Confirming the attainment of maximal oxygen uptake within special and clinical groups: A systematic review and meta-analysis of cardiopulmonary exercise test and verification phase protocols

BACKGROUND AND AIM

A plateau in oxygen uptake ([Formula: see text]) during an incremental cardiopulmonary exercise test (CPET) to volitional exhaustion appears less likely to occur in special and clinical populations. Secondary maximal oxygen uptake ([Formula: see text]) criteria have been shown to commonly underestimate the actual [Formula: see text]. The verification phase protocol might determine the occurrence of 'true' [Formula: see text] in these populations. The primary aim of the current study was to systematically review and provide a meta-analysis on the suitability of the verification phase for confirming 'true' [Formula: see text] in special and clinical groups. Secondary aims were to explore the applicability of the verification phase according to specific participant characteristics and investigate which test protocols and procedures minimise the differences between the highest [Formula: see text] values attained in the CPET and verification phase.

METHODS

Electronic databases (PubMed, Web of Science, SPORTDiscus, Scopus, and EMBASE) were searched using specific search strategies and relevant data were extracted from primary studies. Studies meeting inclusion criteria were systematically reviewed. Meta-analysis techniques were applied to quantify weighted mean differences (standard deviations) in peak [Formula: see text] from a CPET and a verification phase within study groups using random-effects models. Subgroup analyses investigated the differences in [Formula: see text] according to individual characteristics and test protocols. The methodological quality of the included primary studies was assessed using a modified Downs and Black checklist to obtain a level of evidence. Participant-level [Formula: see text] data were analysed according to the threshold criteria reported by the studies or the inherent measurement error of the metabolic analysers and displayed as Bland-Altman plots.

RESULTS

Forty-three studies were included in the systematic review, whilst 30 presented quantitative information for meta-analysis. Within the 30 studies, the highest mean [Formula: see text] values attained in the CPET and verification phase protocols were similar (mean difference = -0.00 [95% confidence intervals, CI = -0.03 to 0.03] L·min-1, p = 0.87; level of evidence, LoE: strong). The specific clinical groups with sufficient primary studies to be meta-analysed showed a similar [Formula: see text] between the CPET and verification phase (p > 0.05, LoE: limited to strong). Across all 30 studies, [Formula: see text] was not affected by differences in test protocols (p > 0.05; LoE: moderate to strong). Only 23 (53.5%) of the 43 reviewed studies reported how many participants achieved a lower, equal, or higher [Formula: see text] value in the verification phase versus the CPET or reported or supplied participant-level [Formula: see text] data for this information to be obtained. The percentage of participants that achieved a lower, equal, or higher [Formula: see text] value in the verification phase was highly variable across studies (e.g. the percentage that achieved a higher [Formula: see text] in the verification phase ranged from 0% to 88.9%).

CONCLUSION

Group-level verification phase data appear useful for confirming a specific CPET protocol likely elicited [Formula: see text], or a reproducible [Formula: see text], for a given special or clinical group. Participant-level data might be useful for confirming whether specific participants have likely elicited [Formula: see text], or a reproducible [Formula: see text], however, more research reporting participant-level data is required before evidence-based guidelines can be given.

TRIAL REGISTRATION

PROSPERO (CRD42021247658) https://www.crd.york.ac.uk/prospero.

Can mixed circuit training elicit the recommended exercise intensity and energy expenditure in people after stroke?

PURPOSE

To investigate whether mixed circuit training (MCT) elicits the recommended exercise intensity and energy expenditure in people after stroke, and to establish the between-day reproducibility for the percentages of heart rate reserve (%HRR), oxygen uptake reserve (%VO2R), and energy expenditure elicited during two bouts of MCT.

METHODS

Seven people aged 58 (12) yr, who previously had a stroke, performed a cardiopulmonary exercise test, a non-exercise control session, and two bouts of MCT. The MCT included 3 circuits of 10 resistance exercises at 15-repetition maximum intensity, with each set of resistance exercise interspersed with 45-s of walking. Expired gases were collected during the MCT and control session and for 40 min afterward. Control session was necessary to calculate the net energy expenditure associated with each bout of MCT.

RESULTS

Mean %VO2R (1st MCT: 51.1%, P = .037; 2nd MCT: 54.0%, P = .009) and %HRR (1st MCT: 66.4%, P = .007; 2nd MCT: 67.9%, P = .010) exceeded the recommended minimum intensity of 40%. Both %VO2R (P = .586 and 0.987, respectively) and %HRR (P = .681 and 0.237, respectively) during the 1st and 2nd bouts of MCT were not significantly different to their corresponding gas exchange threshold values derived from cardiopulmonary exercise testing. Mean net total energy expenditure significantly exceeded the minimum recommend energy expenditure in the 1st (P = .048) and 2nd (P = .023) bouts of MCT. Between-day reproducibility for %HRR, %VO2R, and energy expenditure was excellent (ICC: 0.92-0.97).

CONCLUSIONS

MCT elicited physiological strain recommended for improving health-related fitness in people after stroke and these responses demonstrated excellent between-day reproducibility.

ACTivity as medicine In Oncology for Head and Neck (ACTIOHN): Protocol for a feasibility study investigating a patient-centred approach to exercise for people with head and neck cancer

BACKGROUND AND AIM

Attempts at personalisation of exercise programmes in head and neck cancer (HaNC) have been limited. The main aim of the present study is to investigate the feasibility and acceptability of introducing a remotely delivered, fully personalised, collaborative, and flexible approach to prescribing and delivering exercise programmes into the HaNC usual care pathway.

METHODS

This is a single arm, feasibility study. Seventy patients diagnosed with HaNC will be recruited from two regional HaNC centres in the United Kingdom. Patients will undertake an 8-week exercise programme designed and delivered by cancer exercise specialists. The exercise programme will start any time between the time of diagnosis and up to 8 weeks after completing treatment, depending on patient preference. The content of the exercise programme will be primarily based on patient needs, preferences, and goals, but guided by current physical activity guidelines for people with cancer. The primary outcome measure is retention to the study. Secondary quantitative outcomes are uptake to the exercise programme, different measures of exercise adherence, pre- and post-intervention assessments of fatigue (Multidimensional Fatigue Symptom Inventory-Short Form), quality of life (SF-36), physical activity levels (International Physical Activity Questionnaire-Short Form), and various components of physical fitness. The outcomes of the nested qualitative study are acceptability and feasibility of the intervention evaluated via interviews with patients, health care professionals, and the cancer exercise specialists. Intervention and participant fidelity will be determined using checklists and scrutiny of each patient's logbook and the cancer exercise specialists' meeting notes. Analysis of quantitative data will be via standard summary statistics. Qualitative data will be analysed using thematic analysis.

EXPECTED RESULTS

This feasibility study will inform the design and conduct of a future randomised controlled trial. Success will be defined according to a traffic light system for identifying the appropriateness of progression to a randomised controlled trial.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number registry (ISRCTN82505455).

Barriers to and facilitators of physical activity in adults living with and beyond cancer, with special emphasis on head and neck cancer: a systematic review of qualitative and mixed methods studies

PURPOSE

Physical activity can improve health outcomes for cancer patients; however, only 30% of patients are physically active. This review explored barriers to and facilitators of physical activity promotion and participation in patients living with and beyond cancer. Secondary aims were to (1) explore similarities and differences in barriers and facilitators experienced in head and neck cancer versus other cancers, and (2) identify how many studies considered the influence of socioeconomic characteristics on physical activity behaviour.

METHODS

CINAHL Plus, MEDLINE, PsycINFO, Scopus and Cochrane (CDSR) were searched for qualitative and mixed methods evidence. Quality assessment was conducted using the Mixed Methods Appraisal Tool and a Critical Appraisal Skills Programme Tool. Thematic synthesis and frequency of reporting were conducted, and results were structured using the Capability-Opportunity-Motivation-Behaviour model and Theoretical Domains Framework.

RESULTS

Thirty qualitative and six mixed methods studies were included. Socioeconomic characteristics were not frequently assessed across the included studies. Barriers included side effects and comorbidities (physical capability; skills) and lack of knowledge (psychological capability; knowledge). Having a dry mouth or throat and choking concerns were reported in head and neck cancer, but not across other cancers. Facilitators included improving education (psychological capability; knowledge) on the benefits and safety of physical activity.

CONCLUSION

Educating patients and healthcare professionals on the benefits and safety of physical activity may facilitate promotion, uptakeand adherence. Head and neck cancer patients experienced barriers not cited across other cancers, and research exploring physical activity promotion in this patient group is required to improve physical activity engagement.

Safety and Feasibility of Cardiopulmonary Exercise Testing in Head and Neck Cancer Survivors

PURPOSE

Assess safety and feasibility of the cardiopulmonary exercise test (CPET) for evaluating head and neck cancer (HaNC) survivors. Also compare their cardiorespiratory fitness to age and sex-matched norms and establish current physical activity levels.

