Giannis was born in 1969 in Athens, Greece. He has been involved in sports like soccer, basketball, swimming and running from a young age. For the past 5 years, he has worked as a full-time coach for endurance sports and is committed to improving his coaching skills. He has over 25 years of experience in triathlon, having competed in over 200 races himself and coached over 100 athletes. He holds several coaching certifications and has a background in chemistry, sports management, business administration and communications.