There’s always a lot of anxiety over races on the cusp of being wetsuit legal and IM 70.3 Muncie is no different. It’s considered a bit of a tricky swim, so most people prefer the security of a wetsuit. I have been on the fence because I really don’t like wearing them, but in the name of sports science, I decided to do a comparison test this morning to see how it affected my time.
This was the setting.
– Lake was smooth
– Water temp estimated to be around 77 degrees
– Air temperature about 69 degrees
– Partly cloudy
– Test distance estimated to be a 350 yard loop (roughly 1/6 of a Half Ironman)
– I warmed up for about 900 yards
– Swimming effort – Moderate
– Total sleep before test, about 3 hours.
The swim skin test was first and I swam the 350 yards in roughly 5:56.
I then changed into my wetsuit and swam the identical loop in 5:31. A twenty five second difference and I felt like it took noticeably less effort.
That’s roughly 2:30 difference over the course of a Half Ironman with, in theory, less exertion. But heart rate and core temperature are other issues that should probably be considered.
One of the reasons I wasn’t sure I’d wear a wetsuit, even if legal, was body core temperature. The last time I wore my wetsuit was Challenge Knoxville where the water and air temp were much cooler but I felt like I was burning up in that swim. We’ve written about this before concerning Ironman Chattanooga, but that proved to be a different animal with the current.
How accurate these test numbers are is debatable, but what was most interesting to me was comparing a wetsuit immediately after swimming without one. Today, the buoyancy was obvious and definitely had an impact on my confidence.
I’m glad I did this test and will be fine with or without a wetsuit in Muncie, but if it’s legal, I will definitely be wearing one.
Here’s another test by someone who did longer distances and compared multiple times.
And for those of you having trouble distinguishing between a tri suit and a wetsuit, active.com has you covered with this insightful piece.