I experimented with probably my most unpleasant, yet effective diet ever this week: The 4-Day Diet.

Inspired by a recently published randomized trial, I decided to test out the diet’s rather extreme prescription of all-day walking and near starvation.

Like the participants who lost an average of 11 pounds in a mere 4 days, I also rapidly lost fat: I dropped 1.3 percent body fat, which is about twice as fast as my previous diet (0.7 percent in a week). Even more extraordinary, like those in the research study, I keep shedding my waistline—two days after returning to my normal diet, I’ve lost another 0.5 percent in 2 days.

But, in addition to constant hunger, the 4-Day Diet had other unexpected side effects, like peeing blood, and blisters—in NC-17 rated places. Here’s how I managed through it, without taking a minute off work.

What’s the study this is based on?

A research team in Spain tracked 15 obese participants over a year, after they subjected themselves to a diet of about 360 calories a day while walking for eight hours. Imagine going from three big American-sized meals a day to a small salad. “We thought they would overeat and regain the weight lost,” Dr. Calbet told The New York Times , but after a month, many had lost even more weight.

Starvation diets are highly controversial, both because people need food to live and because sometimes the body can power-down its metabolism in response. Indeed, my body’s Borg-like adaptation to dieting is why I employ a strategy of systematic binging to ramp up my metabolism after my fat-loss plateaus (so-called “Ketogenic cycling”).

How did you modify it?

I’ve subjected myself to some weird diets in the name of journalism, but I have a rule that I always try to eat real food and get plenty of high-intensity exercise. Though the participants were allowed a protein shake and a low-calorie Gatorade-type substance, I avoid experiments with anything that doesn’t involve at least some type of nutrition. Also, I have to work and can’t spend four days prancing around the Scandinavian countryside.

I ate a total of 220 calories (or 3.2 kcal/pound): 100 grams of local-caught wild Alaskan Salmon, 10 blueberries, a teaspoon of honey comb from the California Delta, and a half-pound of leafy greens (rotating spinach, kale, and mesclun mix on different days)

I walked: ~15 miles per day, half on a walking treadmill desk and the other half between meetings around San Francisco. Thank goodness for global warming. It was much easier to convince my meeting partners to trek San Francisco’s brutal hills under the crystal-clear skies. I also did one exercise a day.

I’m interested, what are the tricks you used?

A few things helped:

1. Green tea. The lightly caffeinated beverage tapered my appetite while ensuring I had some nutrition.

2. Lube. Chaffing is a novel thing to experience at the office. Repurposing lubricants offers a pleasant reprieve, and oddly necessary, reprieve from burning in places I will not describe without an age-verification question. At the end of the day, I rubbed blisters down with raw aloe leaf and then sealed with some good ol’ Vaseline.

3. Rumble roller. Even with my normal running shoes (Reebok, Crossfit, Nano), my knees still got achy after about four hours. Twice a day, I rolled out my legs on my spikey foam friend, the rumble roller. If you’re new to myofascial release, my go-to mobility guru is Kelly Starrett, who has a ton of videos. Warning: this hurts…a lot, but it did release my knee pain.

For productivity’s sake, I rolled out while on phone calls…and hoped that my colleagues chalked up the squeals of pain to a scratchy phone signal.

4. Upper-body workouts. The study had participants do a light “arm crank” exercise. However, I wanted to keep my normal muscle building routine without crushing my already exhausted legs. So, for 30 minutes a day, I’d do P90x3’s at-home boxing workout or ab routine. To give myself a little mental break, I watched the workout videos side-by-side with Star Wars: The Clone Wars on Netflix.

How unpleasant is it, really?

It’s not that bad, really. Most of the men “were surprised that it was easier than they thought it would be,” José Calbet told The New York Times . While I was hungry, it wasn’t any worse than I feel on a normal diet. I never experienced severe or even moderate hunger pangs.

Would you do this again?

Yes, I would. But, I’m not sure how often. After discovering blood in my urine on Day 2 and the pain from my increasingly weak knees, I don’t know how long this diet is sustainable for. While it’s not unusual for long-distance runners to experience urine Hematuria it did freak me out a bit.

Calbet cautions: “People should not try to do this on their own. I strongly advise anyone trying to do this type of intervention to do it under medical control.”

Perhaps, for the future, I’ll try two days on, two days off, or some modification. I love the efficacy, but there has to be a less extreme way.