The Paralympian was spotted training at the Alice Lane Virgin Active gym in Sandton on a Sunday.
According to TV producer Johan Stephan, who bumped into Oscar in the parking lot, the athlete was "soft-spoken".
"You could see he was a broken man. I asked to take a picture with him and he kept saying 'God bless, God bless'," Johan, who also manages the K2 Twins, says.
Apparently Oscar has trained at the gym a couple of times over the past months, usually on a Sunday.