I’m still processing all of the learnings from Menopause Coachella, aka the Livelong Women’s Health Summit in San Francisco a few weeks ago. The lineup was the who’s who of longevity researchers, including some of my personal heroes like Dr. Sara Gottfried (née Szal, which is her maiden name and far chicer and more fitting), Dr. Stacy Sims (whose famous line “Women are not small men.” changed my life) and many more, each of whom deserve (at least) their own blog.
It’s hard to keep it focused when I try to write about the Summit because there was just so much content packed in. But I will attempt to keep the focus here and get to one of the key messages: women are focusing on the wrong things like: How much can you squat? How much do you weigh? What’s your BMI? Step count?
The doctors asked the room a question that landed differently than expected: what’s your grip strength? Not your weight. Not your dress size. Your grip strength.
It is a deceptively small question with a long shadow. Grip strength turns out to be one of the cleanest predictors we have of how a body is aging beneath the skin, and by extension, how it is aging on the surface. Researchers tracking grip strength against DNA methylation patterns (the molecular clock that tells us our actual biological age, distinct from the candles on the cake) found that lower grip strength tracks tightly with accelerated biological aging in both middle-aged and older adults [1].
That single data point reframes a lot of what we have internalized about beauty.
The scale measures gravity acting on a body. The mirror flatters or punishes depending on light. Neither tells you what is happening at the level of mitochondria, vascular endothelium, dermal extracellular matrix, or sebaceous gland regulation, which is where beauty is actually decided.
What follows is a different starter set. Six metrics with real predictive power, what each one is signaling beneath the surface, and how the dysfunction shows up on your face.
1. Grip strength
What it actually measures: Total-body muscle quality, neuromuscular integrity, and a surprisingly accurate estimate of biological age. The hand dynamometer is one of the cheapest, most validated tools in clinical medicine.
Why it predicts aging: A 2021 University of Michigan study in Geroscience found normalized grip strength was inversely associated with DNA methylation age acceleration across three different epigenetic clocks [1].
Translation: weaker grip, faster cellular aging. Independent work in the Newcastle 85+ Study tied weak grip to elevated inflammatory biomarkers including IL-6 and TNF-alpha [2], the same inflammatory mediators that drive collagen breakdown and skin thinning.
How it shows up on your face: Chronic low-grade inflammation (the kind that tracks with low grip strength) accelerates the same pathways that produce skin thinning, slow wound healing, and the loss of dermal density that reads visually as a less defined jawline and softer cheek architecture. The “ozempic face” concern about hollowing is, mechanistically, a sarcopenia-of-the-face conversation. You cannot have well-supported skin sitting on top of a body that is quietly losing muscle.
The number to know: Peak handgrip strength for women lands around 31 kg (68 lbs) in the 26 to 42 age window, according to pooled data from twelve British longitudinal studies [3]. Anything more than 2.5 standard deviations below your age-matched peak is clinically considered weak. Tested in a few seconds with a $30 dynamometer.
The training intervention: Carries (farmer carries, suitcase carries), deadlift holds, dead hangs, thick-grip work. Grip is trainable at any age.
Warning * humble brag incoming * I got my grip strength tested at the Livelong Summit and I am in the “Peak Vitality” range at 86.5 lbs/85.5 (Canyon Ranch provided this info).
2. Waist circumference
What it actually measures: Visceral adipose tissue. The metabolically active fat that wraps your liver and pancreas, not the soft subcutaneous tissue that pads your hips.
Why it predicts aging: The International Atherosclerosis Society and the International Chair on Cardiometabolic Risk issued a consensus statement arguing that BMI alone is insufficient and that waist circumference should be treated as a vital sign, given its strong independent association with all-cause and cardiovascular mortality [4]. Visceral fat is not inert. It produces inflammatory cytokines, dysregulates insulin signaling, and produces precursors to angiotensin (raising blood pressure) [5]. It is its own endocrine organ, and not a polite one.
How it shows up on your face: Visceral adiposity drives systemic inflammation, which compromises microcirculation in the dermis. Skin gets duller. Repair slows. Healing from minor irritation takes longer. There is also a direct hormonal route: visceral fat increases aromatase activity, shifting estrogen-to-androgen ratios in ways that can drive adult acne, particularly along the jawline and chin in women.
