The 4-Hour Body: Pre-Hab and Injury Prevention
These two chapters cover very different topics. One is about saving money on medical tests by flying to Nicaragua. The other might be the most important chapter in the whole book - how to not get injured in the first place. Let’s go.
Pay for Your Vacation with a Hospital Visit
Tim is lying in an MRI machine in Managua, Nicaragua. It’s late at night. His MRI technician Edwin loves Celine Dion and won’t stop talking about it.
Earlier that trip, Tim had rented a hilltop villa with a pool, chartered a boat for private surf spots, hired a chef to cook the fish they caught. Standard Tim Ferriss vacation. Total cost for two and a half weeks including food: about $2,400.
Here’s the trick. He walked into the hospital emergency room on a Sunday night at 10:30 PM with no appointment. Asked for MRIs of every joint that ever hurt from sports. The list price was $600 per scan. He negotiated a volume discount - seven MRIs for $400 each, paid in cash. While waiting for the technician to arrive (they sent a car to pick him up from home), the doctors shared fruit with Tim and helped him pick out 25 blood and urine tests.
Results came back in three hours. In San Francisco, the same blood work takes seven to ten days.
The math works out like this. Seven MRIs at $400 instead of $750 each saved $2,450. Blood and urine testing saved another $640. Total savings: $3,090. That’s $687 more than the entire vacation cost.
He basically got paid to go surfing in Nicaragua.
The bigger point is practical. Those MRIs later saved him weeks of wrong diagnoses back in the US. American doctors get an average of 11 minutes per patient. They make guesses. They don’t order imaging unless forced to because insurance companies audit them for it. Tim could now pull an MRI out of his bag and say “let’s make sure.”
If you need dental work, blood panels, or any kind of imaging - consider combining it with a vacation somewhere the medical costs are 50-70% less. The trip might pay for itself.
Pre-Hab: The Chapter That Could Save Your Body
Now the important part. Tim calls this the longest and most difficult chapter in the book. He also says for many readers it will be the most important one.
The idea is simple. If you’re doing any kind of strength or speed training from this book (or anywhere else), you need to injury-proof your body first. Getting in an F-1 racecar without checking the tires is stupid. So is chasing personal records when your body has hidden imbalances.
Meet Gray Cook
Gray Cook is maybe the world’s top injury-prevention specialist. His client list is insane. In 2007, both teams in the Super Bowl used him. The Pentagon hires him for Special Forces operators. He fixed Michelle Wie - the golf prodigy who at one point couldn’t do a single push-up despite being a Nike-sponsored professional athlete.
Michelle could still crush a golf ball 320 yards even when injured. But she was inconsistent. Power was there. Stability was not. After working with Gray, she could still drive 320 yards - but now she could do it 300 times a day without breaking down.
Gray’s core insight: the biggest cause of injury is not weakness or tightness. It’s imbalance. Left-right differences. Your core might work fine when your hips are still. But the moment your hips start moving - running, lifting, even carrying luggage - those imbalances show up and you get hurt.
The Functional Movement Screen
Gray created the Functional Movement Screen (FMS) - seven movement tests scored on a three-point scale, done by a certified professional. For self-testing, you can simplify it to five pass/fail movements:
- Deep squat
- Hurdle step
- In-line lunge
- Active straight leg raise
- Seated rotation
You’re looking for two things: left-right asymmetry and wobbling. Even if you can bench 600 pounds, that doesn’t mean your shoulder won’t pop out during a game. Strength should never exceed stability. As Gray puts it, trying to fix stabilizers in isolation is “like pissing in the ocean.”
Does it work? The Atlanta Falcons had seven season-ending injuries in 2007. Their new performance director made the FMS mandatory. In 2008, one minor surgery all season. The Indianapolis Colts have been the smallest NFL team for nine years straight. Also the fewest injuries and the most wins. Their strength coach has used the FMS the entire time.
The Critical Four Exercises
Tim asked Gray to pick the 2-4 exercises that fix the most common problems. Gun to your head, what do you pick? Gray answered without hesitation:
1. Chop and Lift (C&L). You kneel in a half-kneeling position on a cable machine. Chopping is pulling the cable diagonally down across your body. Lifting is the reverse - pulling up diagonally. You test all four quadrants (chop left, chop right, lift left, lift right) to find your weakest one.
Tim’s first test showed a massive imbalance. He could do 15 reps chopping to the right but only 7.5 to the left. Four workouts later, he was doing 45 pounds on both sides. His back pain from sitting and writing disappeared.
2. Turkish Get-Up (TGU). If Gray had to pick just one exercise from all four, this is it. You lie on the ground holding a weight overhead with one arm, then stand all the way up without lowering it - through nine distinct movements. The Colts’ head strength coach says: “I start with the TGU. I finish with the TGU. I check progress with the TGU.”
Gray calls it the “Save Document” function. The chop and lift works the upper body while the lower body stays still. The deadlift works the lower body while the upper stays still. The TGU pieces them together. Without it, your gains don’t integrate.
Starting weights for men: 8-12 kg beginner, 12-16 kg intermediate, 16-24 kg advanced. Women: 4-6, 6-8, 8-12 kg respectively.
3. Two-Arm Single-Leg Deadlift (2SDL). A regular deadlift but on one leg, holding a dumbbell in each hand. This is the learning version.
4. Cross-Body One-Arm Single-Leg Deadlift (1SDL). Same thing but with one weight in the opposite hand from the standing leg. This creates rotational force that your core has to resist. Key rule from Gray: set the weight down between every rep. His deadlift injury rate is zero because of this.
The Schedule
Here’s the condensed version of Tim’s program:
Week 1, Tuesday: Practice all four movements with light or no weight. 30-45 minutes. This is not a workout - it’s learning the patterns.
Week 1, Thursday and Saturday: Test to find your weak side. Do it twice to confirm. Don’t plan a whole program around a fluke.
Weeks 2-6, Monday and Friday: Fix the imbalances. Use a 2:5 ratio - two sets for your strong side, five sets for your weak side. Keep reps between 3-5. One minute rest between sets. 30-45 minutes per session.
Week 7 and beyond (optional): Retest every 4-6 weeks. Once imbalances are corrected (less than 10% difference), switch to equal sets per side.
The Bottom Line
Thirty to forty-five minutes, twice a week. Four exercises. That’s it.
Tim puts it bluntly: this takes less time than 6-24 months of recovery after a major injury.
The whole chapter is dense with technical details about hand placement, breathing patterns, and foot positioning. But the core message is dead simple. Find your imbalances before they find you. Fix them with a small, consistent investment of time. Then go train hard with confidence.
Focus on pre-hab so you never have to do rehab.
Previous: Reversing Permanent Injuries
Next: Hacking the NFL Combine
This is part of my 4-Hour Body retelling series. New posts every Saturday.