About Us

Since 2012, GlobalLimits had been organizing multi-stage races in Cambodia, Bhutan, Sri Lanka, and Albania. São Tomé is organized in 2020 especially for qualified runners.  Our goal is to combine running with local cultural appreciation – that is, all our race locations have spectacular historical backdrops and there are always opportunities to stay in local homes.   

Our team, including our volunteers and local partners, are experienced runners or event organizers; we have proven track records in organizing successful multi-stage races.

Our professional medical team specializing in wilderness and emergency medicine will provide you necessary high-standard medical treatments during the race week.


Stefan Betzelt/Germany - Founder and General Manager of GlobalLimits

Stefan was born and lives in Wiesbaden/Germany. He founded GlobalLimits in 2012. Stefan has a wealth of extreme racing experience, having participated in many of the most gruelling ultra races, such as Marathon des Sables, Les Foulees de la Soie, Himalayan 100Mile Stage Race, Racing the Planet Namibia and Desert Oman Raid. He also participated in about 20 city-marathons (PB 2:46) and successsfully climbed the Kilimanjaro and the Mount Aconcagua.

Stefan has visited more than 92 countries and learnt a great deal about different cultures and people. He now makes use of this experience to select outstanding and unique locations for the GlobalLimits races.

Stefan has worked as a managing director for some of the leading global financial institutions before he retired in 2004 to become a self employed financial and personnel consultant.

Stefan is also a member of the Curatoship of the Institute of Sports Medicine in Frankfurt/Germany.

Mario Machado, Lisbon/Portugal - Course Director

Mario, a physical Education teacher and international athletic coach, is the technical director of the Lisbon Half Marathon (30.000+ runners), the Portugal Half Marathon, the Lisbon Marathon and the organizer, technical director and controller of the race of various other high profile road races in Portugal and international trail races.

Since 2009 he is also the "Controller of the race" of the Marathon des Sables in Morrocco.

Mario is the publisher and director of "Spiridon-Portugal" running magazin since 1978.

He is also a very experienced runner himself. He just finished his 100th Marathon/Ultra at GlobalLimits Cambodia 2017.

Mario already served as a volunteer for the inaugural race in Albania in 2017 and in Cambodia 2018 as well as being the course director in Albania 2018 and 2019 and Sao Tome 2020.

Ledjo Hoxha, Tirana/Albania - Course Marker

Ledjo was born and lives in Albania. He has studied Political Science and now works for the Ministry of Defense in Albania. His passion about adventure leads to his journeys. He is a scuba diver, climber and also does a lot of adventure sports. He loves meeting new people and getting in touch with new cultures and is excited to have such an experience as Sao Tome.  

Ledjo already served at GlobalLimits Albania 2018 + 2019

Ryan Paterson, Denver/USA - Medical Director

Dr. Ryan Paterson attended the University of Vermont School of Medicine and completed his Emergency Medicine Residency and Fellowship in Wilderness/Altitude/Expedition Medicine at Denver Health Medical Center/University of Colorado. He also holds advanced certifications in Tropical Medicine from the London School of Tropical Medicine and Hygiene (DTM&H) and in Mountain Medicine (DiMM). He is a practicing Emergency Physician for Kaiser Permanente at St Joseph’s Hospital in Denver, Colorado.

Dr. Paterson serves as co-course director for the Wilderness Medical Society and Universities of Colorado and Utah’s Diploma in Mountain Medicine Course (DiMM). He is the current United States delegate to the International Society of Mountain Medicine (ISMM). Currently, Dr. Paterson is working, in partnership with CU South Denver to develop a Wilderness Medicine for Kids program utilizing an original curriculum. He also serves as medical director for No Barriers and another non-profit (Kolkata City Mission) working to establish sustainable development solutions in education, health, women’s empowerment, micro-enterprise and public-health for informal communities in and around Kolkata, India.

Ryan already was our medical director in Cambodia 2016, Bhutan 2017, 2018, 2019, Albania 2018, 2019, 2020 and Sao Tome 2020.

Frank Johansen/Denmark - Race Doctor

Frank participated in all of our current races Albania 2017, Bhutan 2019, Cambodia 2019 & São Tomé 2020, and now joins us as a race doctor. Not only is he a medical doctor, he also has a degree in sports & leisure. Beside practicing medicine he's a medical consultant at the department of sports at Aarhus University in Denmark. He has done research and written sports books on talent development. In addition he coached in a number of sports and volunteered at Olympic Games.

Frank has always loved being physically active and never far behind a ball. In his teens he was a scratch golfer. In his adult life he has combined his passion for sport with travel/adventure which have taken him to more than 100 countries. Many of which seen by foot, running marathons or ultra marathons. He was the first Dane to complete the seven continents in one calendar year which included destinations like North Korea, Tchad and the inaugural Hidden Treasure in Albania. He enjoys to meet people from different cultures and experience unique scenery, excited to be part of the Global Limits family as a medic.

