As I’ve been doing more coaching this season, one concern or comment I’ve heard from a lot of newer triathletes, especially those stepping up to the half ironman distance for the first time, is the fear of not making the time cutoffs. At a half ironman, how slow can you go? I had this concern with my Ironman, which led me to write this post. (Please note: neither of these are my recommendations in terms of paces to train at; these posts are intended to be a general gauge at which to see how close you are to general race cut-offs or how comfortable of a pad of time that you have). I figured I should write up a similar guide for the Ironman 70.3 distance, or the “half ironman.”
So I actually mapped it out, and I want to share the information! Each race is a little different in terms of its cutoff times, so use this as a guide but check your Athlete Guide for more specifics as to your race. I was looking at the 2017 Ironman 70.3 Steelhead Athlete guide when I wrote this. For your race, please check the most up-to-date Athlete Guide on the race website.
Ironman 70.3 – How Slow Can You Go?
You have to swim 1.2 miles in 1 hour and 10 minutes. Even if you start in an earlier wave, each athlete has the same amount of time or else they are disqualified. 1.2 miles in 1 hour and 10 minutes translates to a 3:37/ 100m pace. If you swim in a yards pool, then your slowest 100 pace can be 3:18/100yd — and you must be able to maintain this for 1.2 miles or 2112 yards. (Coaching tips: you should be comfortable swimming at a faster pace for shorter distances first. If you’re still working to achieve a 3:18/100yd or 3:37/100m pace, I’d recommend working with a coach to help get your swim technique and fitness to a place where you can easily swim faster than that before you build to the 1.2 mile distance.)
For a half iron distance race, the bike cutoff is 5 hours & 30 minutes after the final athlete enters the water. Let’s play it safe and assume that YOU were the last athlete to start. If you are in the absolute last swim start wave, you must complete the swim, T1, and the 56 mile bike within five and a half hours.
If you take the maximum swim time + 10 minutes in transition, then you have 4:10 to bike your 56 miles. That translates to a 13.44 mph. Keep in mind that you are still held to this time cutoff even if you have a mechanical issue or need to stop to fill bottles, so good training and preparation for the event should help you get to a solidly faster pace than that for your long rides!
Let’s continue with following the slowest possible paces. You started the swim last, took the maximum time there and also on the bike. (Again, please train smart and to the best of your capabilities so that you’re not planning to barely hit each of these cut0ff times!) And let’s suppose you took 10 minutes each in transition! Steelhead 70.3 this year has a final time cutoff of 8:30 for every single athlete.
At this point the “last racer in” race clock is at 5:40, so we have 2:50 left for our run. And that’s a 12:58 min/mile pace for the half marathon. And anyone who got off the bike before can complete it at a slower pace.
My goal in this is not to scare anyone, but to put the paces/speeds out there for the bare minimums. These are assuming you are taking all of your time on each of the disciplines. As a coach, I recommend that you make sure you’re comfortable swimming, biking and running around or above these speeds.
What should I do?
Gather up your training paces, or benchmark tests. Be honest with yourself about the Ironman and where you are in training:
- What was the speed of your average long ride?
- What about your average long run?
- What’s your average swim pace?
- What sport are you most nervous about?
- What can you control and work on to be faster? (This includes things like transitions, grabbing bottles or aid while on the bike and run without stopping, practicing how to change your flat tire more quickly, in addition to training to help improve your moving paces)
You can calculate out a few predicted finish times using online triathlon calculators. There are two ones I commonly go to – a simple one provided by Redline Triathlon Club, and a more complex race prediction calculator from QT2 Systems.
Play out the scenario with your conservative paces — remember what you do in training is likely what you’ll do on race day. So for me, I am predicting a more realistic timeline that I will share with friends and family of what I am thinking I’ll do – both in a best case scenario and also in the “less than ideal day”. Being transparent with my sherpa and spectating crew helps them to know when to expect to see me and to plan their day as well!Just how slow can you go in a half @IronmanTri ? Figure out if you'll finish before the cut-offs!… Click To Tweet
Interested in reading more about my half ironman race experiences?
- Ironman 70.3 Racine (2013) Race Report
- High Cliff 70.3 Triathlon (2014) Race Report
- Ironman 70.3 Racine (2015) Race Report
- Door County Half Iron (2017) Race Report