Study: Sleep & Nutrition Interactions

03 Mar 2020
Caroline O'Mahony

Sleep and Nutrition Interactions: Implications for Athletes

Sleep has long been regarded a key component of a healthy lifestyle. In the world of sports performance, sleep is also a vital part of the athlete’s recovery process.

Performance Nutritionist with the Sport Ireland Institute, Ronan Doherty, has been studying the interactions of nutrition and sleep and the implications for athletes as part of his PhD at Northumbria University.

The overall aim of the Performance Nutrition team at the Sport Ireland Institute is to develop and integrate personal eating and drinking plans, which maximise athletes’ ability to train and perform to the best of their ability.  Ronan and his colleagues work closely with the various teams at the Institute including strength and conditioning, doctors and physiologist to develop fully integrated plans for athletes to ensure nutritional interventions are precisely calibrated to meet the demands of the athlete.  

Ongoing research studies and reviews ensure the team are providing up to date and accurate information to their athletes and are at the cutting edge of sports nutrition in Ireland.

There are four key bodies involved in the study, Northumbria University, University of Limerick, Letterkenny Institute of Technology and Sport Ireland Institute. The supervision team is made up of Dr Sharon Madigan, Head of Performance Nutrition Sport Ireland Institute, Dr. Giles Warrington, University of Limerick, and Professor Jason Ellis from Northumbria University.


Can you give a brief outline of the study?

Ronan Doherty (RD): The study looks at sleep for athletes. Sleep is a key part of athlete recovery and within that we are investigating the implications and the interactions of nutrition with sleep. So how an athlete may incorporate certain things into their diet to help them sleep and help their recovery.

What were the findings of this study?

RD: We found that there are a range of nutrients that interact with sleep. There are a range that help with sleep called tryptophan enriched proteins so things like milk, turkey, pumpkin seeds. Other things such as caffeine and alcohol can negatively impact sleep and larger food portions late in the evening or in that final meal of the day we know can affect sleep and reduce the amount of sleep people get.

Why is this study important to the Sport Ireland Institute?

RD: Sleep is identified in research by athletes as an important recovery modality. We wanted to look at practical ways that we could promote athlete sleep and thus promote recovery.

If an athlete is not getting enough sleep their recovery from every training session is hampered. They will start to see their performance suffer because they are not getting adequate recovery.  We must look at other things as well, for example nutrition and other physiological recovery modalities. Everything comes together to impact their sleep, if they are not getting enough sleep their performance is going to be affected.

Is this research only applicable to athletes?

RD: No, the findings of this study can be applicable to the public as well. Everyone needs good sleep to function. Our day-to-day life will be affected if we are not sleeping properly. This information is tailored specifically towards athletes, we are looking at foods that they can consume and incorporate into their diet to promote sleep however, anyone can use this to help improve their own sleep.

What are the top three takeaways for someone looking to improve their sleep?

RD: In brief, the top three things to remember are:  

  1. Caffeine can really impact sleep. We know that caffeine intake can increase how long it takes you to fall asleep and it affects the amount of sleep you get. Try not to consume caffeine after 4pm.
  2. We know that high GI carbohydrate in the evening meal or the last meal of the day, dinner helps sleep and helps you fall asleep more quickly
  3. There are lots of other options as well such as kiwi fruit, tart cherry juice and tryptophan rich proteins so milk, pumpkin seeds and turkey. We also know that jasmine rice promotes sleep.
What are the next steps in this research?

RD: The next step is ongoing; we are researching the impact of travel on sleep. With the Olympic and Paralympic Games in Tokyo this summer, we are studying the impact of eastward travel in particular. The research is ongoing with a lot of athletes who are in camps in preparation for the Games.  We are assessing normal sleep prior to travel, during travel and when they reach their destination.  This study will help us better understand the implications of travel on sleep and enable us to create a robust travel plan for athletes to ensure there performance is affected as little as possible.

To find out more about the work of the Performance Nutrition Team at the Sport Ireland Institute click here