Jäkle began his career as a Nordic combined athlete and was there in the national team's C-team until 1990. Because of the reunification , he was removed from the squad in favor of younger athletes. After a year break, he joined the Intercontinental Cup in 1992 as a special jumper. A victory in Oberwiesenthal secured him admission to the B-squad of the special jumpers. In 1994, with a 6th place in Bischofshofen, he qualified for the Olympic Games in Lillehammer , where he was team Olympic champion together with Jens Weißflog , Dieter Thoma and Christof Duffner . At the Nordic World Ski Championships in 1995 in Thunder Bay , the German team won the silver medal with Jäkle. Two years later, at the 1997 World Cup in Trondheim , the German team won bronze with Jäkle, Duffner, Thoma and Martin Schmitt . 1998 was finally the most successful year in Jäkel's career: team silver at the Olympic Winter Games in Nagano , German master on the normal hill , German master with the team and a second place in the Four Hills Tournament in Bischofshofen. After the 2001/2002 season he ended his active career as a ski jumper. He started a total of 165 times in the World Cup .
In 1994 he received the Silver Laurel Leaf together with Jens Weißflog and Dieter Thoma.
In the Olympic seasons he was a sergeant in the sports promotion group Todtnau of the Bundeswehr am Feldberg ( Todtnauer Hütte ).
Jäkle, who is also called Jackson , is a trained communications electronics engineer . He has been married since 2001 and has a son and a daughter. In addition to ski jumping, he spent a long time doing motocross with a Yamaha YZ 250. In October 2004, however, he broke both legs in a fall. He was badly broken into pieces and had to work hard to be able to walk again. Today he is a teacher for technology and handicrafts in his home town of Schonach and works as a junior trainer.
Jäkle is married to Ms. Martina and their daughter Anna is also active as a ski jumper and Nordic combined athlete. His son Jonas is also active as a combined athlete in the Alpine Cup.