# Physiological and Biomechanical Characteristics of Olympic and World-Class Rovers--Case Study
## 4 Discussion  
An increase in cardiorespiratory and metabolic variables was evident in rowing from the low to the severe intensity domains. When reaching the severe intensity, the observed maximal VO\({}_{2}\) values were in line with those for world-class male and female heavyweight rowers of younger age (male and female) [28; 32; 33]. These values also agree with longitudinal data reported for a 40-year-old world-class lightweight male rower [4]. In fact, high values for maximal VO\({}_{2}\) at younger ages and long-term engagement in endurance training seem to be necessary to perform at an elite level during a long career [4; 34; 35]. The HR values observed throughout the protocol were lower than those reached by younger rowers performing at maximal efforts [36], which is likely attributable to the aging process that involves a decline in cardiac output and impacts cardiorespiratory function, particularly during maximal efforts [36]. [La\({}^{-}\)] values are related to rowers' adaptations to endurance training, which increase their fatigue tolerance and clearance ability over their careers [5]. \begin{table} \begin{tabular}{c c c c c c} \hline \hline
**Variables** & **Low** & **Moderate** & **Heavy** & **Severe** & **Extreme** \\ \hline Physiological & & & & & \\ Oxygen uptake (mL/min/kg) & 47.4 \(\pm\) 1.6 & 57.8 \(\pm\) 1.4 & 60.4 \(\pm\) 2.1 & 69.7 \(\pm\) 1.5 * & 50.1 \(\pm\) 0.6 *\$ \\ Respiratory frequency (b/min) & 41.8 \(\pm\) 0.3 & 48.6 \(\pm\) 2.1 & 49.4 \(\pm\) 1.9 & 57.2 \(\pm\) 0.7 * & 53.2 \(\pm\) 4.3 \\ Ventilation (L/min) & 80.1 \(\pm\) 1.3 & 107.3 \(\pm\) 1.3 * & 117.0 \(\pm\) 1.6 * & 152.5 \(\pm\) 2.9 *\$ & 127.6 \(\pm\) 5.8 *\$ \\ Carbon dioxide production & & & & & \\ (mL/min/kg) & 38.2 \(\pm\) 0.7 & 51.7 \(\pm\) 1.1 * & 54.1 \(\pm\) 0.5 * & 73.0 \(\pm\) 1.5 *\$ & 51.2 \(\pm\) 4.5 * \\ Respiratory quotient & 0.8 \(\pm\) 0.0 & 0.9 \(\pm\) 0.0 * & 0.9 \(\pm\) 0.0 & 1.1 \(\pm\) 0.0 *\$ & 1.1 \(\pm\) 0.1 * \\ Heart rate (bpm) & 134 \(\pm\) 1 & 159 \(\pm\) 0 * & 168 \(\pm\) 1 * & 173 \(\pm\) 0 *\$ & 169 \(\pm\) 1 *\$ \\ Blood lactate (mmol/L) & 1.2 & 2.4 & 3.6 & 6.7 & 15.8 \\ Core temperature (*C) & 37.1 \(\pm\) 0.01 & 37.5 \(\pm\) 0.07 * & 37.8 \(\pm\) 0.09 * & 38.1 \(\pm\) 0.09 *\$ & 38.8 \(\pm\) 0.03 *\$ \\ \hline Mechanical Power & & & & & \\ Power (W) & 150 & 210 & 240 & 270 & 360 \\ Power (W/kg) & 1.9 & 2.7 & 3.1 & 3.5 & 4.8 \\ Work (J) & 174.0 & 212.1 & 237.6 & 237.6 & 259.0 \\ \hline Kinematic & & & & & \\ Rowing rate (cycles/min) & 21 & 24 & 26 & 34 & 46 \\ Rowing cycle length (m) & 1.55 \(\pm\) 0.01 & 1.53 \(\pm\) 0.01 * & 1.53 \(\pm\) 0.01 * & 1.39 \(\pm\) 0.12 * & 1.27 \(\pm\) 0.08 *\$ \\ Propulsive time (s) & 1.16 \(\pm\) 0.01 & 1.01 \(\pm\) 0.01 * & 0.99 \(\pm\) 0.01 * & 0.88 \(\pm\) 0.11 *\$ & 0.70 \(\pm\) 0.03 *\$ \\ Maximal seat velocity (m/s) & 1.27 \(\pm\) 0.02 & 1.39 \(\pm\) 0.02 * & 1.40 \(\pm\) 0.03 * & 1.28 \(\pm\) 0.15 *\$ & 1.23 \(\pm\) 0.14 *\$ \\ Maximal handle drive velocity & & & & & \\ (m/s) & 1.43 \(\pm\) 0.05 & 1.65 \(\pm\) 0.02 * & 1.72 \(\pm\) 0.05 *\$ & 1.95 \(\pm\) 0.26 *\$ & 2.39 \(\pm\) 0.12 *\$ \\ Catch factor (ms) & \(-\)10 \(\pm\) 10 & 10 \(\pm\) 10 & \(-\)10 \(\pm\) 10 & \(-\)20 \(\pm\) 10 *\$ & \(-\)20 \(\pm\) 10 *\$ \\ Rhythm (\%) & 40 \(\pm\) 0.50 & 39 \(\pm\) 0.70 * & 43 \(\pm\) 0.81 * & 50 \(\pm\) 0.51 *\$ & 54 \(\pm\) 2.50 *\$ \\ \hline \hline \end{tabular}  *  
*Moreover, these values are considered important predictors of performance; the higher the workload, the higher the level at which a rower will be able to perform [2]. In addition, the rise in core temperature follows, as expected, the intensity increment throughout the protocol, which can hinder aerobic power and endurance capacity, alongside attenuated oxygen delivery to the working muscles [17]. The displayed rise in both the respiratory coefficient and [La\({}^{-}\)] values with rowing intensity indicate a progressive recruitment of type II muscles fibers that are highly dependent on glycolytic energy supply [24; 37].