THE SCIENCE BEHIND CURV





THE SCIENCE BEHIND CURV

THE SCIENCE
BEHIND CURV

Women's Cycle Health
Data Project


Grounded in peer-reviewed studies across

reproductive endocrinology, chronobiology, and female physiology.


Grounded in peer-reviewed studies across

reproductive endocrinology, chronobiology, and female physiology.

Building the Data Infrastructure for the Next Era of Women's Cycle Health

Why Women Need a Different Model

Why Women Need a Different Model

For decades, wearables have been built on male-centered biology — assuming your body operates the

same way every day.


Women's bodies don't work like that.


  • Your heart rate, body temperature, HRV, and sleep stages shift every week of your cycle — there is no single "baseline"

  • The same workout, the same sleep schedule, the same diet produce different outcomes depending on your hormonal phase

  • Life phases — pregnancy, postpartum, perimenopause — require entirely different models, not just adjusted thresholds


Your body is not inconsistent. It's dynamic. It follows a pattern.

CURV's Rhythm Intelligence is a female-first model built to decode your biological rhythms and

deliver health insights that adapt to your body.

Your Body Runs on Three Rhythms

Your Body Runs on Three Rhythms

Meet the three biological rhythms —— the multi-layered timing system that drives women's health

The Daily Rhythm (Circadian)

Your 24-hour cycle of cortisol, melatonin, and body temperature. It controls when you feel alert, when you sleep, and how you recover. In women, this rhythm shifts across the month in ways male-based models never

account for.


The Monthly Rhythm (Menstrual)

A 21–35 day hormonal cascade that doesn't just control your period — it reshapes your sleep, metabolism, immune function, mood, and brain chemistry every single month.


The Life Rhythm (Life Phase)

From puberty to postmenopause, your body moves through fundamentally different operating states — each with its own rhythmic signature that changes how the other two layers behave.


These three rhythms interact, overlap, and shape each other. CURV's Rhythm Intelligence™ tracks how they influence your body — understanding what your rhythms affecting yourd your sleep, energy, mood, and health in a whole picture.

How Your Rhythms Shape Your Body-Mind Balance

How Your Rhythms Shape Your Body-Mind Balance

Your rhythm system actively drives what you feel, how you perform, and whether you recover — a new

lens to understand your health as a whole.


Here's how your three rhythms show up across every dimension of your daily life:

Menstrual Cycle & Hormones


The menstrual cycle is not a single event — it is a 21–35 day hormonal cascade that reorganizes

nearly every physiological system. Estradiol, progesterone, LH, and FSH rise and fall in a

coordinated sequence, altering thermoregulation, immune activity, neurotransmitter synthesis, and

metabolic substrate use. Each phase — follicular, ovulatory, luteal, menstrual — creates a distinct

internal environment.


These hormonal shifts produce real, measurable symptoms: breast tenderness, pelvic cramping,

headaches, water retention, acne flares, joint laxity, temperature elevation, and changes in

cervical mucus — all signals of a system in constant transition. What women often dismiss as "random

bad days" are predictable consequences of where they sit in this cascade.


CURV's Rhythm Intelligence maps your position within this hormonal sequence and interprets your

biometrics accordingly — turning isolated symptoms into a coherent physiological narrative.


Sleep & Recovery

Sleep architecture is not static across the cycle. Progesterone elevation in the luteal phase

reduces slow-wave sleep duration, increases nighttime awakenings, and raises core body temperature —

all of which degrade sleep efficiency. Estrogen withdrawal around menstruation disrupts sleep onset

latency. During life phase transitions — perimenopause, postpartum — circadian alignment itself

becomes unstable, and sleep fragmentation can persist for months.


CURV identifies these hormonally-driven sleep changes and distinguishes them from behavioral factors

— giving you an accurate picture of what's driving your sleep quality and where recovery is truly

compromised.



Mood & Stress


Ovarian hormones are neuroactive. Estradiol modulates serotonin and dopamine receptor density;

progesterone metabolites (allopregnanolone) act directly on GABA-A receptors. When these hormones

shift rapidly — particularly in the late luteal phase — the neurochemical environment changes within

days, creating vulnerability windows for mood instability, irritability, anxiety, and heightened

stress reactivity. This is not psychological — it is biochemical.


CURV correlates your physiological stress markers with cycle phase, making the hormonal signal

visible within what otherwise feels random — and helping you distinguish a hard day from a hard

phase.



Energy, Metabolism & Movement


Estradiol promotes glucose uptake, supports mitochondrial efficiency, and enhances exercise

motivation. In the high-estrogen follicular phase, performance capacity, VO2 max utilization, and

metabolic rate are elevated. As progesterone dominates in the luteal phase, the body shifts toward

fat oxidation, insulin sensitivity decreases, and perceived exertion rises for the same workload.

Training without accounting for this means you're either under-recovering or under-performing —

without knowing why.