METHODS

Fifty HaNC survivors [29 male; mean (SD) age, 62 (8) years], who had completed treatment up to 1 year previously, were recruited. Participants performed a CPET on a cycle ergometer to symptom-limited tolerance. Participants completed a questionnaire to report contributory factors they perceived as influencing test termination. Physical activity levels were determined using a self-reported physical activity questionnaire.

RESULTS

Three participants did not complete the CPET because (1) poor fitting mouthpiece and naso-oral mask due to facial disfiguration from surgery; (2) knee pain elicited by cycling; and (3) early CPET termination due to electrocardiogram artefacts. Participants reached a mean peak oxygen uptake that was 34% lower than predicted and the mean (SD) CPET duration of 7:52 (2:29) min:s was significantly lower than the target test duration of 10 min (p < 0.001). Leg muscle aches and/or breathing discomfort were major contributory factors influencing test termination for 78% of participants, compared to 13% for dry mouth/throat and/or drainage in the mouth/throat. No major adverse events occurred. Participants were categorised as 26% active, 8% moderately active, and 66% insufficiently active.

CONCLUSION

These preliminary data suggest the CPET appears safe and feasible for most HaNC survivors when strict exclusion criteria are applied; however, low levels of cardiorespiratory fitness should be considered when calculating an appropriate ramp rate.

Acute effects of mixed circuit training on hemodynamic and cardiac autonomic control in chronic hemiparetic stroke patients: A randomized controlled crossover trial

Objectives: To investigate whether a single bout of mixed circuit training (MCT) can elicit acute blood pressure (BP) reduction in chronic hemiparetic stroke patients, a phenomenon also known as post-exercise hypotension (PEH).

Methods: Seven participants (58 ± 12 years) performed a non-exercise control session (CTL) and a single bout of MCT on separate days and in a randomized counterbalanced order. The MCT included 10 exercises with 3 sets of 15-repetition maximum per exercise, with each set interspersed with 45 s of walking. Systolic (SBP) and diastolic (DBP) blood pressure, mean arterial pressure (MAP), cardiac output (Q), systemic vascular resistance (SVR), baroreflex sensitivity (BRS), and heart rate variability (HRV) were assessed 10 min before and 40 min after CTL and MCT. BP and HRV were also measured during an ambulatory 24-h recovery period.

Results: Compared to CTL, SBP (∆-22%), DBP (∆-28%), SVR (∆-43%), BRS (∆-63%), and parasympathetic activity (HF; high-frequency component: ∆-63%) were reduced during 40 min post-MCT (p < 0.05), while Q (∆35%), sympathetic activity (LF; low-frequency component: ∆139%) and sympathovagal balance (LF:HF ratio: ∆145%) were higher (p < 0.001). In the first 10 h of ambulatory assessment, SBP (∆-7%), MAP (∆-6%), and HF (∆-26%) remained lowered, and LF (∆11%) and LF:HF ratio (∆13%) remained elevated post-MCT vs. CTL (p < 0.05).

Conclusion: A single bout of MCT elicited prolonged PEH in chronic hemiparetic stroke patients. This occurred concurrently with increased sympathovagal balance and lowered SVR, suggesting vasodilation capacity is a major determinant of PEH in these patients. This clinical trial was registered in the Brazilian Clinical Trials Registry (RBR-5dn5zd), available at https://ensaiosclinicos.gov.br/rg/RBR-5dn5zd.

Clinical Trial Registration:https://ensaiosclinicos.gov.br/rg/RBR-5dn5zd, identifier RBR-5dn5zd

Using Behavior Change Interventions in Cardiac and Pulmonary Rehabilitation: Perspectives from Healthcare Professionals in the United Kingdom

This study explores healthcare professionals’ experiences of using behavior change interventions in clinical practice. Semi-structured qualitative interviews were conducted with 11 healthcare professionals working in a cardiac and pulmonary rehabilitation National Health Service Trust in the United Kingdom. Interviews were transcribed and analyzed using inductive thematic analysis. Four overarching themes representing healthcare practitioners’ perceptions of using behavior change interventions were identified: (1) reliance on experiential learning, (2) knowledge transition, (3) existing professional development programs, and (4) barriers and facilitators for continued professional development. The results are discussed in relation to the implications they may have for behavior change training in clinical healthcare practice. Healthcare professionals require bespoke and formalized training to optimize their delivery of behavior change interventions in cardiac and pulmonary rehabilitation. Doing so will enhance intervention fidelity and implementation that can potentially ameliorate patient rehabilitation outcomes.

Appetite and energy intake following a bout of circuit resistance training in chronic hemiparetic stroke patients: a preliminary randomized controlled trial

PURPOSE

The main aim of this study was to investigate the effects of circuit resistance training (CRT) on post-exercise appetite and energy intake in chronic hemiparetic stroke patients. A secondary aim was to evaluate the reproducibility of these effects.

METHODS

Seven participants met the eligibility criteria and, in a randomized order, participated in a non-exercise control session (CTL) and two bouts of CRT. The CRT involved 10 exercises with 3 sets of 15-repetition maximum per exercise, performed using a vertical loading approach, with each set interspersed with 45s of walking. Expired gases were carried out   to calculate the net energy cost of the exercise and the relative energy intake post-CTL/CRT. Hunger, fullness, desire to eat, and energy intake were assessed at baseline and for 12 h after CTL and CRT.

RESULTS

Compared to CTL, hunger, desire to eat (P < .001), and relative energy intake (P < .05) were significantly lower after CRT, whereas the perception of fullness was significantly higher (P < .001). Significant differences between CTL and CRT were observed only for the first 9 h of the post-exercise period for hunger, fullness, and desire to eat (P < .05). No significant differences in appetite or relative energy intake were observed between the two bouts of CRT.

CONCLUSIONS

A bout of CRT elicited decreased post-exercise appetite and relative energy intake in chronic hemiparetic stroke patients. Decreased appetite perceptions lasted for around 9 h and were reproducible.

Patients' views of physical activity whilst living with and beyond head and neck cancer

Exercise is an important component of recovery following cancer. Head and neck cancer (HNC) patients typically report low levels of engagement in exercise initiatives. The aim of this study was to give insight into HNC patients' reflections on how and why they would be interested in participating in an exercise programme. A stratified sample of 51 patients based on age, gender and initial interest in an exercise programme was selected from 430 postal survey respondents. Twenty-five took part in a semi-structured telephone interview. There was responder bias with females, younger patients, and those already participating in or interested in an exercise programme being over-represented. The responders in this study highlighted issues related to physical activity levels, perceived ability to meet physical activity guidelines for cancer survivors, perceived exercise benefits, perceived exercise barriers, and advice to others diagnosed with cancer. The findings support the premise of personalized interventions tailored towards the specific needs of the patient, supported by patient peers to emphasize the benefits and help motivate patients to take part. In order to promote engagement in exercise there needs to be collaborative, culturally sensitive and individualized approaches, in order to address the specific barriers experienced by HNC patients.

Is a verification phase useful for confirming maximal oxygen uptake in apparently healthy adults? A systematic review and meta-analysis

BACKGROUND

The 'verification phase' has emerged as a supplementary procedure to traditional maximal oxygen uptake (VO2max) criteria to confirm that the highest possible VO2 has been attained during a cardiopulmonary exercise test (CPET).

OBJECTIVE

To compare the highest VO2 responses observed in different verification phase procedures with their preceding CPET for confirmation that VO2max was likely attained.

METHODS

MEDLINE (accessed through PubMed), Web of Science, SPORTDiscus, and Cochrane (accessed through Wiley) were searched for relevant studies that involved apparently healthy adults, VO2max determination by indirect calorimetry, and a CPET on a cycle ergometer or treadmill that incorporated an appended verification phase. RevMan 5.3 software was used to analyze the pooled effect of the CPET and verification phase on the highest mean VO2. Meta-analysis effect size calculations incorporated random-effects assumptions due to the diversity of experimental protocols employed. I2 was calculated to determine the heterogeneity of VO2 responses, and a funnel plot was used to check the risk of bias, within the mean VO2 responses from the primary studies. Subgroup analyses were used to test the moderator effects of sex, cardiorespiratory fitness, exercise modality, CPET protocol, and verification phase protocol.

RESULTS

Eighty studies were included in the systematic review (total sample of 1,680 participants; 473 women; age 19-68 yr.; VO2max 3.3 ± 1.4 L/min or 46.9 ± 12.1 mL·kg-1·min-1). The highest mean VO2 values attained in the CPET and verification phase were similar in the 54 studies that were meta-analyzed (mean difference = 0.03 [95% CI = -0.01 to 0.06] L/min, P = 0.15). Furthermore, the difference between the CPET and verification phase was not affected by any of the potential moderators such as verification phase intensity (P = 0.11), type of recovery utilized (P = 0.36), VO2max verification criterion adoption (P = 0.29), same or alternate day verification procedure (P = 0.21), verification-phase duration (P = 0.35), or even according to sex, cardiorespiratory fitness level, exercise modality, and CPET protocol (P = 0.18 to P = 0.71). The funnel plot indicated that there was no significant publication bias.