The number to know: Cleveland Clinic and the broader cardiometabolic literature use 35 inches (89 cm) as the threshold above which women face elevated risk [5]. Measure just above the hip bones, exhale normally, do not suck in.
Why it is more honest than the scale: Two women at the same weight can have radically different visceral fat profiles. The scale flattens that distinction. Your waist does not.
The intervention: Visceral fat is metabolically active, which makes it the most responsive fat depot to lifestyle change. Strength training and zone 2 cardio both reduce it, but the largest effect comes from improving insulin sensitivity, since hyperinsulinemia is what tells the body to store fat viscerally in the first place. Practical levers: protein at every meal (30+ grams), removing liquid sugar (juices, sweetened drinks, alcohol), prioritizing sleep (one bad night measurably worsens insulin sensitivity the next day), and resistance training. Spot-reduction does not exist. Crunches build the abdominal wall underneath the fat, they do not remove it. If you are doing “all the things” and you want extra support riding the blood sugar rollercoaster, dealing with cravings, and rapid skin aging, we created something that works at evidence-based doses: The Golden Sequence
3. VO2 max
What it actually measures: The maximum volume of oxygen your body can use during intense exertion. Functionally, it tells you how well your cardiovascular, respiratory, and mitochondrial systems are talking to each other.
Why it predicts aging: A 2018 review in Frontiers in Bioscience-Landmark called VO2 max the strongest single predictor of life expectancy among standard fitness metrics [6]. Cardiorespiratory fitness drops roughly 10 percent per decade after age 30, but the trajectory is highly modifiable. The American Heart Association has formally recommended that VO2 max be incorporated into routine clinical assessment because of its predictive weight.
How it shows up on your face: Oxygen delivery to skin is not a metaphor. Capillary density in the dermis, mitochondrial efficiency in keratinocytes and fibroblasts, and the rate at which damaged proteins get cleared all depend on cardiorespiratory capacity. A 2023 controlled trial published in Scientific Reports tested both aerobic training and resistance training in middle-aged sedentary women across 16 weeks and found that both groups significantly improved skin elasticity and upper dermal structure (measured by ultrasound), with documented changes in circulating inflammatory factors and dermal extracellular matrix [7]. This is one of the cleaner pieces of evidence we have that aerobic fitness is, mechanistically, a skincare intervention.
The number to know: A reasonable target for women in their 30s and 40s is 35 to 40 ml/kg/min and higher if you train. Apple Watch, Garmin, and Polar devices estimate this with reasonable validity for tracking trends, though a metabolic cart is gold standard.
The training intervention: Zone 2 work (the boring, conversational-pace cardio that your friends will mock you for) plus weekly VO2 max intervals. Norwegian 4x4 protocols have the most published evidence.
4. Fasting glucose, fasting insulin, and HbA1c
What they actually measure: How well you handle sugar, both right now (fasting glucose), under chronic load (HbA1c, a three-month average), and how hard your pancreas is working to keep glucose down (fasting insulin).
Why they predict aging: This is the one that ties most directly to visible skin aging, and it has a name: glycation. When circulating glucose is chronically elevated, sugar molecules covalently bond to collagen and elastin fibers, producing Advanced Glycation End-products (AGEs). AGEs accumulate in skin with age and are amplified by UV exposure, producing wrinkles, loss of elasticity, dull yellowing, and impaired wound healing [8]. The cross-linked collagen physically cannot do its job. It is stiffer, more brittle, and slower to turn over.
A 2023 retrospective case-control study at an academic medical center, controlling for diabetes and PCOS, found that patients with acne had significantly elevated HbA1c levels compared to controls, suggesting acne patients may have increased prediabetes risk [9]. As many as 65-80% of women with PCOS are estimated to have insulin resistance!
The mechanism is well-mapped: insulin resistance lowers sex hormone-binding globulin (SHBG), increasing free androgen activity, while elevated insulin-like growth factor 1 (IGF-1) directly stimulates sebocyte proliferation and lipogenesis [10].
