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).
To compare the highest VO2 responses observed in different verification phase procedures with their preceding CPET for confirmation that VO2max was likely attained.
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.
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.
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.
CRD42019123540.
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.
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
).
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.
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.
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%).
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.
PROSPERO (CRD42021247658) https://www.crd.york.ac.uk/prospero.
Although the concept of maximal oxygen uptake (V-dotO(2max)) was conceived as early as 1923, the criteria used to establish whether a true V-dotO(2max) has been attained have been heavily criticised. ...Consequently, an improvement in the methodology of the existing criteria, or development of new criteria, is required. In order to be valid across experimental studies, new or improved criteria need to be independent of exercise modality, test protocol and subject characteristics. One procedure that has shown potential for yielding valid V-dotO(2max) criteria is the verification phase, which consists of a supramaximal constant speed run to exhaustion performed after the incremental phase of a V-dotO(2max) test. A peak oxygen uptake (V-dotO(2peak)) in the verification phase that is similar (within the tolerance of measurement error, e.g. within 2%) to the V-dotO(2max) value attained in the incremental phase would indicate that a true V-dotO(2max) has been elicited. Verification of the maximal heart rate would also indicate that a subject has given a maximum effort. Although the validity of the present methodology for identifying an oxygen uptake (V-dotO(2)) plateau is questionable, a V-dotO(2) plateau criterion based on the individual slope of the V-dotO(2)-work-rate relationship should improve its validity. This approach also allows determination of the 'total V-dotO(2) plateau', which is in contrast to currently used V-dotO(2) plateau criteria that are based on the difference in V-dotO(2) between only two test stages or V-dotO(2) data points. The ratings of perceived exertion scale has been criticised for being a one-dimensional measure of physical effort and V-dotO(2max) criteria based on a multidimensional psychophysiological approach should increase validity. Visual analogue scales can be used to assess aspects such as muscular pain, determination and overall perceived effort. Furthermore, they are easy to complete and have demonstrated good reliability and validity in clinical and health settings. Future research should explore these and other potential approaches to developing new or improved V-dotO(2max) criteria, so that, ultimately, a standardised set of V-dotO(2max) criteria can be established. At present, however, the greatest challenge is identifying V-dotO(2max) criteria that remain valid across studies.
To assess the acute alterations in triaxial accelerometry (PlayerLoad PL(VM)) and its individual axial planes (anteroposterior PlayerLoad PL(AP), mediolateral PlayerLoad PL(ML), and vertical ...PlayerLoad PL(V)) during a standardized 90-min soccer match-play simulation (SAFT90). Secondary aims of the study were to assess the test-retest reliability and anatomical location of the devices.
Semiprofessional (n = 5) and university (n = 15) soccer players completed 3 trials (1 familiarization, 2 experimental) of SAFT90. PlayerLoad and its individual planes were measured continuously using micromechanical-electrical systems (MEMS) positioned at the scapulae (SCAP) and near the center of mass (COM).
There were no between-halves differences in PL(VM); however, within-half increases were recorded at the COM, but only during the 1st half at the SCAP. Greater contributions to PL(VM) were provided by PL(V) and PL(ML) when derived from the SCAP and COM, respectively. PL(VM) (COM 1451 ± 168, SCAP 1029 ± 113), PL(AP) (COM 503 ± 99, SCAP 345 ± 61), PL(ML) (COM 712 ± 124, SCAP 348 ± 61), and PL(V) (COM 797 ± 184, SCAP 688 ± 124) were significantly greater at the COM than at the SCAP. Moderate and high test-retest reliability was observed for PlayerLoad and its individual planes at both locations (ICC .80-.99).
PlayerLoad and its individual planes are reliable measures during SAFT90 and detected within-match changes in movement strategy when the unit was placed at the COM, which may have implications for fatigue management. Inferring alterations in lower-limb movement strategies from MEMS units positioned at the SCAP should be undertaken with caution.
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.
Randomised cross-over design.
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.
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.
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.
This article investigates whether there is currently sufficient scientific knowledge for scientists to be able to give valid training recommendations to long-distance runners and their coaches on how ...to most effectively enhance the maximal oxygen uptake, lactate threshold and running economy. Relatively few training studies involving trained distance runners have been conducted, and these studies have often included methodological factors that make interpretation of the findings difficult. For example, the basis of most of the studies was to include one or more specific bouts of training in addition to the runners' 'normal training', which was typically not described or only briefly described. The training status of the runners (e.g. off-season) during the study period was also typically not described. This inability to compare the runners' training before and during the training intervention period is probably the main factor that hinders the interpretation of previous training studies. Arguably, the second greatest limitation is that only a few of the studies included more than one experimental group. Consequently, there is no comparison to allow the evaluation of the relative efficacy of the particular training intervention. Other factors include not controlling the runners' training load during the study period, and employing small sample sizes that result in low statistical power. Much of the current knowledge relating to chronic adaptive responses to physical training has come from studies using sedentary individuals; however, directly applying this knowledge to formulate training recommendations for runners is unlikely to be valid. Therefore, it would be difficult to argue against the view that there is insufficient direct scientific evidence to formulate training recommendations based on the limited research. Although direct scientific evidence is limited, we believe that scientists can still formulate worthwhile training recommendations by integrating the information derived from training studies with other scientific knowledge. This knowledge includes the acute physiological responses in the various exercise domains, the structures and processes that limit the physiological determinants of long-distance running performance, and the adaptations associated with their enhancement. In the future, molecular biology may make an increasing contribution in identifying effective training methods, by identifying the genes that contribute to the variation in maximal oxygen uptake, the lactate threshold and running economy, as well as the biochemical and mechanical signals that induce these genes. Scientists should be cautious when giving training recommendations to runners and coaches based on the limited available scientific knowledge. This limited knowledge highlights that characterising the most effective training methods for long-distance runners is still a fruitful area for future research.
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.
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