Canadians light up whenever The Lion drops a new YouTube video. And after missing him on start lines for much of this season, every glimpse into how his recovery is progressing has captured fans’ attention.

Perhaps that’s because Sanders offers something few elite athletes do: a genuinely transparent, honest, and introspective look at his career. Win or lose, he openly shares not only what happened, but what he learned. And it’s one of the defining characteristics of great athletes – a relentless commitment to continuous learning and the pursuit of becoming not just better, but smarter.

In his latest video, Sanders explored a fascinating concept that extends well beyond his own comeback: the difference between mechanical and metabolic load, and why understanding that distinction could help athletes train more effectively.

Mechanical Versus Metabolic Load

Training load is often discussed as though it’s a single concept. But in reality, there are many different types of load, each designed to drive different physiological adaptations.

For triathletes, load is first distributed across the three disciplines of swimming, cycling, and running (plus complementary training such as strength work). Within each discipline, there is also variability. For instance, a high-intensity interval session places very different demands on the body than a long aerobic endurance session, even though both contribute to overall fitness.

But the way Sanders breaks it down is refreshingly simple and something I hadn’t heard articulated in quite this way before: mechanical load versus metabolic load. 

In a previous interview with Project Podium Head Coach Parker Spencer, he shared a line that has stuck with me: “Metabolism is fitness.” He was referring to the measurable physiological adaptations that underpin endurance performance: our aerobic capacity, lactate profile, fuel utilization, and other characteristics of our energy systems.

Sanders’ latest video builds on a similar idea. He explains that it’s possible to place a very high metabolic load on the body, stimulating those physiological adaptations, while carefully managing mechanical load, the impact and musculoskeletal stress placed on the body. This distinction is particularly relevant in running, where repetitive impact places much greater stress on joints, tendons, bones, and other injury-prone tissues than swimming or cycling.

He also reflects on his own career, acknowledging that until his mid-thirties he was fortunate to possess an exceptional level of durability. He could tolerate his desired training load with relatively little interruption from injury. But if his recent run of injuries has taught him anything, it’s that managing mechanical load has become just as important as maximizing metabolic load.

Considerations for Your Own Training

When considering how this might apply to your own training, Sanders highlights that mechanical load is inherently much lower in the swim and on the bike. With running, he recommends considering treadmill running and/or softer surfaces, and the video shows him using the lever device on the treadmill to further reduce weight-bearing.

Videographer (presumably Talbot Cox) jokes that this looks like cheating or making the session easier, but Sanders quickly points out that the workout was still very hard. Just press the speed or incline button if it’s too easy, he joked. Once again, it highlights how metabolic load can remain high while mechanical load, and therefore impact, is reduced.

Of course, there is a time and a place for full-impact running. But when designing your overall training plan, it’s worth considering what your biggest limiter actually is, and whether your performance could be further optimized through the strategic management of mechanical load.