Ironman Swim Distance (In A 25 Yard Pool)

Getting to an area for open water swimming is one of the biggest hurdles to proper triathlon training. For many athletes, ourselves included, that means instead doing a lot of training in a pool.

Since our local pool is a typical short course format training requires knowing some quick conversions. First and foremost, how long is an Ironman swim in yards?

A full ironman distance swim is 4224 yards, or 169 lengths of a 25 yard pool. This equates to 2.4 miles, which is the official Ironman posted swim distance. As a general rule it is good to be comfortable with whatever distance you plan to swim, and for shorter races being able to do 2-3 times the distance goes a long way in making race day feel easy. For longer distances, like an Ironman, going too much over the distance is not always needed, but doing so at least once in a low intensity training effort will give you a huge mental boost.

Triathlon DistanceSwim Distance (yards)Pool Lengths (25 yard Pool)
Sprint (Varies)820 yards (750 meters)33 lengths
Olympic1640 yards (1500 meters)66 lengths
Half Ironman (70.3)2112 yards (1.2 miles)85 lengths
Ironman (140.6)4224 yards (2.4 miles)169 lengths
Annoyingly the distances for each style of triathlon vary. Ironman, as an originally American event, uses a measurement in miles. For many events though the distance will also be dictated by the logistics of the course and it is common to have custom distances. In addition, even the same course will be different depending on the water temperatures, currents, waves, and transition area location.

Are Triathlon Swim Distances Accurate?

While this measurement seems exact there are a few reasons to take it only as a guide. An Ironman distance pool swim is NOT the same as an open water swim. Although some people do self-guided workouts of the Ironman distance, we have yet to see a formal race that does a swim of this length in a pool!

The first, and more meaningful reason to take the measurement of a triathlon swim as a guide only is because course conditions make it difficult to have a uniform course. Ocean swims have waves to surf or push you back, rivers have currents to push you off course, and even placid lake swims have crowd of people and present challenges with course sightings.

A typical athlete will swim anywhere from 2-10% longer than the course. It’s not uncommon for swimmers GPS watches to report them swimming as much as 2.75 miles (4840 yards or 193 lengths of a 25 yard pool). We have found that in an published Olympic distance (1500 meters) we swam as much as 2000 meters if our watch is to be believed, a full 33% more than the race intended. Much of this is simple watch inaccuracy.

Also you must consider that when publishing metric distances the Ironman distance is rounds off the 2.4mi to km conversions to both 3.8 or 3.9km. A 0.1km difference is 100meters or 109yards (4 lengths of a 25 yard pool). Going back and forth between conversions will certainly create some rounding errors.

Why Can You Swim Faster in a Pool?

Race day of a triathlon can have many benefits that lead to a faster swim. The added buoyancy of a wetsuit will speed you up, proper drafting off faster swimmers, as well as tapering and the general adrenaline of a race often leads to good swims. Even so, some athletes find their times in open water to be much slower. Most trackers will report swim average paces in time per 100 yards (or 100m).

Swimmers with good flip turns and powerful push offs may realize that a boost every 25 yards can take their average swim times down by 5-10 seconds per 100 yards. These mini breaks at each wall will ruin a good rhythm of your swim, but overall many folks find that wall push offs help their overall time.

The major issue with open water swimming compared to a pool though, is the accuracy of the line you are swimming. A triathlon course is measured to be a specific line but the reality is that swimming in a straight line is very difficult. An imbalance in your catch or rotation will cause a slight pull to a swim which can be compensated for in a pool by following the bottom line and resetting every 25 yards.

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