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

Abstract

Incremental exercise testing is the standard means of assessing cardiorespiratory capacity of endurance athletes. While the maximal rate of oxygen consumption is typically used as the criterion measurement in this regard, two metabolic breakpoints that reflect changes in the dynamics of lactate production/consumption as the work rate is increased are perhaps more relevant for endurance athletes from a functional standpoint. Exercise economy, which represents the rate of oxygen consumption relative to performance of submaximal work, is also an important parameter to measure for endurance-athlete assessment. Ramp incremental tests comprising a gradual but rapid increase in work rate until the limit of exercise tolerance is reached are useful for determining these parameters. This type of test is typically performed on a cycle ergometer or treadmill because there is a need for precision with respect to work-rate incrementation. However, athletes should be tested while performing the mode of exercise required for their sport. Consequently, swimmers are typically assessed during free-swimming incremental tests where such precision is difficult to achieve. We have recently suggested that stationary swimming against a load that is progressively increased (incremental tethered swimming) can serve as a "swim ergometer" by allowing sufficient precision to accommodate a gradual but rapid loading pattern that reveals the aforementioned metabolic breakpoints and exercise economy. However, the degree to which the peak rate of oxygen consumption achieved during such a protocol approximates the maximal rate that is measured during free swimming remains to be determined. In the present article, we explain how this rapidly incremented tethered-swimming protocol can be employed to assess the cardiorespiratory capacity of a swimmer. Specifically, we explain how assessment of a short-distance competitive swimmer using this protocol revealed that his rate of oxygen uptake was 30.3 and 34.8 mL•min -1•kg -1 BM at his gas-exchange threshold and respiratory compensation point, respectively.

Oxygen Uptake Kinetics and Time Limit at Maximal Aerobic Workload in Tethered Swimming

“…The load cell was previously calibrated for 100 Hz signal acquisition, with smoothing performed by the manufacturer’s software package (N2000PRO, Cefise ® , São Paulo, Brazil). Swimmers performed the full front crawl style, trying to displace the body forward as strongly as possible (unsuccessfully) for 30 s (e.g., an all-out bout) for the analysis of force (e.g., mean peaks of force in the 30 s, Fmean), following previous recommendations [ 9 , 13 ]. In summary, these authors [ 9 , 13 ] suggested to consider a baseline (e.g., the force required to align the swimmer horizontally in water and extend the rope system with minimal strain, which should be measured just before the onset of the all-out bout) for the measurement of Fmean.…”

“…Swimmers performed the full front crawl style, trying to displace the body forward as strongly as possible (unsuccessfully) for 30 s (e.g., an all-out bout) for the analysis of force (e.g., mean peaks of force in the 30 s, Fmean), following previous recommendations [ 9 , 13 ]. In summary, these authors [ 9 , 13 ] suggested to consider a baseline (e.g., the force required to align the swimmer horizontally in water and extend the rope system with minimal strain, which should be measured just before the onset of the all-out bout) for the measurement of Fmean. The fractions of Fmean were the WL applied to grade the swimming intensity during each stage of the ITT.…”

“…Swimmers performed the ITT until voluntary exhaustion attached to a weight-bearing pulley rope system. As previously recommended [ 9 , 13 ], the swimmers were instructed to administer the front crawl with a propelling force to avoid being pulled back or forward as the WL was applied from 30% of Fmean (i.e., =(100%Fmean − baseline load) × 0.3), with increments of 5% per minute. Pulmonary gas exchange was analyzed breath by breath by a portable and automatized metabolic unit (CPET K4b2, Cosmed, Rome, Italy) coupled to a specific snorkel designed and validated for swimming (Cosmed new-AquaTrainer ® , Rome, Italy) [ 27 ].…”

“…In spite of these physiological findings, tethered swimming would still need to demonstrate reliability in contextualizing the physiological information during different levels of loads applied to graded swimming intensity, thus ensuring it is validated as an ergometer. In the context of incremental exercise, tethered swimming has been considered a reliable ergometer to ensure the temporal resolution between breath-by-breath pulmonary gas exchange response and loading management during a ramp test, which was designed to define the exercise domains from the assessment of gas exchange threshold (GET), respiratory compensation point (RCP), and peak oxygen uptake (VO 2peak ) [ 9 , 13 ]. In addition, these studies also demonstrated the representativeness of the VO 2 response to different load stimuli based on individual references of maximal tethered force.…”

Body Composition Relationship to Performance, Cardiorespiratory Profile, and Tether Force in Youth Trained Swimmers

“…Previous scientific evidence underlined that for strength measurement, tethered swimming is the most specific in-water test [ 28 ] and can be used with the purpose of evaluating the cardiorespiratory capacity of a swimmer [ 29 ], associated with indications that the relationship between the body composition and performance of swimmers has been a source of unceasing interest among scientists, especially in young athletes [ 30 ]. To our best knowledge, no study has analyzed the relationship between regional body composition, force, and aerobic variables determined throughout tethered swimming and performance in different distance swimming trials in well-trained swimmers.…”