CMJ) test and a submaximal run test (SRT), along with comparing the sensitivity of each test for the detection of practically important changes within high-performance Australian rules football (ARF) players. Methods: 23 professional and semi-professional ARF players, performed six CMJs and three, eight-second 50-meter runs every 30 s (SRT), seven days apart. Absolute and trial-to-trial reliability was represented as a coefficient of variation (CV) +/- 90% confidence intervals (CI). Test-retest reliability was examined using the magnitude of the difference (effect size (ES) ± 90% CI) from week 1 to week 2. The smallest worthwhile change (SWC) was calculated as 0.25 x SD. Results: Good reliability (CVs = 6.6 – 9.3%) was determined for all variables except eccentric displacement (CV = 12.8%), with no clear changes observed in any variables between week 1 and week 2. All variables from the SRT possessed a CV

Purpose: To compare the sensitivity of a submaximal run test (SRT) with a countermovement-jump test (CMJ) to provide an alternative method of measuring neuromuscular fatigue (NMF) in high-performance sport. Methods: A total of 23 professional and semiprofessional Australian rules football players performed an SRT and CMJ test prematch and 48 and 96 h postmatch. Variables from accelerometers recorded during the SRT were player load 1D up (vertical vector), player load 1D side (mediolateral vector), and player load 1D forward (anteroposterior vector). Meaningful difference was examined through magnitude-based inferences (effect size [ES]), with reliability assessed as typical error of measurements expressed as coefficient of variance. Results: A small decrease in CMJ height, ES −0.43 ± 0.39 (likely), was observed 48 h postmatch before returning to baseline 96 h postmatch. This was accompanied by corresponding moderate decreases in the SRT variables player load 1D up, ES −0.60 ± 0.51 (likely), and player load 1D side, ES −0.74 ± 0.57 (likely), 48 h postmatch before also returning to prematch baseline. Conclusion: The results suggest that in the presence of NMF, players use an alternative running profile to produce the same external output (ie, time). This indicates that changes in accelerometer variables during an SRT can be used as an alternative method of measuring NMF in high-performance Australian rules football and provides a flexible option for monitoring changes in the recovery phase postmatch.

This study sought to compare early physiological and performance adaptations between a two-week cycle sprint interval training (SIT) and uphill run sprint training (UST) programs. Seventeen recreationally active adult males (age = 28 ± 5 years; body mass (BM) = 78 ± 9 kg) were assigned to either a control (n = 5), SIT (n = 6), or UST (n = 6) group. A discrete group of participants (n = 6, age = 33 ± 6 years, and body mass = 80 ± 9 kg) completed both training protocols to determine acute physiological responses. Intervention groups completed either a run or cycle peak oxygen uptake (VO2peak) test (intervention type dependent) prior to and following two weeks of training. Training comprised of three sessions per week of 4 × 30-s “all-out” sprints with a four-minute active recovery between bouts on a cycle ergometer against 7.5% of body mass in the SIT group and on a 10% slope in the UST group. The VO2peak values remained unchanged in both training groups, but time-to-exhaustion (TTE) was significantly increased only in the UST group (pre—495 ± 40 s, post—551 ± 15 s; p = 0.014) and not in the SIT group (pre—613 ± 130 s, post—634 ± 118 s, p = 0.07). Ventilatory threshold (VT) was significantly increased in both training groups (SIT group: pre—1.94 ± 0.45 L·min−1, post—2.23 ± 0.42 L·min−1; p

Design. Randomised-controlled trial.

Methods. Thirty physically active males were randomly allocated to one of two sprint training groups: a 6 s group, a 30 s group or a non-exercising control. The training groups were matched for work:rest ratio and total sprint time per session, and completed 6 training sessions over a 2-week period. Before and after the 2 week training period, participants completed a VO2max test and a 10 km time trial on a cycle ergometer.

Results. Time trial performance increased significantly by 5.1% in 6 s (630 ± 115 s to 598 ± 92 s; p < 0.05) and 6.2% in 30 s (579 ± 68 s to 543 ± 85 s; p < 0.05) from baseline testing, but there was no significant change in the control group (p > 0.05), and no significant difference between exercise groups (p > 0.05). The 6 s group increased peak power output by 9.0% (from 1092 ± 263 W to 1181 ± 248 W; p < 0.05) from sprint session 1 to 6, and the 30 s group by 20.0% (1041 ± 161 W to 1237 ± 159 W; p < 0.05).

Conclusions. This study indicates that both 6 and 30 s bouts of repeated sprint exercise, matched for total sprint duration and W:R can improve athletic performance.

Nitrate ingestion from beetroot juice (BR) has the capabilities to enhance muscle contractile efficiency, and potentially improve exercise tolerance (Ferguson et al., 2013, Journal of Physiology, 591(2), 547–557.) Delaying the onset of fatigue is vital in athletes, potentially contributing to increased power or duration. Although recent work has demonstrated the positive impact of nitrate on muscle twitch characteristics (Haider and Folland, 2014, Medicine and Science in Sport and Exercise, 46, 2234–2243) to date, no work has assessed the impact of nitrate supplementation on the maintenance of muscle contractile characteristics following high-intensity bouts of exercise. Following university ethical approval, in a randomised double-blind study, 19 males (age: 23 ± 4 years) firstly completed a high-intensity training bout prior to then consuming either BR (NO3−: 0.6 g · day−1) or PL (insignificant nitrate content) for six consecutive days. Following supplementation, the high-intensity training bout was repeated. The high-intensity training bouts consisted of four 30-s Wingate Anaerobic sprint tests, separated by 4 min recovery. Immediately pre and prior to the exercise bouts, participants performed three maximal single-leg isometric contractions, with peripheral magnetic stimulation applied at rest and during maximal voluntary contractions (MVC) for the assessment of peripheral voluntary activation (PVA), resting twitch (RT), maximal rate of torque development (MRTD) and half relaxation time (0.5RT). Mean and peak power during the high-intensity training bout showed no improvement after BR when compared to PL (1035 ± 120.2 W vs. 1079 ± 242.6 W, P > 0.05). There was no improvement in the maintenance of MVC, resting twitch (RT), PVA and half relaxation time (HRT) following BR supplementation. However, in the BR group maximal rate of force development (MRFD) was maintained to a greater extent than PL (ES = 0.45, P ≤ 0.05). MRFD fell by 66.8 ± 20.5% in PL, whereas only 48.2 ± 16.3% in BR after the high-intensity bouts. BR supplementation maintained MRFD, improving muscle contractile efficiency on fatigued fibres; however, results suggest that it doesn’t produce improved performance in high-intensity training bouts. No improvements in power production, combined with no significant changes in MVC and RT, indicate that individuals were equally as fatigued and could not produce greater force after supplementation. Although supplementation did not lead to improvements in high-intensity exercise performance, the improved maintenance of MRFD may have implications for training adaptations and performance, particularly when undertaking multiple sessions in a day.