How it shows up on your face and body: Dermatologists have a category called cutaneous signs of insulin resistance, and it is more extensive than most women realize. The unifying mechanism is that hyperinsulinemia stimulates IGF-1 receptors on fibroblasts and keratinocytes, driving the cell proliferation and tissue changes you can see in the mirror [11]. The most well-documented signs:
- Skin tags (acrochordons), particularly on the neck, eyelids, armpits, and under the breasts. A study cited in the dermatology literature found that having more than 30 skin tags on the body confers a 52 percent risk of developing diabetes, and women with more than 5 skin tags showed a 1.4-unit increase in HOMA-IR (the standard insulin resistance score) [12]. Skin tags are not just a cosmetic nuisance. They are a warning.
- Acanthosis nigricans, the velvety, darkened, slightly thickened patches that show up most often on the back of the neck, in the armpits, and in the groin folds. Often mistaken for “dirty skin that won’t wash off.” It was formally established as a diabetes indicator by the American Diabetes Association in 2000 and is mechanistically driven by insulin-stimulated keratinocyte proliferation [13].
- Sallow, yellowish dullness in the deeper dermis from AGE accumulation, the cross-linked end-products of glycation that physically deposit in collagen fibers.
- Loss of elasticity and bounce that no topical can fix from the outside, because cross-linked collagen has lost its mechanical properties and topical actives cannot reach the deep dermis.
- Persistent hormonal acne along jaw, chin, and lower cheeks, driven by hyperinsulinemia lowering SHBG and elevating free androgens plus IGF-1’s direct stimulation of sebocyte proliferation.
- Oily skin and seborrheic dermatitis, the same sebaceous gland upregulation that drives the acne, often presenting earlier than the breakouts themselves [14].
- Hyperpigmentation that resolves slowly, tied to AGE-induced microvascular dysfunction that impairs the dermal repair process.
- Facial puffiness, particularly around the eyes and along the lower face. Elevated insulin and elevated cortisol both signal the kidneys to retain sodium and water, which shows up as a softer, less defined facial structure that often gets misread as weight gain. The “moon face” you see in someone on long-term steroids is the extreme version of this same mechanism.
- Chronic facial flushing. A 2019 imaging study found that diabetic patients show significantly larger heartbeat-synchronized variations in facial redness compared to healthy controls, suggesting that vascular dysregulation is detectable in the face long before clinical complications set in [15]. Sugar dilates the small vessels under the skin, and chronic dilation eventually coarsens skin texture and contributes to the rosacea-like redness pattern many women blame on “sensitive skin.”
- Hirsutism and androgenic alopecia (thinning along the part line, temples, or crown), which travel with insulin resistance because the same elevated androgens that drive acne also drive terminal hair growth in unwanted places and miniaturize hair follicles in the scalp [16].
The pattern: anywhere your skin is doing something it didn’t used to do (new tags appearing, darker patches in folds, persistent jawline breakouts, redness that won’t quit, scalp showing through where it didn’t before) the question to ask is not which serum to add. It is what is happening with your insulin.
The numbers to know:
- Fasting glucose: optimal under 90 mg/dL (the ADA cutoff of 100 is permissive)
- Fasting insulin: optimal under 7 µIU/mL (most labs flag only above 25)
- HbA1c: optimal under 5.4% (the ADA cutoff of 5.7 is again permissive)
The intervention: These are actually easy markers to fix in that they are very responsive to lifestyle interventions. Walk after meals (a 10 to 15 minute walk after dinner blunts the post-prandial glucose curve more than any supplement). Protein and fiber before carbs. Strength training, which improves insulin sensitivity within 72 hours of a single session. Apple Cider vinegar in water before meals is great. Exercise “snacks” as Dr. Rhonda Patrick suggests. Do all of these things, and, if you need additional support, like I did postpartum when my blood sugar panel came worryingly elevated, you can use The Golden Sequence as needed. All of the markers improved, back to the optimal range, after 6 months taking it and I’ve got the receipts (labs) to share.