Mafalda Iria, Portugal/Sao Tomé - Volunteer

Mafalda, Portuguese, is a veterinarian at Zuntapata - a lovely veterinary clinic by the sea, in São Tomé and Principe. She arrived in São Tomé in 2017, where she set up her clinic and AMA, an association that works for the safe of street animals, public health and food security.

Her biggest aspirations are her family (of two and four legs), nature and... sport, of course!

For 22 years she practiced ballet and rhythmic gymnastics, until her soul mate instilled her with a new passion: running.

Mafalda was lucky to meet the inspiring GlobalLimits Family in the first race in São Tomé at “The Hemisphere Crossing” in 2020, in which she participated for the first time, as a volunteer, and she hopes this will happen many times in the future.

Amy Paterson, Denver/USA - Volunteer

Amy is the mother of two active girls, married to Ryan Paterson, GlobalLimits' medical director. She works as an Elementary School Teacher. In addition, she volunteer coaches soccer and lacrosse for young girls in Denver. She has supported and volunteered for numerous running, cycling, and triathlons races.

 She was an All-American lacrosse player in high school and college and loves working as a team. She is truly inspired by athletes competing in ultra-marathons and is excited to volunteer. Amy loves to travel, be outdoors and is always up for an adventure.

Amy already served as a volunteer at GlobalLimits Albania 2018.

Martin Nobbs, Great Britain - Volunteer

Born in London, Martin is a retired Police officer, who now works in Wildlife control with the RAF. He has been running multi stage ultra races since 2008, his first step into these incredible adventures was in Brazil completing the Jungle Marathon. Further races include The Coastal Challenge Route of Fire and Rainforest Run, the Ultra Asia race in Vietnam, and GlobalLimits, Sri Lanka, Cambodia and Albania.

He loves being outside, and running in places where most of the world's population would never visit.

He is now volunteering because he likes helping people and pushing them to succeed in their goals

Joana Mendes/Portugal - Volunteer

Joana is a kindergarden teacher and a rhythmic gymnastics coach as well.

She discovered São Tomé in March 2021 and started immediately thinking about moving to this beautiful island.

For 23 years she practiced rhythmic gymnastics, and became a coach 7 years ago.

She will participate in the GlobalLimits Race for the first time as a volunteer and is very excited about it.

Stefan Schlett/Germany - Volunteer

Stefan is a life long adventurer and celebrates the art of extreme-sports since the age of 19. After school he worked 4 years as an retail salesman, before he joined the German army for 5 years as an paratrooper. The army service functioned as an exit from normal life and after that he never came back to a ordinary life. As a ‘freelance-adventurer‘ and freelance writer he was a Pioneer in extreme-sport in Germany. He was the first German participant in several events famous at the time in the ultra-scene (e.g. Western States Endurance Run, Badwater Race, Grand Raid, Sri Chinmoy 1300 mile run, Marathon des Sables, Tough Guy etc.) and made these events known in Germany through his publications. At the end of the 80s, he set a dozen German records in the street run, from the 6-day to the 1300-mile run, as well as in the deca triathlon (tenfold Ironman), which he would hold for a decade. At his most active times he practiced the following disciplines: ultrarunning, skydiving, mountain-climbing, triathlon, inline-skating, ice swimming, kayaking, staircase running, swimrun, obstacle races, mountain-biking.

Noteworthy Accomplishments:

- 507 Ultras + 209 Marathons in 67 countries, totally more than 2000 competitions in 97 countries

- Former World Records: Marathon and 50k on a cruise ship; treadmill – 111k in 11:11 hrs; Run Up automatic downhill-escalator – 21.403 stairs/5000 m altitude; Ultramarathon in the underground (700 m below the surface in a salt mine)

- First human to traverse 4 continents (three by foot, one by mountain bike) by human power, under competition rules: Trans-America-Footrace from Los Angeles to New York 1992, Trans-Australia-Footrace from Perth to Canberra 2001, Trans-Europe-Footrace from Lisbon to Moscow 2003, Tour d’Afrique from Cairo to Capetown 2005

- Climbing: highest mountains in 45 countries and 5 continents; highest mountain: Pik Lenin/7134 m in the Pamir Range

- 496 skydives all over the world, including one at the Northpole

- Travelling: roughly 120 countries travelled, 400 islands visited, 400 mountains climbed

Stefan already served as a volunteer in Albania 2020.

Tiziano Pisoni/Mucumbli Explore, São Tomé - Logistics & Infrastructure