STUDIES
Scientific Research Shows How
28's Cycle-Based Wellness
Transforms Women's Health
Groundbreaking research reveals the benefits of syncing exercise and nutrition with your cycle

New Research Confirms: Cycle-BasedWellness Boosts Physical and Mental Well-BeingNew Research Confirms:Cycle-Based Wellness Boosts Physical and Mental Well-BeingNew Research Confirms: Cycle-Based Wellness Boosts Physical and Mental Well-Being
By Melissa M. Brillhart, Jeffrey Gassen, Lisa Lin, Gabriel Hugoboom, Brittany Hugoboom, and Sarah Hill
At 28 Wellness, we've always believed in the power of cycle-based wellness —and now, science backs it up. A new study (currently available on Open Science), led by Dr. Sarah Hill, finds that users of 28's cycle-based approach to nutrition and exercise report scoring better on many health and wellness measures than non-users.
The study examined the impact of 28's cycle-based approach to fitness and nutrition, comparing women who follow 28's Cycle-Based Wellness routine to those who don't. The results are compelling: cycle-based wellness significantly improves mental and physical health.
The Results:
1. Happier Mind, Healthier Body: Women who followed 28's Cycle Based Wellness reported higher happiness levels, lower stress, and reduced anxiety and depression compared to those who followed a standard fitness routine.
2. Stronger Body Image & Fitness: Participants who followed 28's Cycle Based Wellness felt more confident in their bodies, more attractive, and overall healthier and fitter.
3. Better Cycle Health: Women who followed 28's Cycle Based Wellness routine experienced more regular menstrual cycles, increased energy levels, fewer food cravings, and better control over eating habits.
4. Reduced Reliance on Doctors: Those following 28's Cycle Based Wellness for at least three months reported a lower need to consult a doctor for menstrual-related symptoms and a better understanding of when medical care is truly necessary.
5. Longer Practice, Greater Benefits: A follow-up study found that women who practiced 28's Cycle Based Wellness for six months or more saw even greater improvements in mental clarity, physical well-being, and hormonal balance.
These findings reinforce what our 28 community has shared the past two years: tuning into your cycle daily is a game-changer, and the 28 app is the first and only scientifically validated cycle-based wellness method.
Other Important Things That We Learned From This Study?
Since they have started using 28, more than:
• 95% of women said that they have felt healthier
• 93% of women said that they have become happier with their body look and feel
• 91% of women said that they have experienced less anxiety
• 90% of women said that they have felt more energetic
• 90% of women said that their cycles have become more regular
• 86% of women said that they have gotten less period pain
• 86% of women said that they have experienced less PMS
• 83% of women said that they have gotten less long/heavy periods
"Although people have been talking for years about the idea of tailoring nutrition and exercise to the unique needs of the cycle, no one has approached it in such a scientifically-grounded way," says Dr. Sarah E. Hill, 28's lead science advisor. "And now that the data are coming in that demonstrate that it’s improving women’s lives, I think that we can feel confident that 28's recommendations are working for women."
The Anatomy of Cycle-Based Wellness
28's Cycle-Based Wellness method is built on four key components: Body Literacy, Feminine Fitness, Hormone-Focused Nutrition, and Lifestyle Guidance.
• Body Literacy: Understanding what's happening in your body at any given time is the foundation of Cycle-Based Wellness™. 28 breaks down the science behind hormonal fluctuations, their impact on the body and brain, and how women can track and interpret these changes to optimize well-being. This includes symptom documentation, cycle phase identification, and insights into rising and falling hormones.
• Feminine Fitness: Traditional fitness programs are built around male physiology and a 24-hour hormone cycle, failing to account for the unique needs of women, whose hormones fluctuate over a 28-day cycle. 28's fitness method—designed by certified celebrity trainers from the Gray Institute—prioritizes low-impact, stability-based movements that optimize hormonal balance by keeping cortisol levels low and adjusting intensity based on the body's needs in each phase.
• Hormone-Focused Nutrition: Developed by certified functional nutritionists, 28's nutrition philosophy shifts away from restrictive dieting and instead emphasizes nutrient-dense, unprocessed foods that deliver the key vitamins, minerals, and macronutrients needed to support hormonal health at every stage of the cycle.
• Lifestyle Guidance: Studies show that women's preferences, energy levels, and cognitive patterns fluctuate throughout the cycle. 28 provides evidence-based insights and recommendations that align with these hormonal shifts to help women work with their bodies rather than against them.
The Technology Behind 28
To make Cycle-Based Wellness truly personalized, 28 developed an advanced technology platform to deliver real-time, tailored recommendations. At the core of this system is a patent-pending algorithm—the most sophisticated content recommendation engine of its kind—combined with a highly accurate phase-specific menstrual cycle tracker. This proprietary technology ensures that every user's experience is dynamically adjusted in real time to meet their unique hormonal needs.
Want to dive deeper into the research? Read the full study:
Preprint: https://osf.io/preprints/psyarxiv/39rwn_v1
Pre-registration for the project: https://osf.io/zutvp/
This article was reviewed by Dr. Sarah E. Hill
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