5. Lean muscle mass (DEXA or InBody)
What it actually measures: Total skeletal muscle in kilograms, often expressed as appendicular lean mass index (ALMI). Distinct from grip strength because grip is a quality-and-activation metric, while DEXA tells you the absolute amount of tissue you are working with.
Why it predicts aging: Muscle peaks at 30 to 35 in both sexes, then declines slowly until 65 in women and 70 in men, after which the loss accelerates [17]. Postmenopausal women lose appendicular lean mass faster than premenopausal women, an effect tied to estrogen withdrawal and confirmed across multiple studies in a recent systematic review [18].
How it shows up on your face: Muscle mass is the architecture under the skin. The 2023 Scientific Reports trial mentioned earlier showed that resistance training, specifically, increased lean soft tissue mass and improved skin elasticity and upper dermal structure, accompanied by reduced circulating inflammatory factors [7]. The authors concluded that resistance training rejuvenates aging skin by reducing inflammation and enhancing dermal extracellular matrices. That is not a marketing claim. That is a peer-reviewed finding in a respectable journal.
The aesthetic implication is uncomfortable for the wellness industry: facial fillers are filling the negative space that muscle and dermal density used to occupy. The substrate is the substrate.
The number to know: ALMI cutoff for low muscle mass in women is roughly 5.7 kg/m² per the European Working Group on Sarcopenia. A DEXA scan runs about $100 in most US metros. InBody readings are less accurate but sufficient for tracking trends.
The intervention: Progressive resistance training, three sessions per week minimum, with adequate protein (around 1.6 g/kg of bodyweight per day if training).
6. Heart rate variability (HRV) and resting heart rate
What they actually measure: HRV captures the variation in time between consecutive heartbeats, which reflects autonomic nervous system balance. Higher HRV means your parasympathetic (rest-and-digest) system is online. Resting heart rate is its less elegant cousin: a higher RHR usually means a less efficient cardiovascular system and chronic sympathetic activation.
Why they predict aging: A 2019 study in PLOS One found that HRV reduction in healthy young women was directly associated with high visceral adiposity, independent of overall body fat [19]. HRV also tracks tightly with HbA1c (correlation of -0.21 in a recent multi-cohort wearable validation study), depressive symptoms, and sleep quality [20]. It is, in effect, a single number that integrates how your nervous system is metabolizing the demands of your life.
How it shows up on your face: Chronically low HRV signals chronic sympathetic dominance, which means chronically elevated cortisol. Cortisol, in turn, breaks down collagen and elastin, suppresses new collagen synthesis, and impairs barrier function. The dermatology literature is unambiguous on this: chronic stress directly accelerates intrinsic skin aging including fine lines, uneven pigmentation, and reduced elasticity [21]. Add in the sleep disruption that low HRV often signals (and the elevated nocturnal cortisol that comes with poor sleep, particularly in peri- and postmenopausal women) [22], and you have a clean mechanistic chain from autonomic dysregulation to the face in the mirror.
The numbers to know: RMSSD (the most-used HRV metric) varies wildly by individual, so trends matter more than absolute numbers. Track yours for two weeks to establish a baseline, then watch the trajectory. Resting heart rate under 65 bpm is a reasonable target for non-athletes; elite endurance athletes are routinely in the 40s.
The intervention: Zone 2 cardio (the same work that builds VO2 max) is the strongest non-pharmacological lever. So is consistent sleep timing, breathwork (specifically slow-paced breathing at 5 to 6 breaths per minute), and reducing late-evening alcohol, which trashes HRV more than almost any other input.
What this changes about how you train and eat
Notice what is missing from this list: the scale, BMI, calories burned, daily step count, body fat percentage in isolation. Not because those numbers are wrong, but because they are downstream of the metrics above and tell you very little about what is actually happening underneath the skin.
A practical reframe:
Stop optimizing for: weight on the scale, dress size, daily calorie deficit.
Start optimizing for: how much you can carry, how fast you can recover, how stable your blood sugar is across the day, how much muscle you are building per year, how variable your heartbeat is at rest.
The first list is what marketing has sold to women for fifty years. The second list is what the evidence actually says is happening when a body is aging well, with the inevitable consequence that the skin is too.
