The RED light to your performance goals

News and Updates

by Dr. Nikita Fensham

I’m a medical doctor. A qualified performance nutritionist. An athlete. And a PhD researcher in this field.

And I have RED-S.

I know what it’s like. To love sport, to be a perfectionist, to have performance goals. To become consumed by being better, the best. To forget about the health consequences. To think that it’s a worthwhile sacrifice, just for now.

I also know what it’s like when that mindset backfires. When the effects on health put an abrupt end to performance. When years of having no period, of chronic fatigue, of unrelenting psychological stress, of insomnia, of social isolation, of flatline moods… all catch up. Paces drop, FTP’s become stagnant, PR’s become impossible.

And because I know what it’s like… I’m here to help. I’m here to stop the silence, to echo the stories of so many athletes like me, to tell you that you’re not alone. To encourage a new culture in sport where we achieve both performance AND health.

What is RED-S?

RED-S stands for Relative Energy Deficiency in Sport, which aims to describe the various disruptions in body systems that occur when an athlete does not fuel adequately to meet both the demands of their training as well as the requirements of their organs to function optimally. It was built off the original “Female Athlete Triad” which centred around females who exhibited amenorrhea (i.e. no period by the age of 15 or missing three consecutive periods), low bone density, and low energy availability or disordered eating. Recognising that males also suffered from the consequences of inadequate fuelling, it was deemed necessary to come up with a term that not only included both sexes but also acknowledged that there were other health and performance effects beyond reproductive function and bone density.

Although more research needs to be done (emphasising the importance of speaking out about this issue!), it seems that the body responds with a general shutdown. In the beginning, many athletes see performance improvements, ironically, as the body prioritises the nutrients to sustain training… to the detriment of the organs that just cannot function optimally. As a result, athletes experience a reduction in metabolism, absent or irregular menstruation patterns, lack of morning erections, increased injuries and illness, increased stress fractures due to weak bones, low mood and excessive fatigue, and constipation. Eventually, performance suffers too with the inability to recover from and adapt to training resulting in a slower, weaker, and less resilient athlete. It’s like your body becomes the rebellious teenager: once you’ve restricted it’s function too much or too long, it responds by kicking you where it hurts most… the ability to perform in your sport.

Why should you care?

It seems obvious, right? I need to be healthy to perform at my best! But strangely it isn’t that obvious and there are most certainly many athletes who suffer in silence. This may be because they feel pressure from coaches, the sport culture, social media, or peers to look a certain way or achieve a certain body composition, or it may be because they simply don’t know that they’re getting it wrong! It’s difficult… not only to measure how much you might be expending and taking in in a day, but also to manage all of this on top of life stuff!

Personally, I haven’t had a period in five years… but I’m a doctor. I should know better. Unfortunately, we don’t always. Medical education prepares you to deal with dire emergencies, with chronic disease, with infections… not athletes. It was only when I started pursuing my own education in sports medicine and performance nutrition that I truly understood this physiology. My own gynaecologist even prescribed the oral contraceptive pill back in the day to “kick start” my cycles (which, by the way, is completely wrong… an article for another day). But even then, with improved understanding, I put it on the back-burner. Working as a doctor in South Africa, I was always stressed. High patient-load burdens, shifts that ran into 28 hours on the trot, often no gap for lunch during the day… worrying about my own health wasn’t a priority. And strangely, I thought I was still performing in my sport.

Until it hit the fan. This year I developed diffuse swelling, first in my feet and eventually in my abdomen and face… for the first time, I became a patient. My albumin levels (protein in the blood) were low, and this causes the fluid part of blood to shift from your blood vessels into your tissues (“oncotic pressure” for the nerds). I was chronically fatigued, my moods were always just “flat” without highs or lows, and, although I was fortunate to not have suffered any significant injuries, my performance tanked. My swim and run times got slower, my FTP on the bike dropped, and I couldn’t lift the weights that I used to be able to. When I look back, it was a slow decline that I just failed to notice. And, unfortunately, it took a serious wake up call to kick me into action and do something about it.

So what do you do?

Firstly, you speak up. There’s no shame in admitting that things aren’t always rosy. I have the qualifications and I got it all wrong; I failed to look after myself. By speaking up and sharing experiences, we discover more about what happens to health and performance, we pick it up earlier and prevent others from following the same trajectory, we educate athletes, coaches, and doctors, we change the culture, and ultimately we raise performance by being healthy first. I’m speaking up… I neglected my own body… and I paid the price in declining performance.

But now I’m doing something about it. This year, I stepped back from hard training to get my health on track, to prioritise nutrition, sleep, and mindfulness practice; I applied what I, ironically, already knew. In a few weeks, the swelling completely resolved, I got my appetite signals back, I started sleeping better, my sense of humour returned… and, not surprisingly, I’m stronger on the bike, and the kettlebell I bought for lockdown already feels light!

This is a lifelong journey for me and there is no quick fix, magic bullet, glorious epiphany, or simple switch. It’s an everyday commitment to conscious practice of theoretically simple, yet often neglected, principles of sensible training, complete nutrition, quality sleep, and psychological inquiry. It is also a daily acknowledgement of imperfection, of being okay with making mistakes, of asking for help when needed. Athletes, by nature, are dedicated to achievement, to ticking green boxes, to crossing I’s and dotting T’s… often a contributing factor to landing up in a situation of RED-S. But here’s the kicker: celebrate it. That part of your personality also contributed to your being successful in your life. And it is the same part of you that can turn situations around. Channelling my drive for achievement into health, into better routines, into introspection gave me improved performance in life and in sport as a corollary.

I transitioned from medical practice into a PhD this year to pursue my passion for this area of sport, where nutrition meets medicine. I want to change the landscape where athletes’ performance goals are underpinned by a healthy body and mind, where coaches ask about periods and erections, where doctors don’t automatically prescribe the pill for missing periods in athletes, where good nutrition and optimal hormonal function are recognised for their “legal doping” effects.

I am incredibly grateful for this experience and the opportunities I have to make a dent in this space going forward. Navigating this journey personally, and having to apply my professional background to practice, I feel that I am now in a privileged position to guide athletes through this maze.

If you think you already have symptoms or may be heading down the path of RED-S, speak up. Join the crowd. Find support. You’re not alone.

And if you don’t know where to go or what to do, email me ( Whether you want to share your story, be a part of a bigger movement, or seek help from a network of professionals… I’m here to help in any way that I can.

Useful resources:

IOC Consensus Statement: Mountjoy M, Sundgot-Borgen J, Burke L, Ackerman KE, Blauwet C, Constantini N, et al. International Olympic Committee (IOC) Consensus Statement on Relative Energy Deficiency in Sport (RED-S): 2018 Update. Int J Sport Nutr Exerc Metab. 2018;28(4):316-31.

shaREDex website:

British Association of Sports and Exercise Medicine:


This article should not be considered medical advice and is instead intended to be the opinions of the author. Always seek independent medical advice before making any decisions based on your health.


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