In their book, 80/20 Triathlon, Coach Matt and Coach David identify no fewer than eight factors that keep athletes stuck in the “moderate-intensity rut” of training intensity. Bronwyn Tagg, a 19-year-old triathlete from Milton Keynes, England, can speak to several of these factors from personal experience. Bronwyn was first exposed to the 80/20 system in 2017, under the guidance of her coach at the time, Edward Castro. But she resisted it, thinking (as she puts it), “Why train slow when I want to race fast? My body needs to learn to love the pain!” Predictably, she soon burned out.

Reason #4: Lack of buy-in.

In September 2019, Bronwyn moved north to train at the Leeds Tri Centre in the company of some of the UK’s top elite triathletes. This turned out to be a double-edged sword. Although swimming, biking, and running with the likes of Alistair Brownlee and Georgia Taylor-Brown inspired and motivated Bronwyn, it also seduced her into abandoning the 80/20 principle a second time in the effort to keep up with her older, more experienced teammates.

Reason #6: Ego (a.k.a. the Strava effect)

To her credit, Bronwyn took the lesson to heart. “Your zones are the same as anyone else’s,” she advises, “so accept them and work with the stats rather than comparing them to other people’s numbers.”

When the COVID-19 pandemic struck and her 2020 racing season was cancelled, Bronwyn seized the opportunity to get serious about 80/20 training once and for all. For the past few months, she has strictly enforced a ceiling of 70 percent of maximum heart rate in her easy swims, rides, and runs, and her discipline has paid off, with her run pace at 160 BPM dropping dramatically during this span. Young, gifted, and now fully enlightened about how to train and how not to train, Bronwyn has an exciting triathlon future ahead of her. Follow her journey on her Audacity to Tri blog.