Dumoulin, regarded as the biggest threat to Chris Froome for the time trial on the hilly Grumari circuit on Aug. 10, posted a video on Twitter of him back on his bike.
— Tom Dumoulin (@tom_dumoulin) July 26, 2016
The 25-year-old faces a race against time to be fit for Rio, although the break was clean and there was not thought to be any damage to the wrist.
"It’s was a huge disappointment to drop out of the Tour. After the crash I directly knew something was wrong, Rio was in danger,: Dumoulin said.
"The first x-rays confirmed my feeling. I had additional examinations at the hospital which confirmed that the fracture was a clean one.
"The belief that Rio was still possible started to become stronger yesterday after I went to fit my brace and I carefully restarted my training with an easy test ride. It went well and I am just really happy to be able to ride the bike again so soon."
"The preparation went a little bit different than planned. Instead of recovering from a complete Tour and having a relaxed time at home doing the last training before going to Brazil, I am now going for check-ups to the hospital and fitting braces.
"However I have a good medical support with now almost two weeks to go, the brace and special exercises we’ll go for it."