This is the framework underneath everything we build at Frondescent. Beauty should be thought of as a metabolic indicator. The face is the most observable readout of metabolic health, and the most lagging indicator. By the time something shows up on the surface, the underlying dysfunction has been running for a while. Tracking these metrics is how you catch it early.
References
- Peterson MD, Collins S, Meier HCS, Faul JD. Normalized grip strength is inversely associated with DNAm age in middle age and older adults. Innovation in Aging. 2021. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8682461/
- Granic A, et al. Grip strength and inflammatory biomarker profiles in very old adults. Age and Ageing. 2017. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5860623/
- Dodds RM, et al. Grip strength across the life course: normative data from twelve British studies. PLOS One. 2014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4256164/
- Ross R, et al. Waist circumference as a vital sign in clinical practice: a Consensus Statement from the IAS and ICCR Working Group on Visceral Obesity. Nature Reviews Endocrinology. 2020. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7027970/
- Cleveland Clinic. Visceral Fat: What It Is and How It Affects You. https://my.clevelandclinic.org/health/diseases/24147-visceral-fat
- Strasser B, Burtscher M. Survival of the fittest: VO2max, a key predictor of longevity? Frontiers in Bioscience-Landmark. 2018.
- Nishikori S, et al. Resistance training rejuvenates aging skin by reducing circulating inflammatory factors and enhancing dermal extracellular matrices. Scientific Reports. 2023. https://pmc.ncbi.nlm.nih.gov/articles/PMC10290068/
- Chen CY, et al. Research Advances on the Damage Mechanism of Skin Glycation and Related Inhibitors. Nutrients. 2022. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9655929/
- Not Just Skin Deep: Association of Acne with Elevated Hemoglobin A1c Levels in a Retrospective Case-Control Study of 1098 Patients at an Academic Center. 2023. https://pmc.ncbi.nlm.nih.gov/articles/PMC10719416/
- Kaymak Y, et al. Insulin resistance in the course of acne, literature review. Postępy Dermatologii i Alergologii. 2022. https://pmc.ncbi.nlm.nih.gov/articles/PMC9131965/
- Napolitano L, et al. Insulin Resistance and Skin Diseases. The Scientific World Journal. 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419263/
- Acanthosis nigricans and skin tags as markers of insulin resistance in nondiabetic obese individuals. Journal of Evidence Based Medicine and Healthcare. 2020. https://www.jebmh.com/articles/acanthosis-nigricans-and-skin-tags-as-markers-of-insulin-resistance-in-nondiabetic-obese-individuals.pdf.pdf
- Mayo Clinic. Acanthosis nigricans: Symptoms and causes. https://www.mayoclinic.org/diseases-conditions/acanthosis-nigricans/symptoms-causes/syc-20368983
- Insulin Resistance, Metabolic Syndrome, and Inflammatory Skin Disease. Nutrients. 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12787260/
- Tarnowska M, et al. Invisible Color Variations of Facial Erythema: A Novel Early Marker for Diabetic Complications? Journal of Diabetes Research. 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6745171/
- Prevalence of Clinical Manifestations Known to Be Associated With Insulin Resistance Among Female Medical Students. Cureus. 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11612288/
- Baltimore Longitudinal Study of Aging, summarized in InBody clinical literature.
- Geraci A, et al. The Role of Oestrogen in Female Skeletal Muscle Ageing: A Systematic Review. medRxiv. 2023. https://www.medrxiv.org/content/10.1101/2023.05.18.23290199.full.pdf
- Triggiani AI, et al. Heart rate variability reduction is related to a high amount of visceral adiposity in healthy young women. PLOS One. 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6760781/
- Resting Heart Rate Variability Measured by Consumer Wearables and Its Associations with Diverse Health Domains in Five Longitudinal Studies. 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12693838/
- Chen Y, Lyga J. Brain-skin connection: stress, inflammation and skin aging. Inflammation and Allergy - Drug Targets. 2014. https://pmc.ncbi.nlm.nih.gov/articles/PMC4082169/
- Editorial: The bidirectional relationship between sleep and neuroendocrinology. Frontiers in Endocrinology. 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10853462/