CONCLUSIONS

The verification phase seems a robust procedure to confirm that the highest possible VO2 has been attained during a ramp or continuous step-incremented CPET. However, given the high concordance between the highest mean VO2 achieved in the CPET and verification phase, findings from the current study would question its necessity in all testing circumstances.

PROSPERO REGISTRATION ID

CRD42019123540.

Postexercise hypotension and related hemodynamic responses to cycling under heat stress in untrained men with elevated blood pressure

PURPOSE

To investigate the effect of heat stress on postexercise hypotension.

METHODS

Seven untrained men, aged 21-33 years, performed two cycling bouts at 60% of oxygen uptake reserve expending 300 kcal in environmental temperatures of 21 °C (TEMP) and 35 °C (HOT) in a randomized, counter-balanced order. Physiological responses were monitored for 10-min before and 60-min after each exercise bout, and after a non-exercise control session (CON). Blood pressure (BP) also was measured during the subsequent 21-h recovery period.

RESULTS

Compared to CON, systolic, and diastolic BPs were significantly reduced in HOT (Δ = - 8.3 ± 1.6 and - 9.7 ± 1.4 mmHg, P < 0.01) and TEMP (Δ = - 4.9 ± 2.1 and - 4.5 ± 0.9 mmHg, P < 0.05) during the first 60 min of postexercise recovery. Compared to TEMP, rectal temperature was 0.6 °C higher (P = 0.001), mean skin temperature was 1.8 °C higher (P = 0.013), and plasma volume (PV) was 2.6 percentage points lower (P = 0.005) in HOT. During the subsequent 21-h recovery period systolic BP was 4.2 mmHg lower in HOT compared to CON (P = 0.016) and 2.5 mmHg lower in HOT compared to TEMP (P = 0.039).

CONCLUSION

Exercise in the heat increases the hypotensive effects of exercise for at least 22 h in untrained men with elevated blood pressure. Our findings indicate that augmented core and skin temperatures and decreased PV are the main hemodynamic mechanisms underlying a reduction in BP after exercise performed under heat stress.

Continuous and Accumulated Bouts of Cycling Matched by Intensity and Energy Expenditure Elicit Similar Acute Blood Pressure Reductions in Prehypertensive Men

Fonseca, GF, Farinatti, PTV, Midgley, AW, Ferreira, A, de Paula, T, Monteiro, WD, and Cunha, FA. Continuous and accumulated bouts of cycling matched by intensity and energy expenditure elicit similar acute blood pressure reductions in prehypertensive men. J Strength Cond Res 32(3): 857-866, 2018-This study investigated differences in postexercise hypotension (PEH) after continuous vs. accumulated isocaloric bouts of cycling. Ten prehypertensive men, aged 23-34 years, performed 2 bouts of cycling at 75% oxygen uptake reserve, with total energy expenditures of 400 kcal per bout. One exercise bout was performed continuously (CONTIN) and the other as 2 smaller bouts each expending 200 kcal (INTER1 and INTER2). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and cardiac autonomic control were monitored in a supine position for 10 minutes before and 60 minutes after each exercise bout, and during a control session. Compared with control, blood pressure was significantly reduced after CONTIN (SBP: [INCREMENT] - 3.4 mm Hg, p < 0.001; MAP: [INCREMENT] - 2.5 mm Hg, p = 0.001), INTER1 (SBP: [INCREMENT] - 2.2 mm Hg, p = 0.045), and INTER2 (SBP: [INCREMENT] - 4.4 mm Hg, p < 0.001; DBP: [INCREMENT] - 2.7 mm Hg, p = 0.045; MAP: [INCREMENT] - 3.3 mm Hg, p = 0.001). The PEH was similar in CONTIN and INTER2, whereas INTER2 elicited greater PEH than INTER1 (SBP and MAP: [INCREMENT] - 2.0 and [INCREMENT] - 1.8 mm Hg, respectively, p ≤ 0.05). Increases in sympathovagal balance from baseline were inversely related to changes in SBP and DBP after CONTIN and INTER2 (r = -0.64 to -0.71; p = 0.021-0.047). These findings indicate that similar amounts of PEH are observed when exercise is performed as a single 400-kcal exercise bout or 2 × 200-kcal bouts and that the exercise recovery pattern of cardiac autonomic activity may be important in eliciting PEH.

An intervention for pulmonary rehabilitators to develop a social identity for patients attending exercise rehabilitation: a feasibility and pilot randomised control trial protocol

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a degenerative condition that can impair health-related quality of life (HRQoL). A number of self-management interventions, employing a variety of behavioural change techniques (BCTs), have been adopted to improve HRQoL for COPD patients. However, a lack of attention has been given to group management interventions with an emphasis on incorporating BCTs into rehabilitators' practice. This study aims to pilot and feasibly explore a social identity group management intervention, delivered by COPD rehabilitation staff to patients attending exercise pulmonary rehabilitation. Doing so will help inform the plausibility of the intervention before conducting a full trial to evaluate its effectiveness to improve HRQoL.

METHODS

This is a two-centre, randomised cross-over controlled trial. Two pulmonary rehabilitation centres based in the UK will be randomly allocated to two treatment arms (standard care and intervention). Outcome measurements relating to HRQoL and social identity will be completed pre- and post-exercise rehabilitation. Focus group interviews will be conducted at the end of exercise rehabilitation to capture participants' contextualised experiences of the intervention. COPD rehabilitators will undertake semi-structured interviews at the end of the trial to garner their holistic perspectives of intervention fidelity and implementation.

DISCUSSION

This is the first study to adopt a social identity approach to develop a rehabilitator-led, group management intervention for COPD patients attending exercise pulmonary rehabilitation. The results of this study will provide evidence for the feasibility and sample size requirements to inform a larger study, which can ascertain the intervention's effectiveness for improving HRQoL for COPD patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02288039. Date 31 October 2014.

Exercise program design considerations for head and neck cancer survivors

The present study aimed to establish exercise preferences, barriers, and perceived benefits among head and neck cancer survivors, as well as their level of interest in participating in an exercise program. Patients treated for primary squamous cell carcinoma of the head and neck between 2010 and 2014 were identified from the hospital database and sent a postal questionnaire pack to establish exercise preferences, barriers, perceived benefits, current physical activity levels, and quality of life. A postal reminder was sent to non-responders 4 weeks later. The survey comprised 1021 eligible patients of which 437 (43%) responded [74% male, median (interquartile range) age, 66 (60-73) years]. Of the respondents, 30% said 'Yes' they would be interested in participating in an exercise program and 34% said 'Maybe'. The most common exercise preferences were a frequency of three times per week, moderate-intensity, and 15-29 min per bout. The most popular exercise types were walking (68%), flexibility exercises (35%), water activites/swimming (33%), cycling (31%), and weight machines (19%). Home (55%), outdoors (46%) and health club/gym (33%) were the most common preferred choices for where to regularly exercise. Percieved exercise benefits relating to improved physical attributes were commonly cited, whereas potential social and work-related benefits were less well-acknowledged. The most commonly cited exercise barriers were dry mouth or throat (40%), fatigue (37%), shortness of breath (30%), muscle weakness (28%) difficulty swallowing (25%), and shoulder weakness and pain (24%). The present findings inform the design of exercise programs for head and neck cancer survivors.

Standardized MET Value Underestimates the Energy Cost of Treadmill Running in Men

The main purpose of the present study was to compare the reference metabolic equivalent (MET) value and observed resting oxygen uptake (VO₂) for defining cardiorespiratory fitness (VO_2max) and characterizing the energy cost of treadmill running. A heterogeneous cohort of 114 healthy men volunteered to participate. In Part 1 of the study, 114 men [mean±SD, age: 24±5 years; height: 177.1±7.9 cm; body mass: 75.0±10.0 kg] visited the laboratory twice for assessment of resting and maximal VO₂ values to compare the reference MET value vs. observed resting VO₂ and to investigate the association between resting VO₂ and VO_2max. In Part 2, 14 of the 114 men visited the laboratory once more to perform a 30-min bout of running at 8.0 km∙h^-1/8.3 METs. The mean observed resting VO₂ of 3.26 mL·kg^-1·min^-1 was lower than the reference MET value of 3.5 mL·kg^-1·min^-1 (P<0.001). Resting and maximal VO₂ values relative to total body mass and fat-free mass were positively correlated (R=0.71 and 0.60, respectively; P<0.001). The maximal MET and energy cost of treadmill running were consequently underestimated when calculated using the reference MET value only for those with low VO_2max (P=0.005 to P<0.001). In conclusion, the reference MET value considerably overestimated observed resting VO₂ in men with low VO_2max, resulting in underestimations of the maximal MET, exercise intensity prescription, and the energy cost of running.

