Former world champion speed skater Nicole Begg is back on eight wheels and ready to race for the first time in 18 months.

The 25-year-old has not been able to do any sort of strenuous exercise, yet alone race, since 2011 as she battled undiagnosed phrenic nerve damage, which is the nerve which controls the diaphragm and spinal cord. Just a gentle jog would leave her breathless.

"The only thing I could do (to exercise) was walk which is quite frustrating when you're so used to being able to run.

"It [time] has gone quicker than expected because it wasn't like I had a diagnosis and a doctor said ‘you'll be out for 18 months'."

Begg went for a tentative skate for the first time just before Christmas and two weeks later got the all clear to commence training again.

Begg has spent three weeks on skates, but has already broken national records over sprint distances in training.

Her quick resurgence was something she attributed to muscle memory - effectively her body remembers how to skate fast.

After originally targeting a return to competition in February, Begg made herself a starter for the Tour of Timaru which gets under way today.

She said she would not have entered if she did not think she could win the four-day event.

"It would be frustrating, now that I know my body can handle it, to sit on the sideline and watch.

"After day one my body might be [tired] like I'm over it but I think I can handle it as long as I look after myself and put the right fuel in.

"I don't expect to win every race but I would like to win the overall [A grade] title."

Begg said her biggest competition was likely to come from South Canterbury Skating Club teammates.

"In the sprints, Emily van der Heyden is going really well and she did a personal best in the 300m time trail (on Tuesday).

"Judah Kelly is younger but she is quite a smart racer, while in the distance events, Stephanie Challis from Upper Hutt will be right there."

Begg said she knew she would have to race smarter than she usually did at a national level to prevail but she was confident her comeback would be a success.

- © Fairfax NZ News