Crushing Iron Triathlon Podcast · Crushing Iron

#885 – Heart Rate, Power, or RPE?

·58 min·5 clips

Robbie explains why he uses power in the morning but switches to heart rate in the afternoon for optimal training.

This episode of the Crushing Iron Triathlon Podcast features hosts Robbie and Mike discussing how triathletes should gauge their training and racing efforts. The hosts, experienced coaches and athletes based in Nashville, explore the practical use of various performance metrics. They examine the three dominant metrics: Rate of Perceived Exertion (RPE), heart rate, and power output. A central argument is that athletes often become overly attached to a single metric, like power or pace, without considering external factors like temperature. The hosts use the example of an athlete using a power target developed in cool weather during a hot, humid race, which could dangerously elevate heart rate. They reference specific early-season races like Ironman Texas and Gulf Coast 70.3 as common scenarios for this mismatch. Robbie shares a personal method of selecting metrics based on time of day and discipline, such as using power on morning bike rides when caffeine and mild dehydration can skew heart rate. He advocates for using heart rate in the afternoon when the body is more settled and hydrated. For swimming, he always relies on feel, noting how pool temperature and depth at facilities like Nashville's Centennial Sportsplex versus a local YMCA drastically change effort for the same pace. One surprising insight is the hosts' speculation about the potential influence of local officials on wetsuit legality decisions at Ironman events, suggesting city-affiliated staff might be incentivized to report lower water temperatures. They emphasize that respiratory rate and breathing comfort are crucial components of RPE, often more telling than a watch. A memorable moment involves Robbie describing a recent bike test where seeing his improved power average mid-test caused him to alter his effort to maintain it, demonstrating how data can unconsciously influence performance. They explain the "heart rate lag" phenomenon, where heart rate peaks during recovery after short, hard intervals, making power a better guide for those efforts. The conversation also covers balancing training intensity, referencing triathlete Christian Blumenfeld's high VO2 max not guaranteeing race victory, and the importance of building a durable "chassis" alongside a powerful engine. The tone is highly conversational and educational, flowing from anecdotal stories to practical coaching advice. The style is relaxed and digressive, beginning with humorous banter about fall weather and wetsuits before settling into the core topic. This episode is ideal for data-driven triathletes or coaches seeking a nuanced discussion on integrating metrics with bodily feel, especially during seasonal transitions. Listeners looking for a highly structured, scripted presentation or a debate with opposing experts might find the casual, meandering style less engaging.

As heard by us

A direct triathlon conversation about training intensity, injury risk, and keeping the work simple.

Crushing Iron settles into familiar triathlon questions about how hard to train and where effort should go, but it keeps returning to practical race prep instead of drifting into abstraction.

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Why you'd press play

Pick this if you want a practical triathlon chat about balancing training load without making it weird.

Read the full recommendation in PlayNext →

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