A call to action towards an evidence-based approach to using verbal encouragement during maximal exercise testing

By definition, maximal exercise testing inherently requires participants to give a maximal effort. This is an important practical issue as submaximal efforts can produce invalid test results. Verbal encouragement is commonly used to motivate participants to maintain or increase effort investment during maximal exercise testing. Accordingly, studies have reported significant increases in time to exhaustion of between 8% and 18% during VO_2max and multistage shuttle run tests, and a significant 30·5 m mean increase in 6-min walk test distance. Significant improvements during shorter tests, such as the Wingate and 2-min walk tests, have not been observed however. Although participants typically perceive verbal encouragement positively during maximal exercise testing, around one-third have neutral or negative perceptions. Despite the ubiquity and importance of verbal encouragement during maximal exercise testing, surprisingly little research has investigated the characteristics of effective encouragement with respect to its content, timing and frequency. The only randomized controlled trial to investigate one of these issues observed that verbal encouragement delivered every 20 s increased time to exhaustion during VO_{2 max} testing, but not every 60 or 180 s. Of particular concern is that several exercise testing guidelines have incorporated specific guidelines for the use of verbal encouragement, but not provided any theoretical or empirical justification, presumably because of the limited research to inform practice. Recent empirical research does provide some important insight into participant preference for the content and timing of verbal encouragement during maximal exercise testing; however, much more research is clearly required to establish comprehensive evidence-based guidelines.

The Hsp72 and Hsp90α mRNA Responses to Hot Downhill Running Are Reduced Following a Prior Bout of Hot Downhill Running, and Occur Concurrently within Leukocytes and the Vastus Lateralis

The leukocyte heat shock response (HSR) is used to determine individual's thermotolerance. The HSR and thermotolerance are enhanced following interventions such as preconditioning and/or acclimation/acclimatization. However, it is unclear whether the leukocyte HSR is an appropriate surrogate for the HSR in other tissues implicated within the pathophysiology of exertional heat illnesses (e.g., skeletal muscle), and whether an acute preconditioning strategy (e.g., downhill running) can improve subsequent thermotolerance. Physically active, non-heat acclimated participants were split into two groups to investigate the benefits of hot downhill running as preconditioning strategy. A hot preconditioning group (HPC; n = 6) completed two trials (HPC1_HOTDOWN and HPC2_HOTDOWN) of 30 min running at lactate threshold (LT) on -10% gradient in 30°C and 50% relative humidity (RH) separated by 7 d. A temperate preconditioning group (TPC; n = 5) completed 30 min running at LT on a -1% gradient in 20°C and 50% (TPC1_TEMPFLAT) and 7 d later completed 30 min running at LT on -10% gradient in 30°C and 50% RH (TPC2_HOTDOWN). Venous blood samples and muscle biopsies (vastus lateralis; VL) were obtained before, immediately after, 3, 24, and 48 h after each trial. Leukocyte and VL Hsp72, Hsp90α, and Grp78 mRNA relative expression was determined via RT-QPCR. Attenuated leukocyte and VL Hsp72 (2.8 to 1.8 fold and 5.9 to 2.4 fold; p < 0.05) and Hsp90α mRNA (2.9 to 2.4 fold and 5.2 to 2.4 fold; p < 0.05) responses accompanied reductions (p < 0.05) in physiological strain [exercising rectal temperature (-0.3°C) and perceived muscle soreness (~ -14%)] during HPC2_HOTDOWN compared to HPC1_HOTDOWN (i.e., a preconditioning effect). Both VL and leukocyte Hsp72 and Hsp90α mRNA increased (p < 0.05) simultaneously following downhill runs and demonstrated a strong relationship (p < 0.01) of similar magnitudes with one another. Hot downhill running is an effective preconditioning strategy which ameliorates physiological strain, soreness and Hsp72 and Hsp90α mRNA responses to a subsequent bout. Leukocyte and VL analyses are appropriate tissues to infer the extent to which the HSR has been augmented.

Relationship Between Percentages of Heart Rate Reserve and Oxygen Uptake Reserve During Cycling and Running: A Validation Study

Guimarães, GC, Farinatti, PTV, Midgley, AW, Vasconcellos, F, Vigário, P, and Cunha, FA. Relationship between percentages of heart rate reserve and oxygen uptake reserve during cycling and running: a validation study. J Strength Cond Res 33(7): 1954-1962, 2019-This study investigated the relationship between percentages of heart rate reserve (%HRR) and oxygen uptake reserve (%VO2R) during a cardiopulmonary exercise test (CPET) and discrete bouts of isocaloric cycling and treadmill running. Thirty men visited the laboratory 3 times for anthropometrical and resting VO2 assessments, and perform cycling and running CPETs. Ten men visited the laboratory twice more to investigate the validity of the %HRR-%VO2R relationships during isocaloric bouts of cycling and running at 75% VO2R with energy expenditures of 400 kcals. The %HRR was significantly higher than the %VO2R during both CPETs at all exercise intensities (p < 0.001). During isocaloric exercise bouts, mean %HRR-%VO2R differences of 6.5% and 7.0% were observed for cycling and running, respectively (p = 0.007-p < 0.001). The %HRR and %VO2R increased over time (p < 0.001), the rate of which was influenced by exercise modality (p < 0.001). On average, heart rate was 5 (p = 0.007) and 8 (p < 0.001) b·min higher than predicted from the second energy expenditure quartile for cycling and running, respectively; however, observed VO2 was lower than predicted during all quartiles for cycling, and the first quartile for running. Consequently, time to achieve the target energy expenditure was greater than predicted (p < 0.01). In conclusion, the %HRR-%VO2R relationship observed during CPET data did not accurately transpose to prolonged isocaloric bouts of cycling and running. In addition, power outputs and speeds defined by the American College of Sports Medicine equations for cycling and running, respectively, overestimated VO2 and energy expenditure.

A Reduction in Maximal Incremental Exercise Test Duration 48 h Post Downhill Run Is Associated with Muscle Damage Derived Exercise Induced Pain

Purpose: To examine whether exercise induced muscle damage (EIMD) and muscle soreness reduce treadmill maximal incremental exercise (MIE) test duration, and true maximal physiological performance as a consequence of exercise induced pain (EIP) and perceived effort.

Methods: Fifty (14 female), apparently healthy participants randomly allocated into a control group (CON, n = 10), or experimental group (EXP, n = 40) visited the laboratory a total of six times: visit 1 (familiarization), visit 2 (pre 1), visit 3 (pre 2), visit 4 (intervention), visit 5 (24 h post) and visit 6 (48 h post). Both groups performed identical testing during all visits, except during visit 4, where only EXP performed a 30 min downhill run and CON performed no exercise. During visits 2, 3, and 6 all participants performed MIE, and the following measurements were obtained: time to exhaustion (TTE), EIP, maximal oxygen consumption (V·O2max), rate of perceived exertion (RPE), maximum heart rate (HR_max), maximum blood lactate (BLa_max), and the contribution of pain to terminating the MIE (assessed using a questionnaire). Additionally during visits 1, 2, 3, 5, and 6 the following markers of EIMD were obtained: muscle soreness, maximum voluntary contraction (MVC), voluntary activation (VA), creatine kinase (CK).

Results: There were no significant differences (p ≥ 0.32) between any trials for any of the measures obtained during MIE for CON. In EXP, TTE decreased by 34 s (3%), from pre 2 to 48 h post (p < 0.001). There was a significant association between group (EXP, CON) and termination of the MIE due to “pain” during 48 h post (χ² = 14.7, p = 0.002).

Conclusion: EIMD resulted in premature termination of a MIE test (decreased TTE), which was associated with EIP, MVC, and VA. The exact mechanisms responsible for this require further investigation.

