AUTHOR=Kårström Andreas , Swarén Mikael , Björklund Glenn 

TITLE=Discrepancies in internal and external training load measurements during low-intensity biathlon training

JOURNAL=Frontiers in Sports and Active Living

VOLUME=6

YEAR=2024

URL=https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2024.1455900

DOI=10.3389/fspor.2024.1455900

ISSN=2624-9367

ABSTRACT=<sec><title>Purpose</title><p>This study aimed to differentiate external and internal training loads during on-snow biathlon training by adding an accelerometer-derived metric.</p></sec><sec><title>Methods</title><p>Eleven adolescent athletes were fitted with a combined heart rate (HR) and accelerometer to be worn during all training sessions. Duration, HR, training impulse (TRIMP), and average net force (<inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="IM1"><mml:mi>A</mml:mi><mml:mi>v</mml:mi><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi>N</mml:mi><mml:mi>e</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula>) were used as training variables. All training was divided into either low-intensity training (LIT), or high-intensity training (HIT) based on reported intensity. The training was further categorized as training without any shooting practice (NS) or as a combination of skiing and shooting (COMB). Duration, HR, TRIMP, and <inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="IM2"><mml:mi>A</mml:mi><mml:mi>v</mml:mi><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi>N</mml:mi><mml:mi>e</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> were analyzed in a linear mixed model for the different training modalities.</p></sec><sec><title>Results</title><p>All training was similar in duration for LIT and HIT sessions (<italic>p</italic> = .0521) and NS and COMB sessions (<italic>p</italic> = .988). TRIMP did not differentiate between LIT or HIT training (<italic>p</italic> = .350) or for NS compared to COMB (<italic>p</italic> = .298). While <inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="IM3"><mml:mi>A</mml:mi><mml:mi>v</mml:mi><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi>N</mml:mi><mml:mi>e</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> decreased during COMB compared to NS during LIT sessions (<italic>p</italic> &lt; .001) it remained similar during HIT training (<italic>p</italic> = 1.00).</p></sec><sec><title>Conclusion</title><p>The study’s findings indicated that there were no notable differences in internal training load (TRIMP) when comparing various training intensities and modes. However, the type of training had a significant impact on <inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="IM4"><mml:mi>A</mml:mi><mml:mi>v</mml:mi><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi>N</mml:mi><mml:mi>e</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula>, especially leading to a decrease during COMB sessions under LIT conditions. Incorporating an external load metric could offer a fresh approach when prescribing and evaluating training, providing deeper insights into the training load.</p></sec>