Hormonal Response to Incremental and Continuous Exercise in Cyclists with Left Ventricle Hypertrophy

Area of Science:

• Exercise physiology
• Endocrinology
• Cardiology

Background:

• Elite cyclists exhibit varying cardiac dimensions, including left ventricle hypertrophy (LVH).
• Hormonal responses to different exercise types (incremental vs. continuous) in athletes with and without LVH are not fully understood.
• The relationship between cardiac adaptations and exercise-induced hormonal changes requires further investigation.

Purpose of the Study:

• To compare the effects of incremental exercise (IncEx) and continuous exercise (ConEx) on key hormones (IGF-1, GH, T, C) in elite cyclists.
• To determine if increased cardiac dimensions (LVH) influence these hormonal responses.
• To explore the link between cardiac biomarkers, hormone levels, and cardiac structure in cyclists.

Main Methods:

• Thirty elite cyclists were divided into two groups: those with LVH and a control group (CG) without LVH.
• Participants underwent IncEx tests to determine maximum power (Pmax) and VO2max, followed by ConEx tests at determined intensities.
• Serum concentrations of IGF-1, GH, testosterone (T), and cortisol (C) were measured before and after exercise protocols.

Main Results:

• Both IncEx and ConEx significantly affected serum IGF-1 levels, with a notable interaction effect in the LVH group.
• Cyclists with LVH exhibited higher post-exercise testosterone levels compared to the CG.
• Continuous exercise led to significantly higher testosterone levels than incremental exercise in both LVH and CG groups.
• A strong positive correlation was found between the post-exercise testosterone/cortisol ratio and left ventricular mass index in the LVH group.

Conclusions:

• Both incremental and continuous exercise stimulate significant increases in anabolic factors like testosterone.
• Continuous exercise appears to elicit a more pronounced testosterone response compared to incremental exercise, irrespective of LVH status.
• Regular incremental exercise may promote beneficial cardiac adaptations through enhanced anabolic factor concentrations, suggesting a potential advantage over continuous exercise at constant intensity for cardiac health.