You’re training hard.
You’re eating “clean.”
You’re doing everything right.
So why are you exhausted, flat, and stuck?
In this episode of The Fundamentals of Fitness, Alison explores one of the most overlooked drivers of progress: energy availability.
This isn’t about eating recklessly or abandoning fat loss. It’s about understanding how your body reallocates energy under stress — and why chronic under-fuelling can stall fat loss, suppress hormones, and compromise performance.
You’ll learn:
What energy availability actually means (and how it differs from calorie deficit)
The physiological cascade of low energy availability
Why thyroid output, reproductive hormones, and NEAT shift under chronic restriction
The early warning signs of under-fuelling
How to restore balance without swinging to extremes
Because performance isn’t built on pushing harder.
It’s built on fuelling intelligently.
✅ ACTION STEPS
If you suspect low energy availability:
Audit your fatigue levels honestly.
Review sleep consistency for 10–14 days.
Assess whether training load has increased recently.
Increase intake modestly (150–300 kcal), particularly around training.
Maintain protein intake.
Consider reducing training intensity temporarily if recovery is poor.
Track biofeedback (sleep, mood, cycle, libido, performance) — not just the scale.
Avoid dramatic overcorrection.
Stabilise first.
Then progress.
🔗 CONNECT WITH ALISON
For no-nonsense fitness, training, and mindset support, you can find me here:
Instagram: @abperformancetraining
TikTok: @abperformancetraining
Facebook: AB Performance Training & Coaching
Website: abperformance.training
⚠️ DISCLAIMER
The information shared on The Fundamentals of Fitness podcast is for educational purposes only and should not be taken as medical advice. Always consult a qualified healthcare professional before making changes to your training, nutrition, or health routines.
REFERENCES
Burke, L.M., Lundy, B., Fahrenholtz, I.L. and Melin, A.K. (2018) ‘Pitfalls of conducting and interpreting estimates of energy availability in free-living athletes’, International Journal of Sport Nutrition and Exercise Metabolism, 28(4), pp. 350–363.
De Souza, M.J., Koltun, K.J., Williams, N.I. and Joy, E. (2019) ‘The role of energy availability in reproductive function in women exercising for weight control’, Human Reproduction Update, 25(4), pp. 445–468.
Fagerberg, P. (2018) ‘Negative consequences of low energy availability in natural male bodybuilding: a review’, International Journal of Sport Nutrition and Exercise Metabolism, 28(4), pp. 385–402.
Mountjoy, M., Sundgot-Borgen, J., Burke, L., et al. (2018) ‘IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update’, British Journal of Sports Medicine, 52(11), pp. 687–697.
Müller, M.J., Enderle, J. and Bosy-Westphal, A. (2016) ‘Metabolic adaptation to caloric restriction and subsequent refeeding: the Minnesota Starvation Experiment revisited’, American Journal of Clinical Nutrition, 102(4), pp. 807–819.
Nattiv, A., Loucks, A.B., Manore, M.M., et al. (2007) ‘American College of Sports Medicine position stand: the female athlete triad’, Medicine & Science in Sports & Exercise, 39(10), pp. 1867–1882.
Pontzer, H. (2015) ‘Constrained total energy expenditure and metabolic adaptation to physical activity’, Current Biology, 25(19), pp. R776–R784.
Speakman, J.R. and Mitchell, S.E. (2011) ‘Caloric restriction’, Molecular Aspects of Medicine, 32(3), pp. 159–221.