Deceptive Manipulation of Competitive Starting Strategies Influences Subsequent Pacing, Physiological Status, and Perceptual Responses during Cycling Time Trials

Little is currently known regarding competitor influence on pacing at the start of an event and in particular the subsequent effect on the remaining distance. The purpose of the present study was to investigate the influence of starting pace on the physiological and psychological responses during cycling time trials (TT) utilizing an innovative approach allowing pace to be accurately and dynamically replicated, as well as deceptively manipulated. Ten competitive male cyclists completed five 16.1 km TT, two baseline trials performed alone (BLs), and three with a simulated, dynamic avatar of which they were to match the pace of for the initial 4 km. The avatar represented either the cyclist's fastest BL performance (NORM), 105% (FAST), or 95% (SLOW), of fastest BL performance (FBL). Physiological and psychological responses were measured every quartile of the TT. Despite manipulating a starting speed of ± 5% of fastest previous performance, there was no effect on overall 16.1 km TT performance. Manipulated starting strategies did however evoke different physiological and perceptual responses. Whole trial differences found that SLOW produced lower HR, VO₂, BLa and RPE than FBL (p ≤ 0.03) and higher SE than FAST (p ≤ 0.03). Additionally, FAST had greater internal attention than NORM (p < 0.04). Over time all psychological and physiological variables had a significant condition × quartile interaction in the initial or second quartile mediated by the prescribed starting strategies. Furthermore, RPE, affect, and internal attention remained elevated throughout FAST despite an attenuation in pace during self-selection of pace. There were no differences in performance time when manipulating a 16.1 km cycling TT starting strategy. A slow start, encouraged greater positive perceptions, and less negative physiological consequences than a faster start, and produces no impairment to performance time. It would therefore be considered an advantage in a non-drafting event, not to follow pace of fellow, superior competitors at the start of an event but perform a more negative pacing strategy, with the potential for a greater speed increase against opponents in the latter stages.

Improvements in Cycling Time Trial Performance Are Not Sustained Following the Acute Provision of Challenging and Deceptive Feedback

The provision of performance-related feedback during exercise is acknowledged as an influential external cue used to inform pacing decisions. The provision of this feedback in a challenging or deceptive context allows research to explore how feedback can be used to improve performance and influence perceptual responses. However, the effects of deception on both acute and residual responses have yet to be explored, despite potential application for performance enhancement. Therefore, this study investigated the effects of challenging and deceptive feedback on perceptual responses and performance in self-paced cycling time trials (TT) and explored whether changes in performance are sustained in a subsequent TT following the disclosure of the deception. Seventeen trained male cyclists were assigned to either an accurate or deceptive feedback group and performed four 16.1 km cycling TTs; (1 and 2) ride-alone baseline TTs where a fastest baseline (FBL) performance was identified, (3) a TT against a virtual avatar representing 102% of their FBL performance (PACER), and (4) a subsequent ride-alone TT (SUB). The deception group, however, were initially informed that the avatar accurately represented their FBL, but prior to SUB were correctly informed of the nature of the avatar. Affect, self-efficacy and RPE were measured every quartile. Both groups performed PACER faster than FBL and SUB (p < 0.05) and experienced lower affect (p = 0.016), lower self-efficacy (p = 0.011), and higher RPE (p < 0.001) in PACER than FBL. No significant differences were found between FBL and SUB for any variable. The presence of the pacer rather than the manipulation of performance beliefs acutely facilitates TT performance and perceptual responses. Revealing that athletes' performance beliefs were falsely negative due to deceptive feedback provision has no effect on subsequent perceptions or performance. A single experiential exposure may not be sufficient to produce meaningful changes in the performance beliefs of trained individuals beyond the acute setting.

Acute Hypotensive Response to Continuous and Accumulated Isocaloric Aerobic Bouts

Evidence indicates that chronic reductions in blood pressure (BP) due to aerobic exercise depend on the ability to induce post-exercise hypotension (PEH) after each training bout. The purpose of this study was to investigate PEH after isocaloric bouts of continuous and accumulated running. 10 healthy pre-hypertensive men (aged 27.6±3.5 years) performed the following bouts of exercise: a) A continuous bout (CONT) expending a total of 400 kcal; and b) An accumulated bout split into 2×200 kcal (INTER1 and INTER2) to total 400 kcal at 75% of oxygen uptake reserve. BP, mean arterial pressure (MAP) and heart rate variability were monitored 10 min before and 60 min after control and all exercise conditions. The decrease in MAP over time after continuous (400 kcal) and accumulated (2×200 kcal) bouts of exercise was more pronounced than during control (mean diff between 1.6 and 5.4 mmHg, P≤0.01), although the magnitude of change was similar between continuous and accumulated bouts (mean diff=0.1 mmHg, P=0.79). Concomitant to the PEH, sympathovagal balance was inversely related to changes in MAP after isocaloric bouts performed continuously and cumulatively (r=- 0.72 and-0.85, P=0.019 and 0.002, respectively). In conclusion, BP decreased to similar levels after continuous and accumulated acute aerobic exercise matched for total energy expenditure. Our findings also indicate that the recovery pattern of cardiac autonomic activity may have an important role in eliciting PEH.

Effective microorganism - X attenuates circulating superoxide dismutase following an acute bout of intermittent running in hot, humid conditions

This study determined the effectiveness of antioxidant supplementation on high-intensity exercise-heat stress. Six males completed a high-intensity running protocol twice in temperate conditions (TEMP; 20.4°C), and twice in hot conditions (HOT; 34.7°C). Trials were completed following7 days supplementation with 70 ml·day(-1) effective microorganism-X (EM-X; TEMPEMX or HOTEMX) or placebo (TEMPPLA or HOTPLA). Plasma extracellular Hsp72 (eHsp72) and superoxide dismutase (SOD) were measured by ELISA. eHsp72 and SOD increased pre-post exercise (p < 0.001), with greater eHsp72 (p < 0.001) increases observed in HOT (+1.5 ng·ml(-1)) compared to TEMP (+0.8 ng·ml(-1)). EM-X did not influence eHsp72 (p > 0.05). Greater (p < 0.001) SOD increases were observed in HOT (+0.22 U·ml(-1)) versus TEMP (+0.10 U·ml(-1)) with SOD reduced in HOTEMX versus HOTPLA (p = 0.001). Physiological and perceptual responses were all greater (p < 0.001) in HOT versus TEMP conditions, with no difference followed EM-X (p > 0.05). EM-X supplementation attenuated the SOD increases following HOT, potentiating its application as an ergogenic aid to ameliorate oxidative stress.

Deception has no acute or residual effect on cycling time trial performance but negatively effects perceptual responses

OBJECTIVES

Feedback deception is used to explore the importance of expectations on pacing strategy and performance in self-paced exercise. The deception of feedback from a previous performance explores the importance of experience knowledge on exercise behaviour. This study aimed to explore the acute and residual effects of the deception of previous performance speed on perceptual responses and performance in cycling time trials.

DESIGN

A parallel-group design.

METHODS

Twenty cyclists were assigned to a control or deception group and performed 16.1km time trials. Following a ride-alone baseline time trial (FBL), participants performed against a virtual avatar representing their FBL performance (PACER), then completed a subsequent ride-alone time trial (SUB). The avatar in the deception group, however, was unknowingly set 2% faster than their FBL.

RESULTS

Both groups performed faster in PACER than FBL and SUB (p<0.05), but SUB was not significantly different to FBL. Affect was more negative and Ratings of Perceived Exertion (RPE) were higher in PACER than FBL in the deception group (p<0.05).

CONCLUSIONS

The presence of a visual pacer acutely facilitated time trial performance, but deceptive feedback had no additional effect on performance. The deception group, however, experienced more negative affect and higher RPE in PACER, whereas these responses were absent in the control group. The performance improvement was not sustained in SUB, suggesting no residual performance effects occurred.

The effect of different environmental conditions on the decision-making performance of soccer goal line officials

Goal line officials (GLO) are exposed to extreme environmental conditions when employed to officiate in professional European soccer cup competitions. The present study aimed to investigate the effect of such environments on GLO decision-making ability. Thirteen male participants were exposed to three conditions: cold (-5°C, 50% relative humidity (RH)); temperate (18°C, 50% RH); and hot (30°C, 50% RH) for 90 min per condition, with a 15 min half-time break after 45 min. Decision-making ability was assessed throughout the 90 min exposure. Core and skin temperatures were recorded throughout. Decision making was improved during exposure to the temperate condition when compared with the cold (mean difference = 12.5%; 95% CI = 1.1%, 23.9%; P = 0.031). Regression analysis indicated that as skin temperature increases so does decision-making ability. Exposure to cold conditions diminished the decision-making ability of GLO.

Postexercise hypotension after maximal short-term incremental exercise depends on exercise modality

This study investigated postexercise hypotension (PEH) after maximal cardiopulmonary exercise testing (CPET) performed using different exercise modalities. Twenty healthy men (aged 23 ± 3 years) performed 3 maximal CPETs (cycling, walking, and running), separated by 72 h in a randomized, counter-balanced order. Systolic (SBP) and diastolic blood pressure (DBP), heart rate, cardiac output, systemic vascular resistance (SVR), autonomic function (spontaneous baroreflex sensitivity (BRS) and heart rate variability (HRV)), and energy expenditure (EE) were assessed during a 60-min nonexercise control session and for 60 min immediately after each CPET. Total exercise volume (EE during CPET plus 60 min recovery) was significantly higher in running versus cycling and walking CPETs (P ≤ 0.001). Compared with control, only SBP after running CPET was significantly reduced (Δ = −6 ± 8 mm Hg; P < 0.001). Heart rate and cardiac output were significantly increased (P < 0.001) and SVR significantly decreased (P < 0.001) postexercise. BRS and HRV decreased after all CPETs (P < 0.001), whereas sympatho-vagal balance (low- and high-frequency (LF:HF) ratio) increased significantly after all exercise conditions, especially after running CPET (P < 0.001). Changes in SVR, BRS, sympathetic activity (low-frequency component of HRV), and LF:HF ratio were negatively correlated to variations in SBP (range −0.69 to −0.91; P < 0.001) and DBP (range −0.58 to −0.93; P ≤ 0.002). These findings suggest that exercise mode or the total exercise volume are major determinants of PEH magnitude in healthy men. Because of the running CPET, the PEH was primarily related to a decrease in SVR and to an increase in sympatho-vagal balance, which might be a reflex response to peripheral vasodilatation after exercise.

