Stronger with Time

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Most people who train seriously have heard the word periodization. Far fewer understand what it actually is, or how to use it to get more out of every year of training. In this episode, one of the world's leading authorities on the subject explains exactly that.

Professor Greg Haff completed his doctoral work under Professor Mike Stone and has spent decades coaching Olympic athletes, military personnel, and elite strength and power competitors, while publishing over 270 scientific papers on training adaptation.

In this episode, Professor Haff explains:
What periodization actually is and why confusing it with programming is one of the most common mistakes coaches make. Periodization is an organisational strategy. Programming tactics sit inside it.

The three periodization models — parallel, sequential, and emphasis — and how goal and context determine which one applies. Most recreational trainees benefit from an emphasis model that varies the density of each training component across the week.

Why changing the training stimulus every four to five weeks prevents accommodation and what the historical and modern research consistently shows about why this window matters for large muscle group exercises.

How to sequence strength and hypertrophy phases to get more from both and why building work capacity first creates the foundation to lift heavier loads when you return to hypertrophy training.

Why volume load, not set count, is the primary driver of muscle growth and how cluster sets allow higher loads, greater time under tension, and more total work than conventional set structures.

How psycho-emotional stress compounds training stress and why periodization is fundamentally a fatigue management process that has to account for everything happening in a person's life, not just what happens in the gym.

Key insight:
The best coaches in the world have always used some form of periodization model. Most of them are not on social media. Structure, variation, and fatigue management remain the variables that separate long-term progress from stagnation.

Topics: periodization, program design, hypertrophy, strength training, phase potentiation, cluster sets, training volume, fatigue management, periodized nutrition, long-term athlete development, resistance training, ageing and exercise

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The most prominent female fitness trends of 2025-26 are heavily hormone-focused. Most take something biologically true — estrogen fluctuates, cortisol rises during exercise, fibre type differs slightly between sexes — and build a training recommendation on it that the outcome data doesn't support. In this episode, Dr. Lauren Colenso-Semple evaluates those claims against the actual research.

Dr. Lauren Colenso-Semple completed her PhD at McMaster University under Professor Stuart Phillips, with research focused on strength and performance across the menstrual cycle.

In this episode, Dr. Colenso-Semple explains:
How cycle syncing originated — from rodent ovariectomy studies involving full hormone shutdown to a large extrapolated jump into popular fitness content, and why reducing training volume to align with cycle phase conflicts with what the research shows about long-term volume-dependent adaptation.

Why sex differences in muscle fibre type are very small in untrained people, adaptive with training, and secondary to athlete calibre — and why mitochondrial adaptations are a function of training status rather than sex or age.

Why mechanical tension, achievable across a wide rep range, is the primary driver of muscle growth — and why this holds in men and women of all ages and training backgrounds.

The distinction between Cushing's syndrome, a clinical condition involving chronic cortisol dysregulation, and the normal acute cortisol fluctuations that occur during exercise — and why conflating the two has led to widespread unnecessary concern.

Why the kisspeptin argument against fasted training for women comes from a rodent receptor deletion model and has not been replicated in human outcome studies.

Why the apparent ease with which male partners lose weight relates to differences in body size and maintenance calorie intake rather than a sex-specific metabolic response to a calorie deficit.

Key insight:
The hormone-based fitness claims most frequently directed at women tend to draw on mechanistic or animal data, while the long-term outcome studies — which address the actual goals of interest — show no meaningful sex difference in training response.

Topics: cycle syncing, zone two training, female fitness trends, fibre type, mitochondria, cortisol and exercise, Cushing's syndrome, fasted training, kisspeptin, rep ranges, menopause and strength training, estrogen and muscle, mechanical tension, training volume, calorie deficit, evidence-based training

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The fitness industry prescribes energy deficits without the framework to know when a deficit becomes harmful. This episode translates the RED-S research into practical application for coaches and individuals working on body composition.

In this episode we breakdown the key concepts from recent conversation with Professor Louise Burke.

You'll learn:
Low energy availability (the exposure) vs RED-S (the syndrome) - why the distinction matters for application

Why fat-free mass, not total body mass, is the correct denominator for energy availability

The threshold numbers: ~20 cal/kg FFM for fat loss; below 15 cal/kg FFM where adverse consequences are well-documented

Which systems are affected first - reproductive hormones and bone turnover - and how quickly (research shows within five days at 10 cal/kg FFM, which the transcript notes is not uncommon in physique sport)

Why metabolic adaptation is a consequence of RED-S, not a separate phenomenon

What the evidence does and doesn't support on sex differences in fasted exercise, including the kisspeptin hypothesis

Why fasted training and low energy availability are not the same thing

The 2023 RED-S questionnaire toolkit

Prevention: returning to energy balance (30–40 cal/kg FFM) one to two days per week

Recovery: stepwise calorie increase and gastrointestinal adaptation

Key insight: Low energy availability is the exposure; RED-S is the syndrome.
Fasted training is not the same as low energy availability.
These distinctions are foundational to applying this research correctly.

