Foster, who was part of the coxless four that won gold in Sydney, has been plagued by injury in recent seasons.

A recurring back problem almost cost the 31-year-old his Olympic place and he missed this season's World Championships with a knee injury that required surgery.

After initially announcing he would stay in training to compete at the Athens Olympics in 2004, Foster decided his body could take no more punishment.

"It had to happen sooner or later," said Foster.

"It's been on the cards. I think my body is trying to tell me something.

"It was a very difficult decision. Rowing has been my life for the last 12 years at least, and it's what I loved doing.

"But now I feel I'm better off looking forward and going into coaching rather than putting my body through the strain of the next three years."

Foster, who also won an Olympic bronze in 1996 as well as seven World Championships medals, has been awarded an Apprentice Coach Scholarship by the Amateur Rowing Association.

The new initiative, designed to help top rowers make the step into high performance coaching, is funded by lottery money.

Foster will be working with national squad athletes, guided by chief coach Jurgen Grobler.