Altered Psychological Responses to Different Magnitudes of Deception during Cycling

PURPOSE

Deceptive manipulations of performance intensity have previously been investigated in cycling time trials (TT) but used different magnitudes, methods, and task durations. This study examines previously used magnitudes of deception during 16.1-km TT and explores yet unexamined psychological responses.

METHODS

Twelve trained cyclists completed five TT, performing two baseline trials alone, one against a simulated dynamic avatar representing 102% of fastest baseline trial (TT(102%)), one against a 105% avatar (TT(105%)), and one against both avatars (TT(102%,105%)).

RESULTS

Deceptive use of competitors to disguise intensity manipulation enabled accomplishment of performance improvements greater than their perceived maximal (1.3%-1.7%). Despite a similar improvement in performance, during TT(102%,105%), there was significantly lower affect and self-efficacy to continue pace than those during TT(105%) (P < 0.05), significantly lower self-efficacy to compete than that during TT(102%) (P = 0.004), and greater RPE than that during TTFBL (P < 0.001).

CONCLUSIONS

Because the interpretation of performance information and perceptions depends on the manner in which it is presented, i.e., "framing effect," it could be suggested that the summative effect of two opponents could have evoked negative perceptions despite eliciting a similar performance. Magnitudes of deception produce similar performance enhancement yet elicit diverse psychological responses mediated by the external competitive environment the participants were performing in.

Parasympathetic reactivation after maximal CPET depends on exercise modality and resting vagal activity in healthy men

Purpose

The main purpose of this study was to investigate parasympathetic reactivation of the heart [evaluated through heart rate recovery (HRR) and HR variability (HRV)] after maximal cardiopulmonary exercise testing (CPET) using three different exercise modalities.

Methods

Twenty healthy men, aged 17 to 28 yr, performed three maximal CPETs (cycling, walking, and running) separated by 72 h and in a randomized, counter-balanced order. HRR was determined from the absolute differences between HR_peak and HR at 1–3 min after exercise. The root mean square of successive R-R differences calculated for consecutive 30-s windows (rMSSD_30s) was calculated to assess the parasympathetic reactivation after maximal CPET.

Results

Lower HR_peak, VO_2peak and energy expenditure were observed after the cycling CPET than the walking and running CPETs (P < 0.001). Both HRR and rMSSD_30s were significantly greater during recovery from the cycling CPET compared to the walking and running CPETs (P < 0.001). Furthermore, Δ rMSSD (i.e. resting minus postexercise rMSSD every 30 s into the recovery period) was positively related to the resting high-frequency component (HF), rMSSD, and standard deviation of all normal R-R intervals (SDNN) (r_s = 0.89 to 0.98; P < 0.001), and negatively related to the resting low-frequency component (LF) and sympathovagal balance (LF:HF ratio) after all exercise conditions (r_s = −0.73 to −0.79 and −0.86 to −0.90, respectively; P < 0.001).

Conclusions

These findings support that parasympathetic reactivation after maximal CPET (as assessed by HRR and rMSSD_30s) depends on exercise modality and cardiac autonomic control at rest.

Downhill running and exercise in hot environments increase leukocyte Hsp72 (HSPA1A) and Hsp90α (HSPC1) gene transcripts

Stressors within humans and other species activate Hsp72 and Hsp90α mRNA transcription, although it is unclear which environmental temperature or treadmill gradient induces the largest increase. To determine the optimal stressor for priming the Hsp system, physically active but not heat-acclimated participants (19.8 ± 1.9 and 20.9 ± 3.6 yr) exercised at lactate threshold in either temperate (20°C, 50% relative humidity; RH) or hot (30°C, 50% RH) environmental conditions. Within each condition, participants completed a flat running (temperate flat or hot flat) and a downhill running (temperate downhill or hot downhill) experimental trial in a randomized counterbalanced order separated by at least 7 days. Venous blood samples were taken immediately before (basal), immediately after exercise, and 3 and 24 h postexercise. RNA was extracted from leukocytes and RT-quantitative PCR conducted to determine Hsp72 and Hsp90α mRNA relative expression. Leukocyte Hsp72 mRNA was increased immediately after exercise following downhill running (1.9 ± 0.9-fold) compared with flat running (1.3 ± 0.4-fold; P = 0.001) and in hot (1.9 ± 0.6-fold) compared with temperate conditions (1.1 ± 0.5-fold; P = 0.003). Leukocyte Hsp90α mRNA increased immediately after exercise following downhill running (1.4 ± 0.8-fold) compared with flat running (0.9 ± 0.6-fold; P = 0.002) and in hot (1.6 ± 1.0-fold) compared with temperate conditions (0.9 ± 0.6-fold; P = 0.003). Downhill running and exercise in hot conditions induced the largest stimuli for leukocyte Hsp72 and Hsp90α mRNA increases.

Effect of continuous and intermittent bouts of isocaloric cycling and running exercise on excess postexercise oxygen consumption

OBJECTIVES

The purpose of this study was to investigate excess postexercise oxygen consumption (EPOC) induced by isocaloric bouts of continuous and intermittent running and cycling exercise.

DESIGN

This was a counterbalanced randomized cross-over study.

METHODS

Ten healthy men, aged 23-34yr, performed six bouts of exercise: (a) two maximal cardiopulmonary exercise tests for running and cycling to determine exercise modality-specific peak oxygen uptake (VO2peak); and (b) four isocaloric exercise bouts (two continuous bouts expending 400kcal and two intermittent bouts split into 2×200kcal) performed at 75% of the running and cycling oxygen uptake reserve. Exercise bouts were separated by 72h and performed in a randomized, counter-balanced order. The VO2 was monitored for 60-min postexercise and for 60-min during a control non-exercise day.

RESULTS

The VO2 was significantly greater in all exercise conditions compared to the control session (P<0.001). The combined magnitude of the EPOC from the two intermittent bouts was significantly greater than that of the continuous cycling (mean difference=3.5L, P=0.001) and running (mean difference=6.4L, P<0.001). The exercise modality had a significant effect on net EPOC, where running elicited a higher net EPOC than cycling (mean difference=2.2L, P<0.001).

CONCLUSIONS

Intermittent exercise increased the EPOC compared to a continuous exercise bout of equivalent energy expenditure. Furthermore, the magnitude of EPOC was influenced by exercise modality, with the greatest EPOC occurring with isocaloric exercise involving larger muscle mass (i.e., treadmill running vs. cycling).

Competitor presence reduces internal attentional focus and improves 16.1km cycling time trial performance

OBJECTIVES

Whilst the presence of a competitor has been found to improve performance, the mechanisms influencing the change in selected work rates during direct competition have been suggested but not specifically assessed. The aim was to investigate the physiological and psychological influences of a visual avatar competitor during a 16.1-km cycling time trial performance, using trained, competitive cyclists.

DESIGN

Randomised cross-over design.

METHODS

Fifteen male cyclists completed four 16.1km cycling time trials on a cycle ergometer, performing two with a visual display of themselves as a simulated avatar (FAM and SELF), one with no visual display (DO), and one with themselves and an opponent as simulated avatars (COMP). Participants were informed the competitive avatar was a similar ability cyclist but it was actually a representation of their fastest previous performance.

RESULTS

Increased performance times were evident during COMP (27.8±2.0min) compared to SELF (28.7±1.9min) and DO (28.4±2.3min). Greater power output, speed and heart rate were apparent during COMP trial than SELF (p<0.05) and DO (p≤0.06). There were no differences between SELF and DO. Ratings of perceived exertion were unchanged across all conditions. Internal attentional focus was significantly reduced during COMP trial (p<0.05), suggesting reduced focused on internal sensations during an increase in performance.

CONCLUSIONS

Competitive cyclists performed significantly faster during a 16.1-km competitive trial than when performing maximally, without a competitor. The improvement in performance was elicited due to a greater external distraction, deterring perceived exertion.

