All authors reviewed and approved the manuscript. The regulation of respiration and circulation during the initial stages of muscular work. Frontera, W. R., Meredith, C. N., O’Reilly, K. P., and Evans, W. J. Strength training and determinants of V˙O2max in older men. Buchfuhrer, M. J., Hansen, J. E., Robinson, T. E., Sue, D. Y., Wasserman, K., and Whipp, B. J. Optimizing the exercise protocol for cardiopulmonary assessment.
The participants visited the university laboratory on five occasions (Fig. 1) to complete the study. The sessions were separated by 48–72 h between the first four visits and by 7–10 days between the fourth and the fifth visit. All tests were performed using a motored treadmill (Super ATL, Inbrasport, Porto Alegre, RS, Brazil), a gas analyser (Metalyzer II, Cortex, Leipzig, Germany) that was calibrated before each test according to the manufacturer’s instructions, a heart rate monitor (Polar S810i, Kemple, Finland) and a Borg perception effort scale34.
Following this screening session, individuals deemed appropriate for inclusion returned to the laboratory on another day for the final stage of pre-trial screening before beginning the nine-day parent study. This visit occurred in the morning with participants in the fasted state having refrained from consuming calorie-containing foods and beverages for 12 hrs. Participants were also instructed to refrain from ingesting any product containing caffeine and/or alcohol for this 12-hr period and to avoid moderate or strenuous activity for the prior 24 hrs. The first test during this visit required participants to lie supine on a bed with a hood placed over their head so that gas exchange and ventilation could be measured for 60 min. The purpose was to determine the participant’s resting metabolic rate. Following this procedure and while still in the fasted state, participants performed the two exercise bouts from which the data presented in this article were derived.
However, it is important to note that only four of the 12 participants who did not achieve a greater ⩒o2peak during CWR were able to satisfy this criterion during RAMP-INC. While we cannot confirm that the RAMP-INC ⩒o2peak was ⩒o2max for these individuals (see above), it seems unlikely that it definitely was not for eight of the 12. Furthermore, this criterion HR value was equally difficult to achieve during CWR as only six of the 35 participants (all of whom also achieved it on RAMP-INC) were able to do so. This means that if this particular HR value was valid as a threshold indicator of the attainment of ⩒o2max (i.e., did not result in a high proportion of rejection of tests during which it actually was achieved), 29 of 35 participants in our study would not have achieved their ⩒o2max on either test. This seems unlikely, which implies that this value for HR is too stringent to be used for accepting that ⩒o2max has been achieved with this type of individual.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. 1Department of Sport and Exercise Science, University of Hull, Hull, UK; 2Department of Sport and Exercise Sciences, University of Bath, Bath, UK; 3Health and Sport Science, Department of Medical Sciences, University of New Wales, Sydney, Australia. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
S1 Table. Raw data.
Data were recorded using LabChart v4.2 (ADInstruments, Colorado Springs, CO) on a separate computer. First four sessions were separated by 48–72 h between them and the fifth by 7–10 days. INC incremental test, VER verification phase test, DEC decremental test, DEC–INC decremental–incremental test, INCF incremental final. Highest V˙O2 and HR values during the ramp incremental (RI) test and the verification phase for each subgroup.
However, these researchers used supramaximal work rates for CWR bouts performed long enough after RAMP-INC to allow ⩒o2 to return to its resting level; specifically, 105% of WRpeak after 24 hrs (study 1) and 115% of WRpeak after 60–90 min (study 2) [27]. These differences might explain the contrasting findings compared to our study. Sedentary individuals would likely possess slower ⩒o2 kinetics which would result in a higher proportion of “non-sustainable” work https://www.globalcloudteam.com/ rates (i.e., work rates situated above the “critical power”) that they would not be able to maintain long enough to reach ⩒o2max (i.e., work rates situated within the extreme-intensity domain). Given the importance placed on ⩒o2max and the array of individuals that are critically assessed using its measurement, it is intuitive to suggest that the ⩒o2peak achieved on a given INC should be verified as ⩒o2max in some other way when a ⩒o2 plateau is absent.
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The views expressed in this publication are those of the author(s) and not necessarily those of the funders. All authors had full access to all of the data (including statistical reports and tables) in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis. Data sharing statement Data are not publicly available, but applications for data sharing can be made. Breath-by-breath measurement of true alveolar gas exchange.
For example, secondary criteria are satisfied long before Tlim when athletes [11] and recreationally-active individuals [12] perform RAMP-INC. The degree to which traditional secondary criteria are useful might, therefore, depend on the physical-activity and/or obesity status of the individual. Moreover, Wagner et al. have recently proposed new age-dependent secondary criteria for RER and HR based on data collected during RAMP-INC cycling tests performed by a large cohort of healthy men and women aged 20–91 yr. In relation to the effectiveness of the verification phase to reach V˙O2max, the relationship between the intensity and the duration of the exercise should be considered.
