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Anatomy, Biomechanics, Work Physiology, and Anthropometry
Published in Stephan Konz, Steven Johnson, Work Design, 2018
Figure 2.26 shows how the heart rate (primarily determined by aerobic oxygen supply) responds to constant-intensity exercise. At the start of exercise, the aerobic response (and therefore heart rate) lags. (Aerobic refers to reactions using oxygen from the lungs.) The resulting deficit (Figure 2.26, area A) is replaced by anaerobic oxygen. Anaerobic (without oxygen) reactions use oxygen stored as compounds in the blood. The anaerobic supply is composed of alactate (energy equivalent of 1.9 L of oxygen) and lactate (equivalent of 3.1 L). During recovery (Figure 2.26, area C), the anaerobic oxygen used from the blood is replaced; however, the replacement process itself uses oxygen (“interest”), so area C is larger than area A. Area C, the excess post-exercise oxygen consumption, is also known as “after-burn.” Typically it amounts to 10–15% of the calories consumed during exercise. Thus, during exercise you burn a few more calories than shown in the direct metabolic measurements. For task cost, use areas B + C. The heart rate cost of work can be determined three ways. The simplest is to subtract an individual’s basal heart rate from the peak. For example, Joe’s peak of 110 and basal of 70 give a task cost for him of 40 beats/min. This assumes that the peak represents the work heart rate—that is, that the top of the curve in Figure 2.26 is flat.
Metabolic demands of slacklining in less and more advanced slackliners
Published in European Journal of Sport Science, 2023
Jiří Baláš, Jan Klaus, Jan Gajdošík, Nick Draper
Some limitations and strengths of the study have to be acknowledged. The measurement was undertaken in an ecologically valid setting with a relatively high number of participants. The participants wore a face mask which might have reduced visual control and, therefore, increased the difficulty of the task (Houdijk et al., 2009). We did not assess metabolic excess of V̇CO2 and excess post-exercise oxygen consumption (EPOC). A V̇O2 steady state (no increases in V̇O2) was attained in each testing condition and the V̇CO2 /V̇O2 exchange ratio did not exceed 1.00 in any participant. Hence, we suggest that any metabolic excess of V̇CO2 and an EPOC would have only minor effect on the current results. Moreover, the study design necessitated six testing conditions and additional rest between conditions. To allow for monitoring of EPOC values would have greatly increased the test time for each participant, which would have increased the risk of participants encountering central fatigue (due to increased attention demands and time wearing face mask, etc.). As a consequence, we completed the study with the described methodology for each participant.
Energy pathway contributions during 60-second upper-body Wingate test in Greco-Roman wrestlers: intermittent versus single forms
Published in Research in Sports Medicine, 2022
Süleyman Ulupınar, Serhat Özbay
Height and body mass were measured using standardized methods. Body composition was assessed using a tetrapolar bioelectrical impedance analyser (Tanita TBF 401A, Japan). HR (Polar 810i, Polar Electro, Kempele, Finland) and VO2 (K5b2, Cosmed, Rome, Italy) were measured continuously throughout the Wingate tests. Additionally, VO2 was measured for 10 min before the tests to determine resting VO2 (the last 5 min was used in the analysis) and 15 min following the tests to observe the fast and slow phases of excess post-exercise oxygen consumption (EPOC). Lactate was measured from capillary blood samples drawn from the fingertip of the left hand using a portable hand analyser (Lactate Pro, Arkray, Japan) before the tests and in the 1st, 3rd, 5th, and 7th min post-exercise. Before each test, the gas and lactate analysers were calibrated in accordance with the manufacturer’s recommendations. RPE was recorded immediately after each test based on participants’ answers using the Borg’s 15 grade scale (6–20) for RPE (Borg, 1982).
Exaggerated post exercise hypotension following concentric but not eccentric resistance exercise: Implications for metabolism
Published in European Journal of Sport Science, 2019
Jon Stavres, Stephen M Fischer, John McDaniel
As with any study, this project had certain limitations to its study design. One limitation is that we could not concurrently control for volume of worked performed and the overall length of the exercise session. We chose to control for total work performed due to its influence on the PEH response, as reported by Jones et al. (2007). Thus, since the TRAD session included half of the repetitions performed in the other two sessions, the TRAD session was shorter. Similarly, we did not account for the excess post-exercise oxygen consumption period (due to laboratory constraints), which would very likely have augmented the differences in total oxygen consumption between CONC and TRAD. We were also unable to collect and analyse for any blood markers, such as histamine or circulating catecholamine. This information may have provided valuable mechanistic insight; future studies should consider including these variables. Lastly, the order of our exercises (specifically, lower body exercises being performed early and the last two exercises being arm exercises) may have reduced any significant interactions that may have otherwise been observed in the lower body. This may have resulted in us missing any significant interaction that may have otherwise been observed with femoral blood flow. Our goal was to elicit a robust PEH response, and therefore we used a full-body resistance exercise protocol. In the future, it may be beneficial to use only lower body exercise to determine if the same responses observed in the upper body also occur in the lower body.