She was born in the village of Oshali in the Oshana Region. She is a five-time winner of the Two Oceans Half Marathon and holds the current record of 01:10:29. Johannes made her international debut at the 2005 IAAF World Cross Country Championships, where she finished 80th in the women's long race. She came fifth in the half marathon of the 2007 Summer Universiade and completed the same feat at the 2007 All-Africa Games. She also ran in the Dublin Marathon that year, coming in fourth place. Johannes ran a qualifying time of 2:33:06 hours at the Seoul International Marathon in March 2008, qualifying her for the 2008 Summer Olympics. In the Olympic marathon race she placed fortieth in the rankings. She again represented her country on the global stage at the 2009 World Championships in Athletics, but finished 56th in a slow time of 2:50:19 hours. She rebounded at the Dublin Marathon, finishing as the runner-up. The following year she had one of her best international performances, coming 16th at the 2010 IAAF World Half Marathon Championships. She was the 2011 winner of the Dublin Marathon in a personal best and Namibian national record run of 2:30:37 hours. That year she won two bronze medals for Namibia, first in the marathon at the 2011 Military World Games and then in the half marathon at the 2011 All-Africa Games. She knocked more than three minutes off her then personal best at the 2012 Vienna Marathon, taking third place behind Olga Glok. At the 2012 Summer Olympics, Johannes knocked more than a minute off that personal best, finishing in 12th with a new best of 2:26:09 – a Namibian record. Her third and final marathon outing of 2012 came in Dublin, but she was somewhat slower and came sixth in a time of 2:35:01 hours. She entered the 2013 Tokyo Marathon and finished in under two and a half hours, taking sixth place. She was chosen to represent Namibia in the marathon at the 2013 World Championships in Athletics, but failed to finish. At the start of 2014 she ran 2:28:27 hours for third place at the Seoul International Marathon. At the 2014 Commonwealth Games, she was leading the marathon, before an injury caused her to slow. She finished in 5th place. Helalia won Namibia's second gold medal at the Commonwealth Games 2018 when she won the women's marathon. Johannes completed the 42,2 km marathon in a time of 2 hours 32 minutes 40 seconds to finish well ahead of second-placed Lisa Weightman of Australia while another Australian, Jess Trengrove won bronze in 2:34:09. Johannes was the first Namibian woman to win a Commonwealth gold medal. Her husband, Japhet Uutoni, also won a gold medal for Namibia in boxing at the 2006 Commonwealth Games. In 2019, Joannes broke three Namibian records. She broken the Namibian marathon record to win the Nagoya Marathon in a time of 2:22:25. She then broke the Namibian half-marathon record in April at the Two Oceans Half Marathon in Cape Town, running a winning time of 1:10:30. She then proceeded to break the 10 km record in Port Elizabeth with a time of 31.50. In September, she achieved her greatest career landmark by earning a medal at the Athletics World Championships, for her third place in the Marathon.
