Sisu Endurance Lab

The Weight of Being Weightless: Why Endurance Athletes Get Obsessed, and Why It Never Pays Off There’s a strange seduction that floats around endurance sports, a whispered promise that just a little lighter will make you faster, smoother, more efficient, and perhaps spiritually enlightened (?) in the process. Most of us who’ve spent years in triathlon, distance running, or cycling have brushed up against it. I had a chapter of my life, stretching across a few years, where the

At some point, every serious athlete crosses a line: the moment when the sport stops being something you do and quietly becomes who you are. You stop saying I run and start saying I’m a runner. It’s a subtle shift, but it changes everything. That identity can be powerful fuel. It keeps you accountable when motivation fades, and it provides a sense of belonging in a world that doesn’t always understand why you’re up at 5:00 a.m. chasing watts or pace or heart rate zones. But w

ELITE WINTER BASE WEEK (81 MILES) This is my personal week of running from the winter of 2022-2023, not including my swim (20km) and bike (7 hours) training. For those interested. MON – AM: 8 miles easy / PM: 4 miles easy Mobility + band activation (5–8 min) TUE – 10 miles easy + 6 x 10-sec hill sprints Strength Session (30 min): split squats, single-leg RDLs, calf raises WED – 12 miles aerobic + light mobility/band work THU – Light Tempo Session (11 miles total)

Runners love to talk about strength. Quads of steel, core stability, glute activation, the language of performance often sounds like a weight room. But the best runners in the world aren’t just strong. They’re elastic. Running isn’t a display of muscular force, it’s a symphony of stored energy. Every stride is a cycle of tension and release, a conversation between gravity and the body’s connective web. When your foot hits the ground, your tendons, fascia, and ligaments stretc

If you talk to world-class endurance athletes, especially those coming out of Scandinavia or the Alps, you’ll notice a pattern: a lot of them Nordic ski. Not casually. They grew up logging serious hours on skis before ever specializing in running, cycling, or triathlon. That’s not a coincidence. Even American elites like Ben True, a 13:02 5K guy and one of the most aerobically durable runners in U.S. history, spent his winters Nordic skiing. He was a national-level skier befo

Endurance athletes push the limits of human physiology, relying on efficient energy production to sustain performance over prolonged...

Breakfast Oatmeal with Protein and Peanut Butter 2 cups rolled oats (600 calories, 108g carbs, 16g protein) 1 scoop whey protein powder...

Endurance training induces a complex interplay of hormonal responses that facilitate physiological adaptations, enhancing performance and...

In endurance training, the concept of "threshold" is key. We’ve all heard about lactate threshold, the point where lactate builds up...

The Norwegian Lactate Model: Unlocking Elite Endurance Performance Endurance athletes, from marathon runners to cross-country skiers, are...