Sin's Story

Sin's Past as a Top Athlete

Sin, 20 years old, held by his teammates Sascha Schneider on the right side and Damiano Curcio on the left winning the German Championship (DKV) in Shotokan Karate Juniors Kumite Team 1996.

International high-performance athlete and experienced executive with over 25 years of expertise in Sales, Management, and Coaching. I am a Cyber Security consultant, the developer of the BrainSales® method, and the founder of Prime Telecom and WorthDay.

When I'm not optimising biological efficiency, I'm a passionate food nerd, a dog owner, a father, and a singer who just hit a new level of 'proper' singing (while still practicing my guitar skills!).

"I will inspire 1,000,000 people by 2035. I can see it, I have been there and it will happen."

Sin, WorthDayer One

Sin defeated the reigning European Champion but was ultimately beaten by the eventual tournament winner. In the bronze medal match, he narrowly lost despite an early lead. This marked Sin's second appearance representing Germany, wearing the federal eagle on his chest.

Sin, pictured next to his Sensei Bernd Weinreich before the Junior State Championship finals in 1996, Kumite +75 kg.

• 2001: Winner, International Neckar Cup (Individual +80kg).
• 1999: Vice German Champion, Karate Bundesliga (Shintaikan Villingen).
• 1996: German Champion (Kumite Team), National Championships.
• 1996 - 2003: Baden-Württemberg State Champion (Individual +80kg).
• 1995 – 1996: Professional Athlete, German Armed Forces Sports Promotion Group (Sonthofen).
• 1995: Vice World Cup Winner (Kumite Team), Pori, Finland.
• 1995: Vice CISM Military European Champion (Kumite Team), Ostia, Italy.
• 1994 - 1997: Induction into the German Juniors National Team DKV (Individual +80kg and Team).

Sin, 20. Pictured with his trophies in his former Karate Dojo Nippon in Eislingen, Germany.

• Master of Business Administration (MBA): General Management.
• Certification as ICO CISIS12® Professional
• Certification as CISIS12® Information Security Officer
• TÜV Certification as NIS2 Expert
• TÜV Certification as External Data Protection Officer
• Various Training Programmes:
  Advanced education from Vodafone, Telekom, O2, ecotel, SWI GmbH, LocateRisk, BlackShield, TÜV-Akademie on digitalization and security topics.
• Alchimedus® Business Coach
• INtem Limbic® Sales Trainer
• Group Dynamics Trainer
• INtem® Business and Management Coach

• 2021: Winner of the Private Karaoke Competition in the Category "Serbian Folk Song" 😉
• 2014: International German Training Prize in Silver (BDVT e.V.) with BrainSales GmbH for "BrainSales - Gehirnfreundlich verkaufen".
• 2013: International German Training Prize in Silver as part of the INtem® trainer team for "Emotionalisierung im technischen Vertrieb".
• 2012: INtem Platinum Award for Excellence in Sales and Management Coaching.

International Silver Training Prize Award Ceremony 2014

Evelyn and Sinisa Trisic are presented with the Silver Training Award in Cologne for their concept "BrainSales® - Brain-friendly Selling" (which increased the closing rate for the participating mechanical engineers in Germany by 50%).

Helmut Seßler, Sinisa Trisic, and Marion Seßler at the victory celebration.

"Helmut and Marion were my coaches and mentors. Remarkably, all three of us, Marion, Helmut and I spent our professional careers in banking before starting our paths as trainers. I owe my successful years as a self-employed coach and trainer to them. Sadly, Helmut passed away recently. Helmut, I dedicate this award to you in eternal gratitude."

Sin explains the BrainSales® Method which is one important scientific cornerstone among others

To inspire 1,000,000 people to use the WorthDay App as their personal Compass for clarity and their essential Logbook for consistency, growth, and lasting happiness—turning every 24 hours into a life worth living.

Sin's Story: The Sign and the Mission

Guinness World Record (GWR) Attempt:
Scheduled for April 2026, Sin at the age of almost 51 will perform 2,000 Bear Crawls in a single session. This milestone serves as the ultimate physical validation of the WorthDay system, proving that systematic consistency leads to peak performance at any age.

UPDATE

The Guinness World Records committee has rejected my application.

When I think back to late 2025, when I was still proud of 200 bear crawls and collapsed at 400 — and now, despite a wrist injury and a forced break, I received this rejection at 1,200 — it doesn't make me sad. I will keep crawling on all fours and already have a new idea that might lead me to apply for another world record attempt.