## 4 Discussion and Implications
It was found that the swimming velocities attained differ from technique to technique and are in the same hierarchical sequence shown by the metabolic curves (females: max \(v_{0\text{exp}}=1.70\) m\(\cdot\)s\({}^{-1}\) in front crawl, min \(v_{0\text{exp}}=1.41\) m\(\cdot\)s\({}^{-1}\) in breaststroke; males: max \(v_{0\text{exp}}=1.84\) m\(\cdot\)s\({}^{-1}\) in front crawl, min \(v_{0\text{exp}}=1.52\) m\(\cdot\)s\({}^{-1}\) in breaststroke). Simultaneously, the metabolic power range between \(P_{ai}\) values was between a maximum of 2575 W (front crawl) and a minimum of 2248 W (breaststroke) for females, and between a maximum of 3560 W (front crawl) and a minimum of 3400 W (backstroke) for males. Male values were higher, as expected, than those obtained for female subjects. The referred differences are primarily related to the swimming time of the last 100 m lap of the step-test (for females, \(t=58.1\) s in front crawl and \(t=70.3\) s in breaststroke, and for males, \(t=53.5\) s in front crawl and \(t=65.1\) s in breaststroke). Values of \(P_{ai(\text{sa})}\) were quite acceptable when comparing results from the [PERSON]'s approach (second approach described in the Methods Section) to determine the metabolic power at the last stage of the test (as \(P_{ai(\text{sa})}=P_{ti}-P_{bi}\)). Only slightly higher individual values (as \(\Delta=P_{ai(\text{sa})}-P_{ai}\)) than those obtained through Equation (2) and presented in Table 2 for females: min\(\Delta=21\) W front crawl, max\(\Delta=171\) W backstroke, and Table 3 for males: min\(\Delta=146\) W for backstroke, max\(\Delta=270\) W for breaststroke, were observed. In all swimming strokes, \(P_{to}\) and \(e_{g}\) values were within a relatively narrow range of values, both for females and males (\(P_{to}\): females: max = 128 W in front crawl, min = 113 W in breaststroke, males: max = 220 W in butterfly, min = 208 W in backstroke; \(e_{g}\): females: max = 0.052 for breaststroke, min = 0.049 for butterfly, males: max = 0.068 for butterfly, min = 0.062 for front crawl). It is important to note that maximum and minimum values of \(P_{to}\) and \(e_{g}\) were observed in different swimming techniques for both genders. According to these values (\(P_{to}\) and \(e_{g}\)), male swimmers have an obvious advantage over females. The indicated range of \(e_{g}\) values at maximum swimming speed is expressively lower than \(e_{g}\) values previously obtained for female and male subjects during land locomotion at maximum intensity (females: \(e_{g}=0.17\)-0.19, males: \(e_{g}=0.20\)-0.23) [19]. Meanwhile, in a large analytical review [18] devoted to the analysis of \(e_{g}\) obtained using various experimental methods, the authors indicated a significantly wider range of values of this variable than those obtained in our study--from 0.03 to 0.23, though the maximum \(e_{g}\) values obtained when determining \(P_{to}\) in on-land activity using a simulator (a whole-body \"swimming ergometer\" [40]) coincide with the magnitudes of \(e_{g}\) established in tests on a bicycle ergometer. It should be noted here that methods which simulate swimming movements using dry-land ergometers violate such important criteria as Re\({}_{1}\) and Sh\({}_{0}\), which contradicts the theory of mechanical similarity and the dimensions of nonstationary processes [34; 35; 36] and makes it difficult to correctly compare such data with the results that are obtained in real aquatic locomotion (such as swimming). In all swimming strokes, \(e_{p}\) values for male swimmers were within a range of values between 0.71 (in breaststroke) and 0.65 (in butterfly), which does not differ from analogous indicators for female subjects: max 0.71 in breaststroke, min 0.67 in front crawl and butterfly. Male and female subjects do not differ from each other in this variable, which is in accordance with earlier experimental data [16; 38]. According to this characteristic, elite swimmers are inferior not only to dolphins, but also to elite mono-fin swimmers.