Pace Yourself for Your Best Duathlon Ever

By Jason Digman | April 24, 2012, 5:13 p.m. (ET)

It has long been my view that pacing a duathlon properly is one of endurance sports’ greatest challenges. Between running two separate times, coupled with the high intensity of both the runs and the bike ride, it’s a tall task to nail pacing a duathlon so to maximize your performance. By maximizing performance, I’m speaking of going as fast on the day as was possible given current fitness. With USAT’s Duathlon Nationals coming up, and spring duathlon season starting throughout much of the U.S., it’s a great time to discuss duathlon pacing.

As an endurance athlete, you show up at a race with a fixed amount of fitness to spend, what I like to term your fitness budget. With that budget, your race-day goal is to use it to get the most speed you can. We all know that the faster we go, the more it takes out of us. Critical is the knowledge that the costs of going faster do not scale consistently. It is vastly harder to drop one minute when you’re running a six-minute mile than it does when you’re running a ten-minute mile.
Each athlete will withdraw different amounts from their fitness budget going different paces dependent on their threshold fitness in that sport. Get close to threshold and you’re using a good bit of energy, go over and you’re going to be burning that budget out a good bit faster. Short efforts over threshold have a physical toll that is often far greater than the gain you get in terms of speed. For example, it is far less taxing to run one mile at threshold that it is to run half a mile at a pace that is one minute faster than threshold and a half mile at a pace one minute slower than threshold. You’ve used more energy to go the same speed, which makes no sense. By holding a consistent effort across the whole of the event, you are able to gain the most speed for your efforts.

To execute a race plan that revolves around consistency, it’s quite helpful to know your threshold for running and cycling. When we’re talking about knowing your fitness, it’s key to say that we’re talking about the genuine fitness you bring to the race, not the fitness you could of, would of, or should have had. In particular, I typically base things off the pace an athlete could run for an open 10k and their bike threshold, via power or heart rate. You are not necessarily going to be able to perform at those levels in a duathlon, depending on its distance, but those values are the starting point for your race planning.

Before getting into the specifics of how I setup pacing plans for duathletes, it is important to note that duathlon is a specialized sport. Without practicing the particulars of duathlon with its run-bike-run, you’ll likely have trouble holding the effort you might think possible. As such, the recommendations noted here are dependent on some specific duathlon preparation.

Once a run baseline fitness value is established, you need to determine how much of that fitness you’ll be able to bring to your particular duathlon. I almost always suggest athletes plan to run the same pace for both runs, unless the first run is notably shorter than the second. In that case you would go out a bit faster but that is unusual. As I emphasized earlier, the best pacing strategy is the one that gets the athlete to the second run ready to go as fast as possible. To offer a specific example, let’s say you can and/or have run a 10k in 40 minutes and are racing the upcoming USAT Duathlon National Championship, which has dual 5k runs. Same distance, same pace, right? Well, no.

My typical recommendation is to add the total distances of your duathlon run legs together and then assume you’re racing a standard running distance one step longer, i.e. if the duathlon totals 10k of running, then pace the runs off the idea that you’re racing 10 miles open. 15k of duathlon running equals half marathon pace open. Online pace equivalent charts, such as McMillan Running or Jack Daniels’ VDOT tables work well for establishing these paces.

Such pace charts suggest that for a 40 minute 10k athlete, the pace for racing a 10 mile event will be about 15 seconds per mile slower, around 6:25-6:40. A well-done nationals would have this athlete running 6:40 miles for the first 5k and the second 5k as well. I know this looks conservative and is far different from how many people like to race. Yet, as I always tell my athletes, run the first run at that pace and if you feel great on the second run, go faster. You won’t have lost much time and the energy you saved is still there to use. The reverse is certainly not the case — if you take that first run out too fast, you’ll be spending your fitness budget very quickly and not getting nearly the speed back that you might otherwise. It’s far better to err slightly on the conservative side for that first run. Duathlons hurt anyway, no reason to make the second run more difficult than it needs to be. 

I find that 90 percent of pacing errors in duathlon take place in the first run. The majority of the rest come in the first 10-15 minutes of the bike. Like my suggestions for the run, it’s all about starting at an effort that is sustainable and/or just a tad easier than what you’ll do across the whole of the bike course. To apply this to our Duathlon Nationals example, I would say to start around 85-90 percent of threshold for the first 15 minutes of the 35k ride. Generally, athletes are able to hold 85-92 percent of their open bike fitness in standard-distance duathlons, with well-practiced and trained athletes around 88-92 percent for international distance duathlons (10k-40k-5k) and a bit more for 5k-30k-5k events.

The pacing recommendations above are conservative, particularly when compared to how many athletes typically race duathlons. Through my years of coaching duathletes of all levels, I can say without any doubt that the crowd doesn’t always know best. While these pacing guidelines get the most speed for the athlete, that does not mean they are easy to execute. It’s hard to watch those people run away from you early on in a race, particularly when you’re excited and ready to race, but they don’t give away the medals for the first athlete into T1. By using a realistic accounting of your fitness budget, you can set pacing plan that will take you to your best performances in your upcoming duathlons.

Jason Digman is a USA Triathlon Level I Certified Coach and a Level II coach with USA Cycling. He coaches duathletes of all levels, having worked with beginners, national champions and folks everywhere in between via Dig It Triathlon and Multisport, a coaching company he founded in 2006. Jason was also the assistant coach for the U.S. at the 2008 ITU Duathlon World Championships.

The views expressed in this article are the opinion of the author and not necessarily the practices of USA Triathlon. Before starting any new diet or exercise program, you should check with your physician and/or coach.