AUTHOR=Sheykhlouvand Mohsen , Arazi Hamid , Astorino Todd A. , Suzuki Katsuhiko 

TITLE=Effects of a New Form of Resistance-Type High-Intensity Interval Training on Cardiac Structure, Hemodynamics, and Physiological and Performance Adaptations in Well-Trained Kayak Sprint Athletes

JOURNAL=Frontiers in Physiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2022.850768

DOI=10.3389/fphys.2022.850768

ISSN=1664-042X

ABSTRACT=<p>This study examined the effects of a resistance-type high-intensity interval training (RHIIT) matched with the lowest velocity that elicited <inline-formula><mml:math id="INEQ1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover accent="true"><mml:mtext>V</mml:mtext><mml:mo>.</mml:mo></mml:mover></mml:math></inline-formula>O<sub>2peak</sub> (100% <italic>v</italic><inline-formula><mml:math id="INEQ2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover accent="true"><mml:mtext>V</mml:mtext><mml:mo>.</mml:mo></mml:mover></mml:math></inline-formula>O<sub>2peak</sub>) in well-trained kayak sprint athletes. Responses in cardiac structure and function, cardiorespiratory fitness, anaerobic power, exercise performance, muscular strength, and hormonal adaptations were examined. Male kayakers (<italic>n</italic> = 24, age: 27 ± 4 years) were randomly assigned to one of three 8-wk conditions (<italic>N</italic> = 8): (RHIIT) resistance training using one-armed cable row at 100% <italic>v</italic><inline-formula><mml:math id="INEQ3" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover accent="true"><mml:mtext>V</mml:mtext><mml:mo>.</mml:mo></mml:mover></mml:math></inline-formula>O<sub>2peak</sub>; paddling-based HIIT (PHIIT) six sets of paddling at 100% <italic>v</italic><inline-formula><mml:math id="INEQ4" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover accent="true"><mml:mtext>V</mml:mtext><mml:mo>.</mml:mo></mml:mover></mml:math></inline-formula>O<sub>2peak</sub>; or controls (CON) who performed six sessions including 1-h on-water paddling/sessions at 70–80% maximum HR per week. Significant increases (<italic>p</italic> &lt; 0.05) in <inline-formula><mml:math id="INEQ5" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover accent="true"><mml:mtext>V</mml:mtext><mml:mo>.</mml:mo></mml:mover></mml:math></inline-formula>O<sub>2peak</sub>, <italic>v</italic><inline-formula><mml:math id="INEQ6" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover accent="true"><mml:mtext>V</mml:mtext><mml:mo>.</mml:mo></mml:mover></mml:math></inline-formula>O<sub>2peak</sub>, maximal cardiac output, resting stroke volume, left ventricular end-systolic dimension, 500-m paddling performance were seen pre- to post-training in all groups. Change in <inline-formula><mml:math id="INEQ7" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover accent="true"><mml:mtext>V</mml:mtext><mml:mo>.</mml:mo></mml:mover></mml:math></inline-formula>O<sub>2peak</sub> in response to PHIIT was significantly greater (<italic>p</italic> = 0.03) compared to CON. Also, 500-m paddling performance changes in response to PHIIT and RHIIT were greater (<italic>p</italic> = 0.02, 0.05, respectively) than that of CON. Compared with pre-training, PHIIT and RHIIT resulted in significant increases in peak and average power output, maximal stroke volume, end-diastolic volume, ejection fraction, total testosterone, testosterone/cortisol ratio, and 1,000-m paddling performance. Also, the change in 1,000-m paddling performance in response to PHIIT was significantly greater (<italic>p</italic> = 0.02) compared to that of CON. Moreover, maximum strength was significantly enhanced in response to RHIIT pre- to post-training (<italic>p</italic> &lt; 0.05). Overall, RHIIT and PHIIT similarly improve cardiac structure and hemodynamics, physiological adaptations, and performance of well-trained kayak sprint athletes. Also, RHIIT enhances cardiorespiratory fitness and muscular strength simultaneously.</p>