Incremental test (INC) and verification phase test (VER)
Additionally, healthy older adults, for whom V˙O2max is the strongest predictor of independent living (Paterson and Warburton, 2010) and for whom a verification phase would theoretically be needed for accurate V˙O2max determination (Poole and Jones, 2017), have never previously been evaluated. Establishing if a verification phase actually adds confidence in the achievement of V˙O2max in this population would contribute to further support or oppose the recommendation of such practice. Several studies prescribed a more personalized approach with training recommendations based on HR values corresponding to the metabolic thresholds defined through IET (Ghosh, 2004; Meyer et al., 2005). That is why for the FATmax and FATmin points we present absolute and relative values of power and HR, as those variables are commonly used in controlling training intensity in cycling (Robinson et al., 2011). Available results suggest that both the metabolic thresholds and the points of fat oxidation are determined by the participants’ physical work capacity. In accordance with Meyer et al. (2005), it can then be concluded that the greater the athlete’s efficiency, the higher the intensity level at which he/she reaches his/her thresholds.
Achten et al. (2002) suggest that 3-min stages are optimal to reach a state of equilibrum and define MFO for well-trained athletes. Others recommend four to six longer (60 min) continuous exercise cycles, executed on separate days, at the intensity used in the IET (Meyer et al., 2007; Takagi et al., 2014). The latter approach may, however, be excessively time-consuming and therefore inconvenient in sports training.
Those of which include fitness tests such as the YMCA sub-maximal test, YoYo test, Leger test, and Beep test. An incremental exercise test (IET) is a physical fitness test that varies by different variables. These include the initial starting rate, the consecutive work rates, increments and the duration of each increment. These variables can be modified extensively to suit the purpose of the training program or the individual.[2] Incremental exercise is a widely accepted method of sourcing health-related information. At the University of Verona, breath-by-breath gas exchange and ventilation were continuously measured using a metabolic cart (QuarkB2; COSMED, Rome, Italy) as previously described (Keir et al., 2015). The gas analyzers were calibrated before each experiment using a gas mixture of known concentration, and the turbine flowmeter was calibrated using a 3-L syringe (Hans Rudolph, Inc.).
- The authors would like to thank prof. Wojciech Zatoń for translation and the subjects participating in the study and their coaches.
- At the University of Verona, breath-by-breath gas exchange and ventilation were continuously measured using a metabolic cart (QuarkB2; COSMED, Rome, Italy) as previously described (Keir et al., 2015).
- It was important to verify the usefulness of the verification phase in the same population in which the verification phase has been proposed; however, the absence of female participants in this study is an issue that, although not expected to change the outcome observed in the present investigation, might need to be addressed in future studies.
- No use, distribution or reproduction is permitted which does not comply with these terms.
- In addition, a strong correlation was observed between the FATmax intensity delineated in the RAMP test and AeT for the probed variables which were used in monitoring exercise intensity.
HR data were collected using radiotelemetry (SP0180 Polar Transmitter; Polar Electro, Inc., Kempele, Finland) and calculated over the duration of each breath. Gas-exchange measurements at the University of Western Ontario were conducted as previously described (Babcock et al., 1994). Briefly, inspired and expired flow rates were measured using a low dead space (90 mL) bidirectional turbine (Alpha Technologies VMM 110) which was calibrated before tests using a syringe of known volume. Inspired and expired gases were sampled continuously (every 20 ms) at the mouth and analyzed for concentrations of O2, CO2, and nitrogen (N2) by mass spectrometry (Perkin Elmer MGA-1100) after calibration with precision-analyzed gas mixtures. Breath-by-breath alveolar gas exchange was calculated using the algorithms of Beaver et al. (1981). Heart rate (HR) was monitored continuously by a three-lead arrangement electrocardiogram using PowerLab (ML132/ML880; ADInstruments, Colorado Springs, CO).
Similarly, measures of V˙O2max have been used to determine the efficacy of different exercise training interventions aimed at improving physiological function both from performance as well as health perspectives (Pogliaghi et al., 2006; Murias et al., 2010a; Bruseghini et al., 2015). Considering the importance of V˙O2max for assessment of performance and health, adequate protocols capable of establishing a true maximal value are needed to provide confidence for evaluation and longitudinal follow-up. Despite the interesting findings, some limitations of the study should be mentioned.
In the present study, the times to exhaustion for the verification phases performed five min after the end of the RI test were ~2.5 and ~1.5 min for exercise performed at 85% and 105% of the peak PO, respectively. As found for the present data using 85% or 105% of the end-RI work rate, Sedgeman et al. (2013) also showed the V˙O2 values were not different between the RI test and the verification phase either with the sub-maximal (~2.2 min duration) or the supramaximal (~1.3 min duration) verification. These authors suggested that a sub-maximal verification phase might be beneficial as more plateau responses were observed during this type of verification.