Increasing the longitudinal bending stiffness of runners’ habitual shoes: An appropriate choice for improving running performance?

This study analysed the effects of increasing the longitudinal bending stiffness (LBS) of runners’ habitual shoes on the metabolic energetic demand, lower limb muscle activation and stride spatiotemporal parameters during a prolonged running session through classical group investigation, as well as a more individualised approach. Eleven recreational male participants ran overground for 40 min at 95% of their ventilatory anaerobic threshold with their own shoes or their shoes with higher LBS (stiff carbon plate inserted under insole). The net energetic cost of running, lower leg muscle activation and spatiotemporal parameters were measured during the prolonged running. The variables of interest were analysed for 1 min in seven time intervals. There were no main effects of LBS or interaction effects with running duration on the group averaged variables. Overall, the participant-specific metabolic effects induced by an increased shoe LBS were not beneficial. Beneficial metabolic effects were more likely to occur when the increased LBS induced a decrease or no change in the ground contact time relative to their habitual shoes, as well as for taller runners. Increasing the LBS in runners’ habitual shoes did not induce systematic metabolic effects for all the runners and may not be beneficial for performance purposes if the runners’ shoe habits were too disrupted.

The Effect of Eight-Week Sprint Interval Training on Aerobic Performance of Elite Badminton Players

This study was aimed to: (1) investigate the effects of physiological functions of sprint interval training (SIT) on the aerobic capacity of elite badminton players; and (2) explore the potential mechanisms of oxygen uptake, transport and recovery within the process. Thirty-two elite badminton players volunteered to participate and were randomly divided into experimental (Male-SIT and Female-SIT group) and control groups (Male-CON and Female-CON) within each gender. During a total of eight weeks, SIT group performed three times of SIT training per week, including two power bike trainings and one multi-ball training, while the CON group undertook two Fartlek runs and one regular multi-ball training. The distance of YO-YO IR2 test (which evaluates player’s ability to recover between high intensity intermittent exercises) for Male-SIT and Female-SIT groups increased from 1083.0 ± 205.8 m to 1217.5 ± 190.5 m, and from 725 ± 132.9 m to 840 ± 126.5 m (p < 0.05), respectively, which were significantly higher than both CON groups (p < 0.05). For the Male-SIT group, the ventilatory anaerobic threshold and ventilatory anaerobic threshold in percentage of VO2max significantly increased from 3088.4 ± 450.9 mL/min to 3665.3 ± 263.5 mL/min (p < 0.05),and from 74 ± 10% to 85 ± 3% (p < 0.05) after the intervention, and the increases were significantly higher than the Male-CON group (p < 0.05); for the Female-SIT group, the ventilatory anaerobic threshold and ventilatory anaerobic threshold in percentage of VO2max were significantly elevated from 1940.1 ± 112.8 mL/min to 2176.9 ± 78.6 mL/min, and from 75 ± 4% to 82 ± 4% (p < 0.05) after the intervention, which also were significantly higher than those of the Female-CON group (p < 0.05). Finally, the lactate clearance rate was raised from 13 ± 3% to 21 ± 4% (p < 0.05) and from 21 ± 5% to 27 ± 4% for both Male-SIT and Female-SIT groups when compared to the pre-test, and this increase was significantly higher than the control groups (p < 0.05). As a training method, SIT could substantially improve maximum aerobic capacity and aerobic recovery ability by improving the oxygen uptake and delivery, thus enhancing their rapid repeated sprinting ability.

Abstract 14404: The Fontan Udenafil Exercise Longitudinal Trial Subgroup Analysis

