Healthy Living

The 75 Hard Challenge Was Made for Men– “Operation 66” Was Made for Women

"It's designed to change your life."
written by KATHERINE CHANG
operation 66"
operation 66
Graphics by: Caitlin Schneider
Graphics by: Caitlin Schneider

I don’t half-ass anything. I either go all-in or don’t bother (sometimes to a fault): I rival Monica Geller’s obsession with cleaning, and I’ve been known to try every workout trend under the sun—from CrossFit and mud runs to pole dancing and virtual reality fitness—when (as we know) a hot girl walk and some basic weight lifting would do just fine. While my go-big-or-go-home MO had me intrigued by the 75 Hard Challenge, the wellness journalist in me was sounding the alarms and telling me to heed the warning signs that it’s too extreme. So when I got word of Operation 66, a challenge created by a woman for women (but also everybody) to help build life-long healthy habits, it was an immediate green flag for me.

“I felt like I wanted a big change in my life; I wanted to become the person I had always envisioned,” explained the creator of the wellness challenge, Angelina Nicolle. “I needed a challenge that would help me do this, and 75 Hard never really felt like it fit in with my lifestyle. When I heard that it takes 66 days for a habit to become automatic, I decided to challenge myself for 66 days and created the habits that I felt would help me reach my full potential.” Sold yet? Keep reading for the lowdown on the Operation 66 Challenge, including what experts have to say about it and how to give it a shot.

What is Operation 66?

Operation 66 is a 66-day wellness challenge created to help establish lasting healthy habits. To complete the challenge, Nicolle laid out the six simple “rules” or habits to follow for 66 days:

  1. Drink 16 ounces of water first thing in the morning
  2. Avoid social media/screen time for the first and last hour of your day
  3. Do 45-60 minutes of movement (it can be any kind of movement you enjoy)
  4. Dedicate 30-60 minutes toward a personal goal or hobby of yours (something outside of school or your job)
  5. Stretch for 10 minutes
  6. Adopt a 90/10 diet where 90 percent of your diet is made up of whole, unprocessed ingredients, and the other 10 percent is indulging in whatever you want (including alcohol)

“Studies have shown that it takes about 66 days for a habit to become automatic, so the goal is that after the challenge is over, these six habits will be ingrained into your routine,” Nicolle said. But Operation 66 is not just a challenge; it’s not meant to be something you do once and never do again. Rather, it’s an impetus to make permanent positive changes to your life, long after the 66 days are over. As Nicolle emphasized in a TikTok video, “It’s designed to change your life.”

What Sets It Apart From Other Wellness Challenges?

Unlike other wellness challenges like 75 Hard, Operation 66 is more realistic, individualized, and intended to continue after the challenge is finished, making it a sustainable regimen instead of a temporary fix. With 75 Hard, if you slip up on any one of the five rules, you have to start over from day one. But if you skip a day or don’t follow through on one or more of the Operation 66 habits, Nicolle said you just pick up where you left off the next day (“Sometimes, life just happens,” she pointed out). Plus, you can easily tailor the routine to fit into your lifestyle. “The movement can look like whatever exercise you enjoy; your diet can be whatever suits you best; you can choose to focus on any goal or hobby of your choosing,” she said.

Michael Betts, a personal trainer and director at TRAINFITNESS, called attention to the length of time the Operation 66 Challenge involves: “66 days is longer than the usual 30-day challenges, long enough to form habits that stick, not quick fixes. This extra time helps you form deeper habits and make bigger life changes.”

What Experts Say

Pros

“Operation 66 is a well-suited challenge promoting long-term habit-building and aiming for steady, realistic transformation rather than a drastic short-term overhaul,” said Dr. Zulia Frost, MD, a renowned clinician and researcher. “This program is a holistic approach supporting mental, emotional, and physical health as part of a comprehensive wellness routine, including physical activity, nutrition, stress management, and social engagement. It promotes consistency, a key to long-term success. By integrating these gentle practices into daily life, Operation 66 offers an accessible path to achieving a healthier lifestyle with minimal resistance.”

Betts agreed that the guidelines of Operation 66 build sustainable habits, especially compared to standard wellness trends that aren’t approachable for everyone and can’t be modified: “You set your own goals and choose tasks that match your personal needs and aspirations, so you’ll be more engaged and committed.”

Cons

The Operation 66 Challenge is a longer time commitment; Betts said 66 days can be a big ask if you’re already crunched for time or struggle with consistency. Dr. Frost echoed the same potential disadvantage, saying there are no immediate results with Operation 66, as progress may be slower compared to more intense programs. “Since it’s self-directed, results will vary depending on individual effort and circumstances,” Betts stated. “Staying motivated without external support might be tough for some.” Then there’s the potential to feel overwhelmed by trying to do all six steps at once, and if progress is slow, you might burn out, get frustrated, or quit altogether.

How to Try It

Customize the challenge to work for you

Take advantage of the flexibility of Operation 66 by personalizing it based on your needs and what you want to achieve for your well-being. For Nicolle, a 90/10 diet looks like a high-protein vegetarian diet with occasional indulgences (as she said in a video). Case in point: Nicolle enjoying a beer and sandwich roll at a baseball game. Perhaps your take on the 90/10 way of eating means more animal-based products and cutting out alcohol completely in favor of satisfying your sweet tooth. Nicolle’s choice of workouts includes hot Pilates, running, and lifting weights, but that doesn’t make cozy cardio or Pickleball any less beneficial if that’s what gets your endorphins going.

Use habit or wellness stacking

Whether you call it habit or wellness stacking, setting aside time every day to carry out multiple healthy habits simultaneously (in this case, the six practices outlined earlier) takes the pressure of time-consuming self-care out of the equation. “I like to combine my habits so that it becomes more manageable,” Nicolle expressed. Maybe while drinking your 16 ounces of water in the morning, you also use that time to work on your latest hobby (candle-making, anyone?). Or maybe you cue a podcast episode on how to buy your first home as you go on an hour-long walk.

Record your progress

According to research published by the American Psychological Association, the more often you monitor your progress, the greater the likelihood you’ll succeed. Nicolle keeps a journal to document how she’s feeling each day and write about her progress (she also created downloadable worksheets to take the guesswork out of tracking each Operation 66 habit daily). By maintaining a log of your own Operation 66, you hold yourself accountable for completing the six habits every day (but, again, it’s OK if you miss a couple). Plus, it makes it easier to identify what’s working and what could use tweaking or improvement. Consider tracking your progression with a friend who can serve as an accountability buddy. And don’t forget to celebrate your wins along the way, too—they will keep the motivation coming the most.

Experts Consulted

DR. ZULIA FROST, MD

Dr. Zulia Frost is a doctor of general medicine, paediatrics, and Traditional Chinese Medicine (TCM) and acupuncture. She is also the co-founder and clinical director of Recharge Health.

MICHAEL BETTS

Michael Betts is a personal trainer and director of TRAINFITNESS, with over 30 years experience in exercise programming, management, and education.