To make "carrying the load" a more consistent practice, the author interviews the founder of GORUCK, an ex-Green Beret who promotes rucking as the ultimate full-body workout. Jason McCarthy defines rucking as walking with a weighted backpack at a decent clip, enough to get the heart rate up.

Rucking has a long history in military training and hunting/gathering, and is still the primary way Special Forces soldiers build endurance and mental toughness. But it's accessible to anyone. Experts recommend working up to carrying 20-50 pounds and going for 30-60 minute ruck walks multiple times per week, either with a weighted pack or weighted vest. Keeping the weight ≤50 pounds minimizes risk of injury while still providing ample physiological challenge.

Section: 1, Chapter: 20

Author: Michael Easter

After pushing through the pain and exhaustion of packing out his caribou, the author feels noticeably stronger and more capable. Where the first few miles utterly taxed him, by the end he finds a semblance of ease in the effort, tapping into new reserves.

He learns that 80% of people who train conventionally in the gym still fold on their first day in true backcountry conditions. Being fit isn't the same as being useful, durable and adaptable. The author realizes that what's missing in modern fitness is the regular inoculation of productive discomfort; intentional challenges that build the capacity to sustain long, grinding, full-body exertion without breaking down.

The author makes a vow to start cross-training his body and mind for the unknown and the uncomfortable. Not through sado-masochistic feats, but through practices that progressively, controllably nudge his thresholds. More long hikes with a pack. More time in the cold. More hauling awkward objects. Discomfort inoculation as a preventive discipline, rather than an emergency crash course.

Section: 1, Chapter: 21

Author: Michael Easter