Topics: RED-S, low energy availability, fat-free mass, metabolic adaptation, fasted training, kisspeptin, body composition, physique sport, Louise Burke, Stronger With Time

RESOURCES & LINKS
Dr Tony Boutagy → tonyboutagy.com

Professor Louise Burke - Australian Catholic University → https://www.acu.edu.au/research-and-enterprise/our-research-institutes/mary-mackillop-institute-for-health-research/our-people/louise-burke

IOC RED-S CAT 2 Tool (PDF) → https://stillmed.olympics.com/media/Documents/Beyond-the-Games/Health-and-Wellbeing/2023-IOC-REDS-CAT2.pdf

IOC 2023 Consensus Statement on RED-S → https://pubmed.ncbi.nlm.nih.gov/37752005

Sports Dietitians Australia → https://www.sportsdietitians.com.au

Polar H10 heart rate monitor → https://www.polar.com/en/sensors/h10-heart-rate-sensor

🌐 Visit → https://tonyboutagy.com/
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If you've experienced unexplained fatigue, lost your period, or can't build muscle despite training hard - this episode will help you understand why.

Professor Louise Burke - IOC expert panel member on RED-S - explains the complexity behind low energy availability, why it's being oversimplified on social media, and why context matters more than rigid rules.

You'll learn when energy deficit becomes problematic, which body systems are affected first (and why), why stress makes everything worse, and whether the fasted training fears are actually supported by evidence.

We also discuss Professor Burke's groundbreaking Melbourne study using the only metabolic chamber in the Southern Hemisphere to compare diet-induced versus exercise-induced energy deficits.

In this Episode:
The difference between low energy availability (exposure) and RED-S (syndrome)

Why energy deficits aren't always intentional (training volume, time constraints, budget)

Which body systems are affected: reproductive, bone, GI, metabolism, performance

Why some systems shut down before others (evolutionary perspective)

Stress as a major amplifier of symptoms

RED-S CAT 2 clinical diagnosis tool (requires medical expertise, not self-diagnosis)

Evolution from Female Athlete Triad to RED-S (males affected, multiple systems involved)

Cultural issues in endurance sports (Tour cyclists surviving on coffee for 7-hour rides)

Does the method of creating deficit matter? Diet vs exercise-induced

Melbourne metabolic chamber study: comparing both methods (results expected 2027)

Fasted training controversy: insufficient evidence for rigid rules

Sex differences in sensitivity to energy rhythm (confounded by stress factors)

Louise's perspective: better to exercise fasted than not exercise at all

Key insight:
RED-S is far more complex than simple numerical thresholds. Context, individual variation, stress, and the method of creating deficit all matter. Oversimplified social media advice may cause more harm than good.

Melbourne Study:
Professor Burke is recruiting runners, triathletes, race walkers (50k+/week) for a study comparing exercise-induced vs diet-induced energy deficit using the only metabolic chamber in the Southern Hemisphere. Results expected 2027.
Contact  ⁠[email protected] for recruitment information.

Go straight to the redcaps screening tool   https://redcap.link/acu-agility

Topics: energy deficit, undereating, overtraining, hormones, bone health, metabolic adaptation, female athlete triad, amenorrhea, stress fractures, fasted training, sports nutrition

What started as 6 planned episodes became 31 conversations throughout 2025. This is my year-end reflection on the final five conversations - and the one consistent message that emerged from every expert.

The core message:
Individual variation matters more than sex-specific protocols. Training principles apply to human physiology, not gender categories. What you do consistently shapes who you become.

Key insights from 2025:
💡 You are what you do repeatedly" - Professor Sophia Nimphius. Your training history shapes your physiology more than your sex does.
💡 Research + coaching perspectives both matter. Research shows what works on average. Coaching finds what works for you.
💡 The public message has become too complex. 80% of women aren't lifting weights, yet the advice has become increasingly segmented and contradictory.
💡 Training frequency: The pre-steroid era (1800s-1950s) used 2-3x per week full body training. Modern muscle physiology supports this approach for natural lifters.
💡 Menopause care is patient-centered. History, symptoms, and goals drive treatment decisions - not blanket "every woman should" recommendations.
💡 Low energy availability is the hidden epidemic in midlife women. Even 35-year-olds are showing perimenopausal symptoms from chronic under-fueling.

Brief highlights from 5 conversations:
🎙️ Round Table (Paul Laursen, Jake Doleschal, Dana Lis): How strength, endurance, and nutrition interact in real life. Why zones are coaching prescription tools, not gender-specific protocols.
🎙️ Jake Doleschal: Training frequency and the muscle fiber-specific nature of hypertrophy. Why first sets give you 50% of stimulus with diminishing returns after.
🎙️ Dr. Nadya Chami: What happens in a menopause consultation. Individualized hormone therapy decisions based on patient needs and contraindications.
🎙️ Professor Abbie Smith-Ryan: Context matters for fasted training. Fueling around training sessions for better body composition. Why short-term studies miss real-world complexity.
🎙️ Professor Sophia Nimphius: Research quality issues (85% of top meta-analyses contain errors). The circle of resistance training life. Why more overlap exists than difference between male and female training responses.

📅 2026 plans: Body composition focus, continued women's health and performance, and the experts doing the actual research.

If you found this valuable, follow for more evidence-based insights in 2026.