# Monitoring of Training Load and Body Composition in Elite Male Kayakers
## 4 Discussion
Maximal oxygen uptake (\(\mathrm{VO_{2 max}}\)) and \(\mathrm{VO_{2 peak}}\) are related to aerobic power, and are important variables for kayak performance even for a more explosive event as the 200 m kayaking race [14]. In kayakers, \(\mathrm{VO_{2 max}}\) and \(\mathrm{VO_{2 peak}}\) assessments can be influenced by the type of ergometer used; however, [PERSON] et al. [3], who examined well-trained kayakers, found no significant differences in \(\mathrm{VO_{2 peak}}\) obtained in the treadmill and kayak ergometer in two moments of the season, but the values obtained with the treadmill inclined was higher. Although the kayak ergometer cannot completely replicate on-water kinematics, it seems that the physiological responses after short-term high-intensity kayaking are similar. [PERSON] et al. [1], who examined well-trained kayakers, found similar \(\mathrm{VO_{2 peak}}\) values in open water kayaking (4.10 \(\pm\) 0.49 L-min\({}^{-1}\)) and in the kayak ergometer (4.09 \(\pm\) 0.53 L-min\({}^{-1}\)) as well as approximate blood lactate values after the all-out 4 min test. Corroborating these data, [PERSON] et al. [9] found similar values of \(\mathrm{VO_{2 peak}}\) and maximum lactate after progressive treadmill test until volitional exhaustion at kayak ergometer in Hungarian elite kayaker. In our study, \(\mathrm{VO_{2 peak}}\) increased progressively during the season, both in absolute and relative terms. \(\mathrm{VO_{2 peak}}\) values in our kayakers at the start of the competitive period (M3) were higher than those obtained in other studies as the elite Hungarian kayakers (~4.4 \(\pm\) 0.6 L-min\({}^{-1}\) or ~56.4 \(\pm\) 4.1 mL-kg\({}^{-1}\cdot\)min\({}^{-1}\)) [10], but similar (~4.8 \(\pm\) 0.4 L-min\({}^{-1}\) or ~61.4 \(\pm\) 4.4 mL-kg\({}^{-1}\cdot\)min\({}^{-1}\)) to the values found with on-water progressive testing by [PERSON] et al. [15] in elite Italian kayakers. The \(\mathrm{VO_{2 max}}\) values obtained by [PERSON] et al. [1] in a test like ours are clearly lower than those obtained in the present study (4.1 \(\pm\) 0.51 L-min\({}^{-1}\)) which may be related to differences in performance level between samples. Nevertheless, it cannot be ruled out that the training profile of Hungarian kayakers places greater emphasis on anaerobic training, thus reducing maximal aerobic expression. The progressive increase in \(\mathrm{VO_{2 peak}}\) during the season observed in our study can mean (i) a significant loss of aerobic power during the off-season, (ii) a progressive adaptation to the kayak-ergometer, or (iii) a better training plan. In this study, blood lactate behavior 3 min after effort did not show significant differences (\(p>\) 0.05). Blood lactate concentration 5 min after effort showed significant differences (\(p=\) 0.004) between M1 and M3. It is challenging to attribute a clear physiological meaning to this difference. Based on our data, it can be inferred that the stability in blood lactate behavior, combined with the improvement in kayak ergometer performance, aligns with the observed enhancement in \(\mathrm{VO_{2 peak}}\). The potentiation of aerobic mechanisms, e.g., increased capillary density, increased quantity of mitochondrial enzymes, and improved \(\beta\)-oxidation, is reflected either in the superior capacity to oxidize lactate in the mitochondria or the improvement of lactate oxidation in the surrounding fibers. Blood lactate values after exertion in our study are like those obtained by [PERSON] et al. [10] in elite Hungarian kayakers (12.0 \(\pm\) 0.9 mmol\(\cdot\)L\({}^{-1}\)). Interestingly, a 300 m all-out effort in flat water, lasting between 79 and 102 s, elicited similar blood lactate values (11.9 mmol\(\cdot\)L\({}^{-1}\)) [16] to the 4 min all-out effort in our study. This is in line with the results from [PERSON] et al. [17] who found identical blood lactate levels after running competition with 20.1\(\pm\) 2.2, 21.9 \(\pm\) 2.1, and 20.8 \(\pm\) 2.7 mmol\(\cdot\)L\({}^{-1}\) for the 400 m, 800 m, and 1500 m, respectively.