Mechanism
Hormonal reference ranges are established from population samples that include individuals with undiagnosed hormonal disorders, sedentary individuals, and those at varying health states. For athletic women, "normal" is often insufficient. Additionally, cycling hormones must be measured at specific cycle phases to be interpretable — Day 3 FSH/LH/estradiol (follicular phase baseline), Day 21 progesterone (peak luteal production), free testosterone at any point. A Day 21 progesterone below 10 ng/mL in a woman complaining of PMS and poor luteal phase sleep is clinically meaningful even if flagged as "within normal limits" by the lab.
Signs & Symptoms
- WHEN TO TEST: Day 3 of cycle (Day 1 = first day of period) — baseline FSH, LH, estradiol, AMH
- WHEN TO TEST: Day 21 of cycle (or 7 days post-ovulation) — progesterone, estradiol
- WHEN TO TEST: Any day — fasting insulin, HOMA-IR, fasting glucose, TSH, Free T3, Free T4, Reverse T3, testosterone (total and free), SHBG, DHEA-S
- WHEN TO TEST: Day 2–5 for PCOS panel — LH, FSH, testosterone, prolactin, 17-hydroxyprogesterone
- FASTING REQUIRED: Insulin, glucose, lipid panel — minimum 10 hours fasted
Stages
Prevention
- Establish baseline labs before starting any compound, supplement protocol, or significant training change
- Retest 8–12 weeks after any intervention to assess response
- Note menstrual cycle day on every lab requisition — essential for hormonal interpretation
Management Protocol
- OPTIMAL TARGETS FOR ATHLETIC WOMEN:
- TSH: 1.0–2.0 mIU/L (optimal for athletes, not just 0.5–4.5 normal)
- Free T3: Upper third of reference range — typically 3.5–4.2 pg/mL
- Estradiol Day 3: 25–75 pg/mL
- Progesterone Day 21: above 10 ng/mL (above 15 is ideal)
- Free Testosterone: 1.5–4.0 pg/mL (lower end in women without androgenic symptoms)
- SHBG: 40–80 nmol/L (very high SHBG crashes free testosterone)
- Fasting Insulin: under 8 mIU/L (optimal), under 10 (acceptable)
- HOMA-IR: under 1.5 (optimal), under 2.0 (acceptable)
- Vitamin D: 40–60 ng/mL (not just 20 ng/mL "sufficient")
- Ferritin: above 50 ng/mL for athletes (not just 12–15 ng/mL "not anemic")
Risk by Compound
| Compound | Risk Level | Notes |
|---|---|---|
| Any compound use | Lab essential | Baseline before starting, mid-cycle at 4 weeks, and 8 weeks post-cycle minimum. |
The difference between "normal" and "optimal" labs is the difference between surviving and performing. A ferritin of 14 ng/mL will not show anemia on a CBC but will absolutely crush your training. A TSH of 4.0 is within normal limits but will leave you exhausted and stalled. Know your numbers. Know what they mean for performance, not just disease absence.