Some 30,000 runners will descend on San Antonio to run in the 5th-annual Rock 'N' Roll Marathon this weekend.

Many are veteran marathon runners, but there are many who are new to the 13.1-mile half-marathon or the full 26.2-mile marathon trip around San Antonio, so there are things that runners need to be aware of as they lace up their shoes and hit the road.

Longtime coach and co-founder of the Rock 'N' Roll Marathon, Tracy Sundlun, keeps it simple

"You need to run within your (limits)," Sundlun said. "Let’s not get crazy."

Beginners and veterans alike have been training for months -- some even years -- and the main thing they need to remember, Sundlun said, is to keep doing what they have been doing.

"You don’t want to do anything different on race day than you do any other day," Sundlun said.

Dr. David Gude, with Texas Med Clinic, shared a few things to do -- and a few things not to do -- for runners/ had a few ‘to do’ and ‘not to do’ things for runners.

  • The day (or night) before race, stay well hydrated and rested

  • During the race, consume 6 to 8 ounces of water every 20 minutes or 24 ounces every hour with calories and salt source or sports drink

  • No new foods, no new drinks, no new shoes or shorts

  • No Advil or Aleve leading up to race (they could cause kidney damage); Tylenol is OK

  • Do not over-hydrate

  • Have a blast

There is one simple objective for all runners.

"That’s the goal: finish and have a good time," said marathoner Jody Orozco.