378 ‒ Women’s health & performance: how training, nutrition, & hormones interact across life stages

KEYPOINTS

• 01

  Osteoporosis starts in childhood, so early play and lifting matter

  Peter recalls a prior guest's line that osteoporosis is a childhood disease: women hit their genetic bone-density ceiling around 19 and spend the rest of life defending it. Abbie Smith-Ryan argues for broad, varied play and multiple sports rather than early specialization, plus resistance training as injury prevention — she loved Romanian deadlifts at 11 or 12 — using bands, light weights, plyometrics and med balls.

• 02

  Intense training that delays puberty costs bone, and asymmetric sports leave marks

  Gymnasts, runners, swimmers and cyclists can have delayed periods, often from unintentional underfueling, and that delayed estrogen harms bone. In 15 years of DEXA scanning at UNC, Abbie says nearly every high jumper and gymnast shows a distinct spinal curve, often unknown to them — not fixable at 18–20, but something to stabilize with musculoskeletal work.

• 03

  Young female athletes need to be taught food as fuel

  Rather than food rules, Abbie emphasizes adequate energy, with calorie-dense swaps (whole milk instead of skim, full-fat yogurt, nuts, seeds) for girls who can't eat much before early practice. Exercise blunts hunger, and GI distress — sometimes linked to the menstrual cycle — is common, so intake must be planned. She pushes back on the trend of protein-centric, low-carb messaging for young female athletes.

• 04

  You can train in any cycle phase; women just feel different

  Her lab's data says performance largely holds across the cycle, but women feel worse in the late luteal phase: fatigue, bloating, poorer recovery and soreness. The early follicular phase brings more carbohydrate oxidation and feeling good; late follicular around ovulation is when women typically feel their best. Peak performance seems preserved; recovery is what to manage.

• 05

  Late luteal phase: prepare for the progesterone crash

  Thermoregulation, water retention, inflammation and protein breakdown rise, and resting energy expenditure increases by roughly a couple hundred calories a day — just as women often eat less and the scale rises from water. Strategies Abbie mentions for symptomatic women: 2–3 g omega-3s, zinc and magnesium for sleep, more fruit and vegetables, caffeine (possibly more helpful in this phase) and creatine.

• 06

  Creatine moved fluid into cells in the luteal phase

  Her lab compared phases and found creatine shifted extracellular fluid into the cell, helping with bloating and indirectly performance. Studies load at 20 g/day (four 5 g doses) for 5 days then 5 g/day; she notes midlife and brain-health data go up to 10 g. Peter says after talking with Rhonda Patrick his practice moved maintenance from 5 to 10 g. Abbie cautions creatine is helpful but not magic or the first lever for midlife women.

• 07

  Protein of about 1.6 g/kg removes most cycle concerns

  A paper in review on muscle protein synthesis across the cycle suggests adequate protein (~1.6 g/kg) and amino acids around training make phase differences minor. Peter targets 2 g/kg so that misses still clear 1.6, admitting a week in Asia left him nearer 1.2. Vegetarians or older women should pay extra attention in the luteal phase.

• 08

  Perimenopause is the critical window

  Abbie's work following up on the SWAN cohort finds the biggest changes in metabolism, muscle size and quality, bone and metabolic flexibility occur during perimenopause rather than after. Peter suggests tracking day-5 FSH (day 1 = period start): low when fertile, around 10 signals the transition, 25–50+ in menopause. Abbie's lab also uses daily at-home urine hormone tests to see day-to-day swings.

• 09

  Muscle quality, not just size, declines — 'ribeye versus filet'

  In a two-year longitudinal study, women who followed guidance maintained muscle size but still lost quality (measured by ultrasound and pQCT, consistent with MRI), echoing Australian work by Séverine Lamon. Peter notes whether fat is intra- or intercellular matters for insulin resistance. HIIT improved metabolic flexibility regardless of hormones, and protein around exercise didn't blunt the post-exercise insulin response.

• 10

  Body composition, not weight, should be the goal

  Abbie measures composition (DEXA, multi-frequency BIA or a home scale), aiming for body fat around the 25th NHANES percentile or lower, away from the 50th. For Peter's hypothetical 5'6", 150 lb, 30%-fat 40-year-old wanting 130 lb, she'd suggest ~140 lb, a modest deficit, more fiber, ~30 g protein spaced through the day, and complex carbs. She warns chronic time-restricted eating in midlife can lower metabolism and hurt protein synthesis.

• 11

  GLP-1 drugs demand resistance training and high protein

  On tirzepatide or semaglutide, she'd prioritize lifting and 130–150 g protein (based on goal weight), plus amino acids around workouts. Peter prefers the lowest dose for the longest time (2.5–5 mg tirzepatide over a year); Abbie is studying checking lean mass before titrating up. She flags low energy availability on these drugs can mimic perimenopausal symptoms and may explain bone loss.

• 12

  Power declines first and matters most for falls

  Citing Andy Galpin, Peter calls type 2 fiber hypertrophy central to aging: power goes first, then strength, then size. The stumbled curb is his example of why power matters. Abbie notes women may lose type 2 characteristics faster, and midlife joint pain complicates plyometrics — which Peter believes hormone therapy would often relieve.