Ed. Note—Perfectly executing a 70.3 run split is difficult. You don't fall into the endurance-only intensity of Ironman running, but you have to respect the distance, too. Preparing for this "moderate-hard" level of racing can be difficult, so we turn to Sam Appleton, one of the Wattie Ink. Professionals, for advice. Sam and his coach, Matt Dixon of Purple Patch Fitness, use this workout regularly in Sam's buildup to 70.3 races.
The key to running well in a 70.3 is being able to hold a consistent pace over the 13.1 miles after hammering your legs on the bike. Effective half-marathon running doesn't require a crazy-fast pace per mile, and sometimes even doing 1km or 1mile reps at 70.3 pace in training can seem very manageable. One of my favorite running session is more focused on conditioning the legs to be able to sustain that threshold pace over the course of the half marathon. The session is fairly simple, but for me it is effective in getting my run to a very competitive level:
15min easy warm to find your legs
2 x 20min @ threshold pace (~70.3 pace)
10min easy running in between each round
I would often do this run on a looped, undulating gravel road. It’s critical to not overcook the start of the run efforts as you won’t have enough juice to finish strong. This is one of my tougher run sessions that I would do, and I used this run every week for about 4-6 weeks in my lead up to 70.3 worlds last year. Its great for training the body to find rhythm, and to sustain that uncomfortable pace for extended periods of time. Once completed, this is a great session to have in your back pocket and it always gave me great confidence in my running ability. As my fitness progressed leading into some of my bigger races, I would extend the duration out to 25min and even 30min for bigger weeks.
The key here is to dial in the 70.3 pace, but you should also be able to maintain the pace over the course of the session. If you're blowing up in the back half of the session, try ratcheting the pace back a notch to begin with. It is always better to start off conservative and finish the session strong, rather than risk exploding because you were overzealous at the beginning!