Jess Tri 1

Everything You Need To Know About Body Marking For Your First Triathlon

On the morning of my first triathlon, I had no idea what to do or where to go. I had the classic “deer in headlights” expression on my face but I didn’t notice it at the time because I was too busy trying to calm the butterflies in my stomach. I was a nervous newbie… and it showed.

Everything You Need To Know About Body Marking For Your First Triathlon |

I was stopped on my way to the transition area by a guy with a supersized Sharpie. He wrote my race number on my arms and my age on my left calf.

As soon as I was “marked”, I felt a surge of confidence and the butterflies disappeared… at least until I headed to the beach for the swim start. Even though the race hadn’t started yet, I already felt like I was a triathlete, and I had the body markings to prove it.

I quickly noticed another benefit of having your age on your leg. It helped me identify whether the hunky boys I kept seeing were my age. 🙂

There has been a lot of talk about whether having your age on your calf is a good thing or not. Some people really don’t appreciate having to make their age public knowledge. Some people don’t write their actual age on their leg. Others like it because it helps them see who their age group competition is.

I fall somewhere in the middle. I don’t mind it, and I don’t use it to size up my competition since I usually race for fun, but it sure is discouraging when I’m passed on the bike and run by triathletes who have 65 or 14 written on their calves.

Did you know that there is no rule in the USAT rule book that says you have to have your age on your calf?! It’s true! Plus a lot of triathletes are wearing Compression Socks to race so that defeats the purpose of the age.

However, almost all races still do the age on the calf marking. Surprisingly, it wasn’t required for our last triathlon, but luckily Davey and I brought our own Sharpie and so we wrote our ages on our calves because we like it when, after the race, people ask “What’s the number on your leg?”, and we answer, “Oh, that’s just from our TRIATHLON!”

And speaking of age, Davey’s birthday is next week and to celebrate we’re having an AWESOME GIVEAWAY on TUESDAY including some sweet TwoTri swag as well as a few of his favorite training items. It’s gonna be RAD. You won’t want to miss it!

Everything You Need To Know About Body Marking For Your First Triathlon |


The reason for body marking is so that race officials, volunteers and photographers can identify you for photos, starting groups, penalties and, God forbid, a medical emergency. Here are a few things to know about body marking:

  • Don’t put sunscreen on before getting marked because the number will rub right off. We like to use a spray sunscreen after we’re marked.Everything You Need To Know About Body Marking For Your First Triathlon |
  • Your race number is written vertically on your arms and your age is written horizontally on your left calf. Sometimes they write your age on both calves.  Just go with the flow of your race.
  • Some races will also write a “B” for Beginner on your right calf or a “C” for Clydesdale and an “A” for Athena.
  • More and more races are using Tri Tat’s which are temporary tattoos with your numbers instead of using a Sharpie. This saves time on race day since you can apply your tattoo the night before.
  • You apply Tri Tat’s the same way you did when you were a kid and had a whole arm full of ballerinas, dinosaurs or Disney characters. (If you’ve never used a temporary tattoo, there is usually application instructions on the back side of the tattoo)
  • To remove the temporary tattoo, you could scrub your arm till the skin is raw or simply use baby oil, coconut oil, rubbing alcohol or nail polish remover for a gentler approach.
  • However, we recommend darkening your race number with a Sharpie when you get home and wearing short sleeves the next few days so that everyone knows you’re a TRIATHLETE, especially if it’s your first triathlon! (I may or may not still do this after every race, haha!)
  • If you’re using our Race Day Checklist, then you’ll know to pack a black Sharpie just in case your race doesn’t have people there to do the body marking for you.
  • Worried about whether you’ll be able to find the body marking station on the morning of your race? There will probably be an obvious line of other triathletes waiting to get marked. Go stand on that line.

Everything You Need To Know About Body Marking For Your First Triathlon |

  • The exact location of your race number and age varies from race to race.
  • Make sure you have your timing chip with you or already on your ankle. If we get our timing chip at packet pickup the day before the race, we’ll put it on our ankle FIRST THING in the morning so we don’t forget it. Sometimes, you’ll pick up your timing chip when you arrive at the race… put it on your ankle right away. You don’t want to loose that thing!
  • Don’t forget to apply your race numbers to your helmet, bike, swim cap (if applicable), and pin your race bib to your shirt. The most important thing is to make sure your number is visible at all times and that your bib faces front during the run.

Everything You Need To Know About Body Marking For Your First Triathlon | Wear your race numbers proudly and let them remind you that you are AWESOME. You are a TRIATHLETE! Other body markings of a triathlete include dumbbell imprints, faded race numbers, sweaty shirts and goggle marks. The marks of a triathlete: dumbbell imprints, faded race numbers, sweaty shirts and goggle marks |

Still confused? Watch this video of us getting marked before our NashVegas Tri last year:



About Author

Trainer DaveyTrainer Davey is an Orange County personal trainer at heart, but has since moved to Nashville and taken on the new challenge of triathlon training. Of course, he misses his home of Surf City...but Music City ain't so bad either!View all posts by Trainer Davey →

  1. Aaron VanWieren
    Aaron VanWieren08-23-2013

    You should have probably also lumped the timing chip pick up into this post. Most races require you have your bib with you when you get your time chip and a few require it when you get body marked, does not hurt to carry this with you before the race. I have had both happen in my three races. I have never had to worry about figuring out where marking is as most triathlons choose young hyper over energetic girls to do body markings, so finding it has been easy. Thanks for a good post.

    • Jess Anderson
      Jess Anderson08-23-2013

      Good idea, Aaron! I’ll add that to the post. Thanks for stopping by!

  2. Axel (@apkussma)
    Axel (@apkussma)08-23-2013

    My birthday is in September, but all the races I’ve done specify your age group according to your age at the end of the year (12/31). I haven’t seen any Canadian triathlons past September, so I usually get bodymarked my current age + 1 at most races. I did my first race in compression socks recently and my age was obscured… I did see someone else who had the foresight to get bodymarked on the back of their knee instead… bet that tickled!