Metronomic pacing and average heart rate under 170: Alex Yee’s amazing Valencia Marathon in numbers

Olympic triathlon champion Alex Yee produced an incredible marathon display recently in Valencia when he recorded the second-fastest time by a Briton over the distance.

Having clocked 2:11:08 on his 26.2-mile debut in London in April, he knocked four-and-a-half minutes off that time in Valencia with a sensational 2:06:38.

That means that only the great Sir Mo Farah is ahead of him in the British standings.

Fastest at the finish

And COROS have released the data from Alex’s heart rate strap and watch, which underline just how special the performance was as well as how it compares to London.

The key metrics were as follows:

• His pacing was metronomic throughout the first half, only varying outside of his average pace of 3:01/km by 5 seconds for any KM split. 
• This actually continued right the way through to 40km. His biggest drops in pace came during his final push to the line! His final 400m was mind-blowing 64 seconds, which is the same pace as his 5,000m PB! 
• His pacing was a masterclass in energy preservation and his average heart rate remained in the mid 160bpm range for the entire first half, only drifting as the heat rose and distance racked up. Even then it was under 170bpm overall – click here for his Strava file.
• And he not only his maintained stride length and cadence, but actually improved them in the last 10km. The table below also compares them to London.

Cadence and stride length are strong indicators of fatigue resistance and are inherently intertwined. Speed can be expressed as stride length X stride frequency (cadence), so if one of these changes, speed will change as well.

How the training ramped up

While Yee has focussed on running this year, before the real build to LA2028 starts in 2026, he has still been cycling and swimming.

He achieved his biggest running mileage week around four weeks prior to Valencia, topping out at over 170km, with an additional 250km on the bike for good measure.

That totalled a staggering 20 hours across those two disciplines alone for that week as well as strength work and other aspects of his training which is a significant increase compared to his regular running average of 70km during his triathlon preparations.

You can read much more about Alex’s training plan into Valencia on the COROS blog here.