Influence of exercise modality on agreement between gas exchange and heart rate variability thresholds

The main purpose of this study was to investigate the level of agreement between the gas exchange threshold (GET) and heart rate variability threshold (HRVT) during maximal cardiopulmonary exercise testing (CPET) using three different exercise modalities. A further aim was to establish whether there was a 1:1 relationship between the percentage heart rate reserve (%HRR) and percentage oxygen uptake reserve (%VO2 R) at intensities corresponding to GET and HRVT. Sixteen apparently healthy men 17 to 28 years of age performed three maximal CPETs (cycling, walking, and running). Mean heart rate and VO2 at GET and HRVT were 16 bpm (P<0.001) and 5.2 mL · kg(-1) · min(-1) (P=0.001) higher in running than cycling, but no significant differences were observed between running and walking, or cycling and walking (P>0.05). There was a strong relationship between GET and HRVT, with R2 ranging from 0.69 to 0.90. A 1:1 relationship between %HRR and % VO2 R was not observed at GET and HRVT. The %HRR was higher during cycling (GET mean difference=7%; HRVT mean difference=11%; both P<0.001), walking (GET mean difference=13%; HRVT mean difference=13%; both P<0.001), or running (GET mean difference=11%; HRVT mean difference=10%; both P<0.001). Therefore, using HRVT to prescribe aerobic exercise intensity appears to be valid. However, to assume a 1:1 relationship between %HRR and % VO2 R at HRVT would probably result in overestimation of the energy expenditure during the bout of exercise.

Exploring athletic identity in elite-level English youth football: a cross-sectional approach

This study is the first empirical investigation that has explored levels of athletic identity in elite-level English professional football. The importance of understanding athletes' psychological well-being within professional sport has been well documented. This is especially important within the professional football industry, given the high attrition rate (Anderson, G., & Miller, R. M. (2011). The academy system in English professional football: Business value or following the herd? University of Liverpool, Management School Research Paper Series. Retrieved from http://www.liv.ac.uk/managementschool/research/working%20papers/wp201143.pdf ) and distinct occupational practices (Roderick, M. (2006). The work of professional football. A labour of love? London: Routledge). A total of 168 elite youth footballers from the English professional football leagues completed the Athletic Identity Measurement Scale (AIMS). Multilevel modelling was used to examine the effect of playing level, living arrangements and year of apprentice on the total AIMS score and its subscales (i.e., social identity, exclusivity and negative affectivity). Football club explained 30% of the variance in exclusivity among players (P = .022). Mean social identity was significantly higher for those players in the first year of their apprenticeship compared to the second year (P = .025). All other effects were not statistically significant (P > .05). The novel and unique findings have practical implications in the design and implementation of career support strategies with respect to social identity. This may facilitate the maintenance of motivation over a 2-year apprenticeship and positively impact on performance levels within the professional football environment.

Ramp-incremented and RPE-clamped test protocols elicit similar VO2max values in trained cyclists

PURPOSE

The present study compared the efficacy of ramp incremented and ratings of perceived exertion (RPE)-clamped test protocols for eliciting maximal oxygen uptake (VO2max).

METHODS

Sixteen trained cyclists (age 34 ± 7 years) performed a ramp-incremented protocol and an RPE-clamped protocol 1 week apart in a randomized, counterbalanced order. The RPE-clamped protocol consisted of five, 2-min stages where subjects self-selected work rate and pedal cadence to maintain the prescribed RPE. After completing both test protocols subjects were asked which they preferred.

RESULTS

The mean ± SD test time of 568 ± 72 s in the ramp protocol was not significantly different to the 600 ± 0 s in the RPE-clamped protocol (mean difference = 32 s; p = 0.09), or was the VO2max of 3.86 ± 0.73 L min(-1) in the ramp protocol significantly different to the 3.87 ± 0.72 L min(-1) in the RPE-clamped protocol (mean difference = 0.002 L min(-1); p = 0.97). Furthermore, no significant differences were observed for peak power output (p = 0.21), maximal minute ventilation (p = 0.97), maximal respiratory exchange ratio (p = 0.09), maximal heart rate (p = 0.51), and post-test blood lactate concentration (p = 0.58). The VO2max attained in the preferred protocol was significantly higher than the non-preferred protocol (mean difference = 0.14 L min(-1); p = 0.03).

CONCLUSION

The RPE-clamped test protocol was as effective as the ramp-incremented protocol for eliciting VO2max and could be considered as a valid alternative protocol, particularly where a fixed test duration is desirable.

Warm-up strategies of professional soccer players: practitioners' perspectives

Recent research has challenged the typical pre-match and half-time (HT) interval warm-up (WU) routines currently used by professional soccer players. This study surveyed 2010/11 season WU strategies and their underpinning scientific reasoning and situational factors via an internet-based questionnaire, which was distributed to English Premier League and Championship practitioners, of which 43% responded. The pre-match WU duration was 30.8 (8.2) min, ranging between 15-45 min, and 89% of practitioners administered a WU of ≥ 25 min. Respondents also reported a 12.4 (3.8) min period between the end of the WU and match kick-off. Eighty-nine per cent recognised the physiological benefits of re-WUs during this "down-time" period, with 63% instructing players to engage in such activity. During HT, 58% instructed players to re-WU either on the pitch or within stadia facilities, but "unwillingness of the coach/manager" (42%) and a "lack of time" (63%) were major constraints. Practitioners reported that 2.6 (1.6) min might be available for HT re-WUs. Factors such as match regulations, league policy, and stadia facilities were not generally considered as major barriers to the delivery of WUand re-WU strategies. We suggest that researchers consider the time-demands and barriers faced by practitioners whendeveloping experimental designs to examine WU regimens.

Metabolic equivalent concept in apparently healthy men: a re-examination of the standard oxygen uptake value of 3.5 mL·kg(-1)·min(-1.)

This study compared resting oxygen uptake (V̇O2) with the standard metabolic equivalent (MET) value of 3.5 mL·kg(-1)·min(-1), tested the accuracy of a previously published prediction model for resting V̇O2, and proposed a new prediction model for a more homogeneous population. One hundred and twenty-five apparently healthy men, aged 17-38 years, visited the laboratory for the assessment of resting V̇O2. The mean resting V̇O2 of 3.21 mL·kg(-1)·min(-1) (95% confidence interval (CI), 3.13 to 3.30) was significantly lower than the standard MET value of 3.5 mL·kg(-1)·min(-1) (mean difference, 0.29; 95% CI, 0.20 to 0.37; t = 6.7; p < 0.001). The prediction model proposed by a previous study, derived from a heterogeneous sample, exhibited no predictive ability in our more homogeneous sample. However, our population-specific regression model, which included body surface area and percent body fat as predictors, demonstrated relatively poor predictive ability, with a low R(2) (0.22) and high standard error of the estimate (0.42 mL·kg(-1)·min(-1)). Pearson's correlation coefficients for body surface area and resting V̇O2, and for percent body fat and resting V̇O2, were 0.20 (p = 0.022) and -0.36 (p < 0.001), respectively. In conclusion, the standard MET value of 3.5 mL·kg(-1)·min(-1) considerably overestimates mean resting V̇O2 in a relatively large group of apparently healthy men. Our population-specific prediction model for resting V̇O2 demonstrated relatively poor accuracy, although it was considerably more accurate than the previously published model. Further research needs to be conducted to establish accurate population-specific prediction models.

How long does it take to achieve steady state for an accurate assessment of resting VO₂ in healthy men?

The time necessary to obtain a steady state for an accurate and reliable assessment of resting [Formula: see text] remains unclear and was the purpose of this study. Thirty healthy men, aged 17-28 years, visited the laboratory twice for the assessment of resting [Formula: see text], which was assessed as follows: (a) 24 h abstention from physical exercise, alcohol, soft drinks and caffeine, (b) fasting for at least 8 h, (c) an acclimation period of 10 min, and (d) 60 min assessment in a supine position. Resting [Formula: see text] significantly changed during the 60 min (F = 37.4, P < 0.001), exhibiting a monoexponential decrease before reaching an asymptote. Post hoc pairwise comparisons showed that significant differences existed between consecutive means until the 30 min time point, after which there were no significant differences. The [Formula: see text] response across trials exhibited high test-retest reliability, with within-subject coefficients of variations at each time point ranging from 2.8 to 7.0 % and intraclass correlation coefficients ranging from 0.90 to 0.99. The reliability was higher from the 25 min time point onwards. Based on these findings, the following recommendations are made to promote accurate assessment of resting [Formula: see text]: (a) initiate the resting [Formula: see text] measurement with 10 min of acclimation to the assessment apparatus, (b) determine resting [Formula: see text] for a minimum of 30 min, until an apparent [Formula: see text] steady state has been achieved; and (c) determine resting [Formula: see text] for a further 5 min, with the average of this last 5 min of data being regarding as the resting [Formula: see text].