CURV tracks your energy and activity patterns relative to your cycle phase — showing you when to

push, when to adapt intensity, and when to prioritize recovery.



Appetite, Gut & Nutrition


Estradiol suppresses appetite via hypothalamic signaling. When it declines in the luteal phase, this

restraint is reduced — caloric drive increases by an estimated 100–300 kcal/day, with heightened

preference for carbohydrate and fat-dense foods. Simultaneously, progesterone slows gastrointestinal

motility, contributing to bloating, altered bowel patterns, and changes in nutrient absorption

timing. Micronutrient demands also shift across the cycle — iron loss during menstruation, increased

magnesium utilization in the luteal phase, and fluctuating B6 requirements that support

progesterone metabolism.


CURV contextualizes your appetite, digestive, and nutritional shifts within your hormonal pattern —

reframing them as predictable physiology rather than behavioral failure.



Cognition & Focus


Estradiol enhances prefrontal cortex activity, supporting working memory, verbal fluency, and

executive function. Progesterone can dampen cognitive processing speed and reduce attentional

control. Research documents measurable shifts in attention and memory performance across cycle

phases — including the "brain fog" many women report in the late luteal phase. These are not signs

of decline; they are transient, hormonally-mediated shifts in neural resource allocation.


CURV models your cognitive readiness based on sleep quality, HRV, and cycle phase — helping you

align high-demand tasks with your phases of peak mental clarity.



CURV reads your health through two dimensions — Body and Mind — connected by one underlying engine:

your Rhythm. Every metric is interpreted relative to where you are in your cycle, your day, and your, life phase.

Body — how you sleep, move, digest, and recover.

Mind — how you feel, focus, and handle stress.

Rhythm — the hormonal timing system that explains why both shift.

This is Body-Mind Balance — not a static score, but a dynamic understanding of how your whole system

finds equilibrium. CURV doesn't just show you what's happening — it shows you why, and how to find

your balance.

How CURV Rhythm Intelligent Works:

Sense → Understand → Guide

How CURV Rhythm Intelligent Works:

Sense → Understand → Guide

Sense — Continuous, Whole-Body Tracking

CURV combines 24/7 physiological sensing with a complete female symptom logging system — capturing

both what your body is doing and what you're experiencing.


What CURV measures :

An advanced sensor array built into a single ring — optical PPG, infrared thermometer, and 6-axis

motion sensing — continuously capturing:

  • Sleep quality & recovery

  • Heart rate & HRV

  • Stress & resilience

  • Body temperature & cycle phase

  • Activity & energy expenditure

  • Blood oxygen & respiratory rate


What you log:

  • Period & fertility — flow, clots, color, spotting, discharge, ovulation signs

  • Symptoms — pain, bloating, breast tenderness, skin changes, cravings, digestive shifts

  • Mood & energy — energy level, mood state, mood triggers

  • Daily context — water intake, caffeine, supplements, exercise, stress events



Understand — Your Personal Rhythm Intelligence

Built on female-first data — our models are trained exclusively on women's physiological datasets

and validated peer-reviewed female health research.

CURV's AI doesn't compare you to population averages. It builds your unique baseline — and watches how it

evolves.

Personal baseline modeling:

Your metrics from cycle to cycle are compared against yourself — not a generic 28-day template. CURV

learns your unique cycle length, your typical HRV range in each phase, your temperature shift

pattern, and your individual sleep architecture.


Cross-cycle pattern recognition:

The AI identifies recurring signatures across your rhythm layers — detecting which symptoms cluster

together, which phases are your vulnerability windows, and how your patterns shift over months.

("Your insomnia and bloating always co-occur on cycle days 22–25." "Your HRV drops 3 days before

your period starts.")


Early shift detection:

By learning your personal norms, CURV detects deviations before they become symptoms — flagging when

your rhythm is drifting from its usual pattern, so you can respond early rather than react late.


Powered by adaptive AI:

CURV's rhythm engine combines time-series analysis, cycle-phase segmentation, and multi-signal

correlation — continuously learning from your data. The longer you wear it, the smarter it gets.


Guide — Actionable, Science-Backed Insights

Based on where you are in your rhythms right now, CURV delivers personalized guidance that adapts to

your body's current state:

- Nutrition — micronutrient and macronutrient timing aligned with your metabolic shifts

- Movement — exercise intensity recommendations matched to your hormonal energy arc

- Recovery — when to prioritize rest based on your HRV trend and cycle phase

- Skincare — Routine adapted to hormonal skin changes across your cycle

- Mental load — when to schedule demanding cognitive work vs. lighter tasks


Every recommendation is generated from your personal rhythm model — your data, your patterns, your current phase. It updates daily as your body moves through its rhythms.

Build the future together!

Build the future together!

We're actively collaborating with researchers, clinicians, and domain experts dedicated to advancing

women's health science. If you share this mission, let's build the future of women's health

together. [Join Our Research Program →]