Sosenka was known as one of the largest professional cyclists competing in Europe.

Standing 200 cm (6 ft 6+1⁄2 in) tall, he weighs 83 to 90 kg (183 to 198 lb) and rides a track bicycle with 190 mm (7.5 in) cranks.

For his 2005-hour record attempt, he used a custom carbon fiber bicycle manufactured by Francesco Moser cycles.

In 2006, he won the Czech Republic national time trial championships and following this the two-man time trial Duo Normand with Radek Blahut.

In June 2008, he tested positive for the banned stimulant methamphetamine and its metabolites during his national time trial championships, and received a suspension which ended his career.