• Sams, Lauren Eleonore
• Schüttler, Dominik
• Hamm, Wolfgang
• Brunner, Stefan
• Bauer, Axel
• Krammer, Simone
• Stülpnagel, Lukas Von

Abstract

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Assessing lactate (LT) or anaerobic thresholds (AT) in athletes is an important tool to control training intensities and to estimate individual performance levels. Previously we demonstrated that ECG-based assessment of cardiac repolarization instability during exercise testing allows non-invasive estimation of AT in recreational athletes. Here, we validate this method in professional and amateur team sports athletes.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We included 65 team sports athletes (32 professionals and 33 amateur athletes; 51 men, 14 women, mean age 22.3 ± 5.2 years) undergoing a standardized incremental cycle exercise test. During exercise testing a high-resolution ECG (1000 Hz) was recorded in Frank-leads configuration and beat-to-beat vector changes of cardiac repolarization (dT°) were assessed by previously established technologies. Repolarization-based AT (AT<jats:sub>dT°</jats:sub>) was estimated by its typical dT°-signal pattern. Additionally, LT was detected in accordance to methods established by Mader (LT<jats:sub>Mader</jats:sub>) and Dickhuth (LT<jats:sub>Dickhuth</jats:sub>).</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>All athletes performed exercise testing until exhaustion with a mean maximum workload of 262.3 ± 60.8 W (241.8 ± 64.4 W for amateur athletes and 283.4 ± 49.5 W for professional athletes). Athletes showed AT<jats:sub>dT°</jats:sub> at 187.6 ± 44.4 W, LT<jats:sub>Dickhuth</jats:sub> at 181.1 ± 45.6 W and LT<jats:sub>Mader</jats:sub> at 184.3 ± 52.4 W. AT<jats:sub>dT°</jats:sub> correlated highly significantly with LT<jats:sub>Dickhuth</jats:sub> (<jats:italic>r</jats:italic> = 0.96, <jats:italic>p</jats:italic> &lt; 0.001) and LT<jats:sub>Mader</jats:sub> (<jats:italic>r</jats:italic> = 0.98, <jats:italic>p</jats:italic> &lt; 0.001) in the entire cohort of athletes as well as in the subgroups of professional and amateur athletes (<jats:italic>p</jats:italic> &lt; 0.001 for all).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>AT<jats:sub>dT°</jats:sub>, defined by the maximal discordance between dT° and heart rate, can be assessed reliably and non-invasively via the use of a high-resolution ECG in professional and amateur athletes.</jats:p></jats:sec>

Topics

• impedance spectroscopy
• size-exclusion chromatography