Background: The Pediatric Heart Network’s Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT 02741115) demonstrated improvements in exercise capacity and ventricular performance following six months of treatment with udenafil (87.5 mg twice daily). In this analysis we evaluated whether subgroups within the population experienced a differential effect on exercise performance in response to treatment. Methods: The effect of udenafil on exercise was evaluated within subgroups defined by gender, race, ventricular morphology, and baseline peak oxygen consumption (VO 2 ). Linear regression modeling evaluated for differential response to udenafil (interaction of subgroup with treatment arm). Individual subgroups were excluded if the number of participants was <5% of total. As the FUEL Trial was not powered for subgroup analysis, all analyses were viewed as exploratory. Results: Subgroup analyses demonstrated qualitative improvements in peak VO 2 , work rate at the ventilatory anaerobic threshold (VAT), VO 2 at VAT, and ventilatory efficiency (VE/VCO 2 ) for those randomized to udenafil compared to placebo in all subgroups (Table). There was not a differential response to udenafil based on gender, race, ventricular morphology, or baseline peak VO 2 , although participants in the lowest tertile of baseline peak VO 2 and those with single left ventricles trended toward larger improvements. Conclusion: The relatively uniform improvement among subgroups in response to treatment with udenafil is consistent with the findings from the primary analysis of the FUEL trial. While the absence of a statistically significant differential effect between subgroups suggests that the effect of udenafil may not be gender, race, or morphology specific, and may not vary based on baseline exercise performance, the possibility of a larger improvements in those with poor baseline peak VO 2 and those with single left ventricle warrants further investigation.

Study protocol of a single-arm pre-post study to assess the preliminary effectiveness and feasibility of a home-based bimodal prehabilitation program on preoperative aerobic fitness in high-risk patients scheduled for liver or pancreatic resection

<p class="abstract"><strong>Background:</strong> Controversial evidence currently exists regarding the feasibility and effectiveness to improve preoperative aerobic fitness during home-based prehabilitation in patients scheduled for liver or pancreatic resection, whereas morbidity rates are high following these resections. The primary aim of this study is to evaluate the preoperative oxygen uptake (VO₂) at the ventilatory anaerobic threshold before and after a four-week home-based preoperative training program with nutritional supplementation in high-risk patients scheduled for elective liver or pancreatic resection. Secondary aims are to evaluate program feasibility, immune system function, cardiopulmonary exercise test responses, individual progression profiles on training responses, quality of life, and postoperative course.</p><p class="abstract"><strong>Methods:</strong> In this multicenter study with a pretest-posttest design, patients with a liver or pancreatic tumor scheduled for elective resection will be recruited. To select the high-risk fraction of this surgical population, their VO₂ at the ventilatory anaerobic threshold should be &lt;11 ml/kg/min for final inclusion. A planned total of 24 high-risk patients will participate in a four-week (three sessions per week) home-based bimodal prehabilitation program. The partly supervised home-based preoperative training program consists of individualized goal setting followed by titration of interval and endurance training on an advanced cycle ergometer, combined with functional task exercises. Additionally, patients will be given protein and vitamin/mineral supplementation.</p><p class="abstract"><strong>Discussion: </strong>Effects of a partly supervised home-based bimodal prehabilitation regimen are unknown in high-risk patients opting for liver or pancreatic resection. Improved preoperative aerobic fitness might translate into improved postoperative outcomes and a reduced demand on care resources.</p><p class="abstract"><strong>Trial Registration:</strong> The study is registered in the Netherlands Trial Registry (NL6151) and was approved by the Institutional Ethics Committee, Twente, Enschede, the Netherlands (P17-08).</p>

P138 IMPACT OF NEOADJUVANT FLOT CHEMOTHERAPY ON CARDIORESPIRATORY RESERVE OF PATIENTS WITH OESOPHAGOGASTRIC ADENOCARCINOMA

Introduction Neoadjuvant chemotherapy is known to have a deleterious effect on the cardiorespiratory reserve of patients with oesophagogastric cancer[1,2]. A low anaerobic threshold is associated with increased morbidity after major surgery[3] The effect that FLOT (5FU, leucovorin, oxaliplatin, docetakel) chemotherapy has upon cardiopulmonary reserve has not been reported. This work aims to quantify this effect. Methods Cardiopulmonary exercise testing (CPET) was completed in 18 consecutive patients with oesophagogastric cancer who received FLOT chemotherapy. CPET pre-chemotherapy and 4-5weeks post-chemotherapy measured the ventilatory anaerobic threshold (AT) and peak oxygen uptake (Vo2p). Ventilatory equivalents for CO2 (Ve/VCO2) and total ventilation (Ve) were reported. The group mean change in these objective measurements of cardiopulmonary reserve was compared before and after FLOT. Results Between October 2018 and January 2019 eighteen patients (median age 58.1 years, 16/18 male) were tested before and after FLOT. In 14 patients (78%) a decline in AT and VO2p was demonstrated. A mean decrease in AT of 2.1 mlkg-1min-1 (14.9 Vs 12.8 mlkg-1min-1, p=0.02) and VO2p of 2.3 mlkg-1min-1 (20.6 vs 18.3 mlkg-1min-1, p=0.01) was seen after FLOT. Ve/VCO2 and Ve were unchanged. Conclusion Patients receiving FLOT chemotherapy demonstrate a clinically significant decrease in cardiorespiratory reserve. This appears to be similar to that observed in patients who have previously received neoadjuvant ECX (MAGIC regimen) [1,2,4]. Further investigation into the clinical impact of this observation is required.

