A Rapidly-Incremented Tethered-Swimming Test for Defining Domain-Specific Training Zones

Abstract

The purpose of this study was to investigate whether a tethered-swimming incremental test comprising small increases in resistive force applied every 60 seconds could delineate the isocapnic region during rapidly-incremented exercise. Sixteen competitive swimmers (male, n = 11; female, n = 5) performed: (a) a test to determine highest force during 30 seconds of all-out tethered swimming (Favg) and the ΔF, which represented the difference between Favg and the force required to maintain body alignment (Fbase), and (b) an incremental test beginning with 60 seconds of tethered swimming against a load that exceeded Fbase by 30% of ΔF followed by increments of 5% of ΔF every 60 seconds. This incremental test was continued until the limit of tolerance with pulmonary gas exchange (rates of oxygen uptake and carbon dioxide production) and ventilatory (rate of minute ventilation) data collected breath by breath. These data were subsequently analyzed to determine whether two breakpoints defining the isocapnic region (i.e., gas exchange threshold and respiratory compensation point) were present. We also determined the peak rate of O2 uptake and exercise economy during the incremental test. The gas exchange threshold and respiratory compensation point were observed for each test such that the associated metabolic rates, which bound the heavy-intensity domain during constant-work-rate exercise, could be determined. Significant correlations (Spearman’s) were observed for exercise economy along with (a) peak rate of oxygen uptake (ρ = .562; p < 0.025), and (b) metabolic rate at gas exchange threshold (ρ = −.759; p < 0.005). A rapidly-incremented tethered-swimming test allows for determination of the metabolic rates that define zones for domain-specific constant-work-rate training.

Sex-Specific Effect on Accumulated Oxygen Deficit During Short and Middle-Distance Swimming Performance

“…In the current study, the difference between sexes for the slope was about 8.8%, with female swimmers showing higher values than males. The observed difference in slope between sexes might be considered not too large, when comparing with other studies in swimming that reported slopes differing from 13 to 25% between sexes (Fernandes et al, 2005;Pessôa Filho et al, 2017).…”

“…Regarding the slope, which is a rate relating VȮ 2 to submaximal velocities, it is an index of the oxygen cost for the increment in exercise intensity (Green and Dawson, 1995;Pessôa Filho et al, 2017), which accounts for more than half of the variance in the AOD estimation (Medbo et al, 1988). In the current study, the difference between sexes for the slope was about 8.8%, with female swimmers showing higher values than males.…”

A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers

“…Participants in the study from which the representative-subject data presented below were extracted 20 (n = 11) were required to give their written informed consent prior to initiation of testing after the experimental procedures, associated risks and potential benefits of participation had been explained. The first visit comprised a familiarization session during which the swimmers were introduced to the concept of tethered swimming and the measurement techniques that would be in effect during the actual testing.…”

“…It is, therefore, not surprising that only a single metabolic breakpoint (typically called the "anaerobic threshold") is reported by researchers who employ this test 18,19 . Instead, we have recently shown that both VO 2GET and VO 2RCP can be determined from data collected while swimmers performed stationary swimming in a pool against a load that was increased gradually and rapidly (i.e., incremental tethered swimming) 20 . While the unique breathing pattern that is present during swimming might render the aforementioned breakpoints harder to identify compared to typical modes of assessment (personal observation), we believe that this method of testing might be suitable as a "swim ergometer" that can be used for cardiorespiratory assessment of swimmers in a manner similar to how a stationary cycle is used for cyclists.…”

“…One important caveat to our contention that the tethered-swimming test we have described can serve as a "swim ergometer" for measuring cardiorespiratory parameters that are relevant for free swimming is that the degree to which the tethered methodology alters technique sufficiently to dissociate the two requires further elucidation. For example, when reporting the highest VO 2 measured during the test 16 , we are reticent to refer to it as the VO 2max because we did not have swimmers also perform a free-swimming INC in our study 20 . Consequently, we cannot confirm that the VO 2peak during the tethered test is similar to that which is measured using a free-swimming protocol.…”