The 49-year-old man sustained a head injury following the incident at about 09:00 on the Loan Footpath, at its junction with Fergus Avenue.
He was taken to the Western General where his condition is now considered to be serious.
Police Scotland are trying to trace the cyclist, who did not swap details with the jogger at the time.
Sgt Neil Inglis said: "We're eager to trace the cyclist, described as a man in his early 20s, and any witnesses, as soon as possible in the hope that they can help us establish the full circumstances surrounding this incident."
Police are also appealing for witnesses to a collision between a motorbike and car in East Calder.
A Kawasaki motorbike and a Kia Ceed collided at about 17:15 on Friday on the A71 junction with the B7031 Camps.
The A71 was closed for about an hour while the road was cleared.
A 41-year-old man was taken to the Edinburgh Royal Infirmary with serious injuries, which are not thought to be life-threatening.
A jogger has been seriously injured in a collision with a bicycle in Livingston.