Canada 's Andre De Grasse may be the top challenger to Bolt 's hopes of another Olympic three - peat .
Usain Bolt , obviously , is favoured after breezing to victory in the 100m and jogging through the 200m opening rounds .
Canada 's Andre De Grasse may be the top challenger to Usain Bolt 's hopes of another Olympic three - peat .
Usain Bolt , obviously , is favoured after breezing to victory in the 100m and jogging through the 200m opening rounds .