Interobserver variability of ventilatory anaerobic threshold in asymptomatic volunteers

Background: The ventilatory anaerobic threshold (VO2@AT) has been used in preoperative risk assessment and rehabilitation for many years. Our aim was to determine the interobserver variability of AT using cardiopulmonary exercise (CPET) data from a large epidemiological study (SHIP, Study of Health in Pomerania). Methods: VO2@AT was determined from CPET of 1,079 cross-sectional volunteers, according to American Heart Association guidelines. VO2@AT determinations were compared between two experienced physicians, between physicians and qualified medical assistants, and between physicians or medical assistants and software-based algorithms. For the first 522 data sets, the two physicians discussed discrepant readings to reach consensus; the remaining data sets were analyzed without consensus discussion. Results: VO2@AT was detectable in 1,056 data sets. The physicians recorded identical VO2@AT values in 319 out of 522 cases before consensus discussion (61.1%; intraclass correlation coefficient [ICC]: 0.90; 95% confidence interval [CI]: 0.88–0.92) and in 700 out of 1,056 cases overall (66.3%; ICC: 0.95; 95% CI: 0.95–0.96), with an interobserver difference of 0 ± 8% (95% limits of agreement [LOA]: ±161 mL/min). The interobserver difference was − 2 ± 18% (95% LOA: ±418 mL/min) between a physician and medical assistants, and − 19 ± 24% to − 22 ± 26% (95% LOAs: ±719–806 mL/min) between physicians or medical assistants and software-based algorithms. Conclusions: Experienced physicians show high agreement when determining AT in asymptomatic volunteers. However, agreement between physicians and qualified medical assistants is lower, and there is substantial deviation in AT determination between physicians or medical assistants and software-based algorithms. This must be considered when using AT as a decision tool.

Does exercise prescription based on estimated heart rate training zones exceed the ventilatory anaerobic threshold in patients with coronary heart disease undergoing usual-care cardiovascular rehabilitation? A United Kingdom perspective

Background In the United Kingdom (UK), exercise intensity is prescribed from a fixed percentage range (% heart rate reserve (%HRR)) in cardiac rehabilitation programmes. We aimed to determine the accuracy of this approach by comparing it with an objective, threshold-based approach incorporating the accurate determination of ventilatory anaerobic threshold (VAT). We also aimed to investigate the role of baseline cardiorespiratory fitness status and exercise testing mode dependency (cycle vs. treadmill ergometer) on these relationships. Design and methods A maximal cardiopulmonary exercise test was conducted on a cycle ergometer or a treadmill before and following usual-care circuit training from two separate cardiac rehabilitation programmes from a single region in the UK. The heart rate corresponding to VAT was compared with current heart rate-based exercise prescription guidelines. Results We included 112 referred patients (61 years (59–63); body mass index 29 kg·m–2 (29–30); 88% male). There was a significant but relatively weak correlation ( r = 0.32; p = 0.001) between measured and predicted %HRR, and values were significantly different from each other ( p = 0.005). Within this cohort, we found that 55% of patients had their VAT identified outside of the 40–70% predicted HRR exercise training zone. In the majority of participants (45%), the VAT occurred at an exercise intensity <40% HRR. Moreover, 57% of patients with low levels of cardiorespiratory fitness achieved VAT at <40% HRR, whereas 30% of patients with higher fitness achieved their VAT at >70% HRR. VAT was significantly higher on the treadmill than the cycle ergometer ( p < 0.001). Conclusion In the UK, current guidelines for prescribing exercise intensity are based on a fixed percentage range. Our findings indicate that this approach may be inaccurate in a large proportion of patients undertaking cardiac rehabilitation.