Dietary Information for Gut Endurance Sport Testing (DIGEST): Exploring the relationship between Gut Health, Sports Nutrition Knowledge and Nutritional Practices in Elite Sport
Authors: Kearns Rowan , Dooley James Steven Gerard , Matthews Mark , McNeilly Andrea 
Published: June 2024

Background
Gastrointestinal (GI) complaints are prevalent among athletes and can have a significant impact on performance, particularly in endurance athletes. Possessing greater nutrition knowledge and effectively applying it may play an important role in optimising an athlete’s performance. Despite this, there is a paucity of research regarding GI experiences, sports nutritional knowledge (SNK) and any reciprocal relationship in elite sport. The aim of this study was to design a novel questionnaire to assess the relationship between common GI complaints, GI health, and SNK in elite athletes and coaches in the United Kingdom and Ireland. The study further explored attitudes and practices regarding diet, supplementation, and training practices to gain a comprehensive understanding of potential causative factors to GI distress.
Main Body
This study developed and administered a novel SNK questionnaire, the ‘Dietary Information for Gut Endurance Sport Testing’ (DIGEST) questionnaire to 400 elite athletes and their coaches from various sporting backgrounds. The cross-sectional questionnaire assessed GI complaints, SNK, probiotic usage, dietary practices, and exercise workload. Chi-square analyses and independent sample t-tests were employed to examine associations between variables.
Results
There were 211 reports of GI complaints, with the higher prevalence in individual sports, 161, compared to team sport participants, 50 complaints (p = 0.04). Common GI complaints included stomach pain, bloating, constipation, diarrhoea, bloody diarrhoea, and nausea. The timing of GI complaints challenged conventional understanding with 45.5% of participants experiencing symptoms pre-exercise, 14% at the start of exercise, 35.1% after more than 30 minutes, and 38.7% immediately post exercise. While probiotic use was common (p = 186), its benefits were inconclusive. Bloating and irritable bowel disease (IBD) were significantly correlated with probiotic use, which may indicate individuals with these conditions use probiotics for symptom management. The study found no significant correlation between SNK scores and GI complaints among elite athletes (p = 0.13), suggesting SNK may not play a crucial role in preventing or contributing to these issues. However, it is noteworthy that a substantial number of participants, athletes (mean score of 59%) and coaches (mean score of 58%), demonstrated suboptimal SNK scores below the 65% threshold. Consequently, it remains unclear whether enhancing SNK levels could contribute to the reduction of GI complaints.
Conclusion
The results of this study suggest that both athletes and coaches have sub-optimal SNK, and it appears that SNK is not related to incidence of GI complaints. However, GI complaints remain common in elite sports, especially in individual sports. These complaints occur most frequently before and towards the end of exercise. Future studies should explore exercise intensity, training practices, stress levels, and psychological well-being alongside SNK to better understand GI complaints in this population.