Which hormones are listed as vital to athletic development?

• A. Testosterone, insulin-like growth factor, and human growth hormone
• B. Estrogen, cortisol, and adrenaline
• C. Thyroid hormone and melatonin
• D. Prolactin and oxytocin

Answer: (A)

Athletic development relies on anabolic signals that drive muscle growth, repair, and adaptation. The trio of testosterone, IGF-1, and growth hormone is central because testosterone boosts muscle-protein synthesis and recovery, growth hormone promotes tissue growth and stimulates IGF-1 production, and IGF-1 directly drives muscle hypertrophy and satellite-cell activity. Together, they create an environment that supports gains in lean mass, strength, and performance. Other listed hormones influence metabolism, stress, sleep, or reproduction, but they are not the primary drivers of athletic development.