Nutrition Trends for Runners in 2023 - She Runs Eats Performs

Episode 127

Published on:

2nd Feb 2023

Nutrition Trends for Runners in 2023

There is SO much information in the media and in magazines about what to eat to enhance running performance….but how much of it is actually evidence-based and factual rather than just being sensationalist?? This plethora of information can lead to confusion for many runners on what to eat to fulfil their running goals.  

Karen, one of your Podcast hosts, attended the ISENC (International Sports and exercise Nutrition Conference) in Manchester in December. This conference is dedicated to outlining and discussing the most up to date science and research in the world of sport and exercise nutrition. 

So, in this episode we share some of that information with you so you feel informed when making YOUR food and nutrition choices to support your run training. The  two principle topics we focus on are:

  • Overtraining Syndrome and Relative Energy Deficit in Sport and how they potentially overlap
  • Dietary Fibre and its potential role in sports performance 



Defining Overtraining Syndrome (OTS) and Relative Energy Deficiency in Sport (RED-S):  

Overtraining syndrome: is viewed as a condition associated with a long-term imbalance between training and recovery and is generally characterized by:

  • Reduced sports performance 
  • Fatigue
  • Mood disturbances 

It is thought to affect between 20% and 60% of athletes throughout their careers.

It is grouped in with functional and non-functional overreaching, but compared to these conditions OTS is the most severe and reflects a chronic accumulation of training and non-training stressors that can take months to years to fully recover from.

Relative Energy Deficiency in Sport: In 2014 the International Olympic Committee (IOC) defined RED-S as:

“….a syndrome resulting from relative energy deficiency that affects many aspects of physiological function…..”  

and this is thought to be as a result of inadequate energy intake (EI) compared to energy expenditure of exercise (EEE) and daily living, resulting in poor health and reduced sporting performance


Establishing the possible overlap between these two conditions:

Current research is focusing on low energy availability (LEA) being what underpins both conditions

Note: LEA = inadequate energy intake (EI) compared to energy expenditure of exercise (EEE) and daily living

There also appears to be symptoms common to both conditions including:

  • Poor performance
  • Poor recovery from training
  • Fatigue
  • Mind/mood symptoms


Uncovering the latest research on the use of dietary fibre to enhance sports performance. 

Studies have revealed that limiting fibre intake could reduce the diversity of an athlete’s microbiota as well as reducing the health of an individual’s gut bacteria. 

Additionally, current research has shown that Short Chain Fatty Acids (produced from the fermentation of certain dietary fermentable fibre by the gut bacteria) appear to support sports performance both directly and indirectly.

Note: Fibre is fermented into SCFAs in the large intestine by specific bacteria called Saccharolytic microbial species. The 3 key SCFAs produced are called Acetate, Proprionate and Butyrate and produced in a ratio of 60:20:20 respectively. 


Outlining ways in which Short Chain Fatty Acids are thought to support sports performance:

  • All three are thought to increase overall energy expenditure
  • All three are involved in altering substrate oxidation (increasing fat metabolism/oxidation and reducing CHO metabolism) therefore possibly helping preserve glycogen stores
  • It has been found that Acetate is the most important of the SCFAs as an energy source in skeletal muscle (during endurance exercise) 
  • SCFAs are thought to help protect muscle mass…again Acetate is thought to be the most important SCFA here.  As we age muscle mass reduces, therefore an increased intake of fibre in older age may help protect SCFA status, thus help protect muscle mass as we age 
  • Some lactate that we naturally produce during exercise is returned to the gut where it is converted back into SCFAs by Vioenella bacteria…so, helping provide additional SCFAs!.  


Highlighting some additional ways in which fibre may support sports performance either directly or indirectly. It may:

  • Lower body mass
  • Increase lean muscle mass
  • Improve glucose balance
  • Increase muscle strength



  • It is important to remember that the information on nutrition in sports and exercise is forever evolving, which means we need to keep up to date with the latest evidence-based data
  • For many, this constant change can lead to confusion on what is the correct food and nutrition choices for their individual health and running needs 
  • There is SO much information out there in the media, but how much of it is evidence based and factual rather than being sensationalist?? This can add to people’s confusion and potentially lead to them making the wrong choices! 
  • Remember OTS and RED-S are conditions that any runner could inadvertently develop due to a lack of understanding of their energy needs, resulting in Low Energy Availability for health and training
  • Dietary Fibre is known to have many general health benefits, but for sports performance: it may support some individuals, but be detrimental to others. When consuming any fibre rich foods around training: start low and build up to help reduce the risk of any detrimental effects on training and performance
  • If you are feeling confused about much of the information out there on social media and magazines about what you SHOULD and SHOULDN’T be eating for your running then get in touch with us at where we can have a conversation with you and try to alleviate any concerns you may have

Related Topics:

The Performance Effects of Overtraining Syndrome

Eating Enough to Run

Spotlight on Probiotics for Performance


The suggestions we make during this episode are for guidance and

advice only, and are not a substitute for medical advice or treatment.

If you have any concerns regarding your health, please contact

your healthcare professional for advice as soon as possible.

Aileen Smith and Karen Campbell host RUNNERS HEALTH HUB. A place for like-minded female runners who are looking for simple ways to support running performance, energy, endurance, and general great health.

if this is your first time your show and you’d like to know more about us and She Runs Eats Performs please check out our TRAILER.

If you're ready to make learn more about how you may introduce easy nutrition into your running and training plan join our Easy Nutrition For Healthy Runners Online Programme for short videos, recipes, downloads and LIVE training and Q&A.

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Happy Running!

Aileen and Karen 


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About the Podcast

She Runs Eats Performs
for mid-life female runners of all abilities
Are you confused about the science around nutrition for runners? Listen in to learn about the WHY, HOW, WHAT, and WHEN of eating to fuel your running performance.

We are here to help you translate sports nutritional science, into easy to apply tips and plans, helping you enjoy peak running performance. We focus on the FEMALE FACTORS every mid-life woman needs to know to be a healthy runner.

About your host

Profile picture for Aileen Smith

Aileen Smith

Nutritionists, Educators, Podcasters, Runners and Friends

We have a love of running and a passion for nutrition, delicious food and healthy living. She Runs Eats Performs for female runners of all abilities who are looking for simple ways to improve their running performance and their health with nutrition and lifestyle.
We enjoy sharing our nutritional expertise, reviewing the latest sports science and most of all helping you to take easy action so you can enjoy your running life to the full.
We are here to help you achieve great health and good shape whilst staying injury-free with easy-to-understand sports nutritional concepts and easy-to-implement tips and plans.

Aileen and Karen are BANT and CNHC Registered Nutritional Therapists.