The effect of the hyperbaric environment on heat shock protein 72 expression in vivo

Heat shock protein 72 (HSP72) is expressed in response to stress and has been demonstrated to follow a diurnal expression pattern within monocytes and is sensitive to changes in core temperature. Numerous studies have shown changes in HSP72 expression within cell lines exposed to hyperbaric conditions. No studies have investigated changes in HSP72 expression in vivo. Six males participated in the study and were exposed to hyperbaric air and hyperbaric oxygen a week apart. Monocyte HSP72 was analyzed by flow cytometry at 09:00, 13:00, 17:00, 21:00 with hyperbaric oxygen or hyperbaric air breathing commencing at 15:00 for 78 min at a pressure of 2.8 ATA. HSP72 under normoxia followed the established trend; however, following the hyperbaric air or oxygen exposure a reduction in detectable HSP72 was observed at 17:00 and 21:00. No changes in core temperature were observed between 13:00 and 21:00 for any condition. The data show that HSP72 expression is impaired following hyperbaric air (HA) exposure, when compared with control or hyperbaric oxygen (HO) exposure.

Hypoxia-mediated prior induction of monocyte-expressed HSP72 and HSP32 provides protection to the disturbances to redox balance associated with human sub-maximal aerobic exercise

HSP72 is rapidly expressed in response to a variety of stressors in vitro and in vivo (including hypoxia). This project sought a hypoxic stimulus to elicit increases in HSP72 and HSP32 in attempts to confer protection to the sub-maximal aerobic exercise-induced disturbances to redox balance. Eight healthy recreationally active male subjects were exposed to five consecutive days of once-daily hypoxia (2,980 m, 75 min). Seven days prior to the hypoxic acclimation period, subjects performed 60 min of cycling on a cycle ergometer (exercise bout 1-EXB1), and this exercise bout was repeated 1 day post-cessation of the hypoxic period (exercise bout 2-EXB2). Blood samples were taken immediately pre- and post-exercise and 1, 4 and 8 h post-exercise for HSP72 and immediately pre, post and 1 h post-exercise for HSP32, TBARS and glutathione [reduced (GSH), oxidised (GSSG) and total (TGSH)], with additional blood samples obtained immediately pre-day 1 and post-day 5 of the hypoxic acclimation period for the same indices. Monocyte-expressed HSP32 and HSP72 were analysed by flow cytometry, with measures of oxidative stress accessed by commercially available kits. There were significant increases in HSP72 (P < 0.001), HSP32 (P = 0.03), GSSG (t = 9.5, P < 0.001) and TBARS (t = 5.6, P = 0.001) in response to the 5-day hypoxic intervention, whereas no significant changes were observed for GSH (P = 0.22) and TGSH (P = 0.25). Exercise-induced significant increases in HSP72 (P < 0.001) and HSP32 (P = 0.003) post-exercise in EXB1; this response was absent for HSP72 (P ≥ 0.79) and HSP32 (P ≥ 0.99) post-EXB2. The hypoxia-mediated increased bio-available HSP32 and HSP72 and favourable alterations in glutathione redox, prior to exercise commencing in EXB2 compared to EXB1, may acquiesce the disturbances to redox balance encountered during the second physiologically identical exercise bout.

Do the speeds defined by the American College of Sports Medicine metabolic equation for running produce target energy expenditures during isocaloric exercise bouts?

The accuracy of the American College of Sports Medicine (ACSM) equations for producing predicted values of heart rate reserve (HRR) and oxygen uptake reserve (VO2R) and consequently, target energy expenditure (EE) during exercise are yet to be established. This study investigated whether speeds defined by the ACSM metabolic equation for running correctly estimate the EEs during isocaloric exercise bouts. Twenty-eight men performed a ramp-incremental maximal exercise test to determine HRmax and VO2max. Two continuous exercise bouts at 60 and 80% VO2R and target EE of 400 kcal were then performed. In the 60% VO2R exercise the observed VO2R and EE were lower than predicted only during the first time quartile of the bout (t = 6.5, p < 0.001), whereas at 80% VO2R it was lower during the first (t = 15.3, p < 0.001), second (t = 5.4, p < 0.001) and third (t = 3.1, p = 0.025) quartiles. The observed HR was lower than predicted in the first time quartile of the 60% [Formula: see text] (t = 5.6, p < 0.001) and 80% VO2R bouts (t = 10.7, p < 0.001), whereas no significant differences occurred for any other time quartiles (p ≥ 0.23). In conclusion, the running speed defined by the ACSM metabolic equation overestimated VO2R and EE within exercise performed at 60 and 80% VO2R especially in higher intensities.

The relationship between oxygen uptake reserve and heart rate reserve is affected by intensity and duration during aerobic exercise at constant work rate

The relationship between the percentage of heart rate reserve (%HRR) and percentage of oxygen uptake reserve (%VO2R) has been recommended for prescribing aerobic exercise intensity. However, this relationship was derived from progressive maximal exercise testing data, and the stability of the relationship during prolonged exercise at a constant work rate has not been established. The main aim of this study was to investigate the stability of the %VO2R–%HRR relationship during prolonged treadmill exercise bouts performed at 3 different constant work rates. Twenty-eight men performed 4 exercise tests: (i) a ramp-incremental maximal exercise test to determine maximal heart rate (HRmax) and maximal oxygen uptake (VO2max) and (ii) three 40-min exercise bouts at 60%, 70%, and 80% VO2R. HR and VO2 significantly increased over time and were influenced by exercise intensity (p < 0.001 and p = 0.004, respectively). A 1:1 relationship between %HRR and %VO2R, and between %HRR and %VO2max, was not observed, with mean differences of 8% (t = 5.2, p < 0.001) and 6% (t = 4.8, p < 0.001), respectively. The VO2 values predicted from the ACSM running equation were all significantly higher than the observed VO2 values (p < 0.001 for all comparisons), whereas a difference for HR was observed only for the tenth min of exercise at 80% VO2R (p = 0.041). In conclusion, the main finding of this study was that the %HRR–%VO2R relationship determined by linear regression, obtained from progressive maximal exercise testing, did not apply to prolonged treadmill running performed at 3 work rates.

The effect of hyperbaric oxygen preconditioning on heat shock protein 72 expression following in vitro stress in human monocytes

Hyperbaric oxygen (HBO) is thought to confer protection to cells via a cellular response to free radicals. This process may involve increased expression of heat shock proteins, in particular the highly inducible heat shock protein 72 (Hsp72). Healthy male volunteers (n = 16) were subjected to HBO for 1 h at 2.8 ATA. Inducible Hsp72 expression was measured by flow cytometry pre-, post- and 4 h-post HBO. Peripheral blood mononuclear cells (PBMC) were isolated from whole blood via density centrifugation pre-, post- and 4 h post-HBO. PBMC were then subjected to an in vitro heat shock at 40°C or hypoxia at 37°C (5% O(2)) with a control at 37°C. Cells were then analysed for Hsp72 expression by flow cytometry. Monocytes showed no significant changes in Hsp72 expression following HBO. No detectable Hsp72 was seen in lymphocytes or neutrophils. Following in vitro hypoxic exposure, a significant increase in Hsp72 expression was observed in monocytes isolated immediately post- (p = 0.006) and 4 h post-HBO (p = 0.010) in comparison to control values. HBO does not induce Hsp72 expression in PBMC. The reported benefits of HBO in terms of pre-conditioning are not due to inducement of Hsp72 expression in circulating blood cells, but may involve an enhancement of the stress response.

Pre-exercise alkalosis attenuates the heat shock protein 72 response to a single-bout of anaerobic exercise

The heat shock protein 72 (HSP72) response following exercise is well documented, however, little is known on whether the expression may be mediated by the ingestion of ergogenic aids prior to performance. The purpose of this research was to investigate the effect of sodium bicarbonate (NaHCO(3)) ingestion on monocyte and lymphocyte expressed HSP72 and oxidative stress for 4-h post exercise. Seven active males (22.3 ± 2.9 years, 181.6 ± 4.5 cm, 78.1 ± 8.1 kg) performed a 4-min 'all-out' cycle test following a dose of 0.3 g kg(-1) body mass of NaHCO(3), or an equimolar placebo dose of sodium chloride. HSP72 was measured by flow cytometry and oxidative stress was determined via plasma thiobarbituric acid substances (TBARS) analysis. The NaHCO(3) ingestion significantly increased blood pH (p<0.001), bicarbonate (p<0.001) and base excess (p<0.001) pre-exercise. Despite this there was no evidence of a significantly improved exercise performance when compared with the placebo trials (p ≥ 0.26) (means ± SD; average power 292 ± 43 W vs. 291 ± 50 W; peak power 770 ± 218 W vs. 775 ± 211 W; work completed 71 ± 10 kJ vs. 68 ± 10 kJ). Monocyte expressed HSP72 was significantly lower under experimental conditions during the 4-h post-exercise (p=0.013), as was plasma TBARS (p<0.001). These findings suggest that pre-exercise alkalosis can attenuate the stress response to a single bout of anaerobic exercise.