Ultramarathon vs. Ironman triathlon

Which one is harder?

People always ask me if I think Ironman races or ultramarathons are harder. Here are my thoughts on the two.

Please note, this is based on one 70.3 Ironman race, one 140.6 Ironman race, one 50-mile ultramarathon, and one 100-mile ultramarathon. The things I mention might not be true for all races, as they might be different depending on the organizer, location, etc.

Training

Triathlon training is easier on your body. Because you train in three different disciplines, you don’t spend too much time doing just one thing. Swimming and biking don’t have the same high impact on your body as running does, and the majority of the “endurance” is done on the bike. So I would say triathlon training is not as heavy on your body as ultramarathon training.

Triathlon training is absolutely more technical. The technique is super important in the swim, and somewhat on the bike(remember, an inexperienced amateur writing this). The technical training I did for the ultramarathons was running on trails, and walking & running up and down hills.

Gear

In triathlon, you need a lot of gear. Even just the must-haves. Then there are the nice-to-haves, like a bike indoor trainer, and all the swimming tools to work on the technique. Those things quickly add up and get expensive.

For an ultramarathon, you basically just need shoes and a running vest to carry your nutrition and other stuff. Trekking poles are a nice-to-have in some races.

These are obviously slightly simplified, but you get the point. Triathlon is more expensive than ultramarathon.

Races

There has been a lot of talk about Ironman races lately, and I guess they are a bit “flashier” than other triathlon races. But because I’ve only done Ironman races, those are the ones I can have an opinion about.

Ironman races are like a big party. You get an Ironman-branded backpack when you get your race stuff. The “design” of everything(banners, colors, stands, etc.) around the event area is visually pleasing. There’s music and speakers. A lot of aid stations with a variety of nutrition options. A lot of people cheering. These things stand out more in Ironman races because usually, they try to concentrate as much of the course to as small of an area as possible. The swim start and finish, the run finish, the transition areas, and the main event area are as close to each other as possible. And usually, the run consists of 2–4 loops around the course. So a lot of the race is done in a quite small area, which makes it feel like more of a party because you can hear the music most of the time, and there are a lot of spectators cheering you on. When you finish, you get a big nice medal.

In ultramarathon races, you fill up your running vest and take off. The races are pretty much self-supported. In the 100-mile race I did, there were 7 aid stations and we had two drop bags(e.g. for topping up our own nutrition and changing clothes). You can be running for hours without seeing anyone. The contrast to Ironman races is quite big.

So which one is harder?

Ultramarathons, definitely.

Time-wise, both for me and looking at the professionals — I would say a 140.6 Ironman race equals a 50-mile trail ultramarathon. But the ultramarathon is still harder in the sense that you’re just doing the one discipline — so more impact on the body.