Female Training, Hormones & Nutrition: What the Science Shows

I recently sat down with Dr. Lauren Colenso-Semple to explore what the evidence actually shows about female physiology, the menstrual cycle, hormones, and training — and why the findings should make things simpler, not more complicated. Listen to the full episode here.

Why Female-Specific Programs Often Miss the Point

The most important variables in any training program are your goals, experience level, time, equipment, and what you will actually do consistently. Sex falls very far down that list.

There is a lot of messaging right now claiming women need cycle-specific programming, phase-adjusted rep ranges, or fundamentally different training principles. The problem with lumping all women into one bucket:

• It throws out individualization — the thing that matters most
• It ignores that a powerlifter, a marathon runner, and someone training for general health need entirely different programs — not because of their sex, but because of their goals
• It can create unnecessary complexity and anxiety that gets in the way of the boring basics that actually work: consistent, challenging, progressive training

The research does not support female-specific training recommendations. That is not a dismissal — it is genuinely good news.

The Menstrual Cycle and Training

What actually happens (vs. the textbook)

The textbook 28-day cycle with ovulation at day 14 is not what most women experience. Across multiple cycles of rigorous hormone tracking, the reality is:

• Cycle length ranges from 21 to 35+ days — all potentially normal
• Ovulation timing varies independently of cycle length — one participant with a 30-day cycle ovulated on day 9 consistently; another ovulated on day 19
• Hormone peak magnitude varies enormously between women, and even between cycles in the same person
• Apps that say “you’re in your luteal phase, do this training” are often guessing — you don’t know what phase you’re actually in without testing

What the science shows

• Strength, speed, and power show no meaningful differences across the menstrual cycle on average
• Muscle protein synthesis — the mechanism underlying muscle growth — also shows no difference by cycle phase, according to Lauren’s published research, a rigorously controlled study using isotope tracers across both follicular and luteal phases
• The estrogen-as-anabolic hypothesis came from rodent models where the ovaries have been removed — an extreme, non-physiological condition that does not translate to normal human hormonal fluctuation

What this means in practice:

• Do not make preemptive changes to training based on cycle phase — doing so is potentially harmful and may hold you back
• Do use autoregulation if you experience significant symptoms on certain days — reduce load or volume as needed. That is just good, individualized coaching applied to any athlete

Hormones and Muscle: Clearing Up the Confusion

• Testosterone in women is at minimum 15-fold lower than in men — at concentrations so small that most standard lab assays cannot accurately detect them
• Men and women gain strength and muscle at the same relative rate when training properly — this holds across all ages
  • At the absolute level, starting points differ (testosterone during puberty established that baseline), but relative gains are equivalent
• This equivalence tells us that fluctuations in estrogen, progesterone, or testosterone within a normal range are not the key drivers of hypertrophy
  • If they were, women with larger hormone peaks would be more muscular. They are not.
  • Performance would vary systematically by cycle phase. It does not.
• Testosterone within a normal range — even if yours is higher or lower than someone else’s — does not predict who will build more muscle or strength

Menopause: What Actually Changes

• Strength: Nothing changes due to menopause per se
• Muscle size: Same — no change independent of lifestyle
• What does change: Roughly 60–70% of women gain body fat during the menopause transition
  • If it appears that muscle has been lost, it is usually that fat mass increased without a matching gain in muscle — two different levers
  • The SWAN study, which followed women longitudinally through the transition, showed muscle mass is fairly stable across the menopausal period
• Hormone replacement therapy: Studies show no difference in lean mass between women on estrogen therapy and those who are not — estrogen replacement is not preserving muscle the way early rodent models suggested

The more important message: it is never too late to start. People who have never exercised and begin resistance training at 75 still build muscle. If you want to arrive at the menopause transition in the best possible position, build the foundation now — the fitter and stronger you arrive, the better you will fare on the other side.

How to Train

The recommendations are the same regardless of sex — as I’ve covered in depth here:

• Train close to failure. Whether you do 6 reps or 15, your last rep should feel like you could only do 1–2 more. If you are not there, the load is not heavy enough.
• There is no must-do exercise, rep range, or training day count. Resistance training offers enormous flexibility — adjust for equipment, injury, preference, and goals without losing effectiveness.
  • As Dr. Bret Contreras put it: the main sex difference he sees in coaching is preference — women tend to want more glute work, men more upper body. Goal-oriented programming, not physiology.
• Consistency and progressive overload are non-negotiable. As you get stronger, load must increase.
• Give a program enough time. Most people switch too quickly. Two months minimum; three to four is better. Early results from any new program are inflated — don’t mistake that for the program being uniquely magical.
• Change one variable at a time when experimenting. Keep everything else stable long enough to actually evaluate what is working.
• For fat loss: nutrition is the driver. A calorie deficit works for everyone, regardless of sex or age. Do not expect exercise alone to do the heavy lifting.

Don’t rely too heavily on any one creator. Seek a variety of perspectives, and don’t change something that is working just because it is not endorsed by whoever you follow online. If you are making progress toward your goals, it is working — stick with it.

Remember: in the words of Bill Bowerman, “If you have a body, you are an athlete.”

- Andy