Could exercise put your gut in distress?

Published on 1^st January 2017

Gastrointestinal (GI) distress is a common but rarely talked about problem that is experienced by athletes at all levels.¹ In fact, studies have shown that it affects between 30 and 65 per cent of runners, with the most frequent symptoms including cramping, bloating and loose bowel movements.² Most people simply try to put up with it.

It’s thought that there are three main causes of GI problems:

• Physiological (caused by reduced blood flow to the gut during exercise)
• Mechanical (bouncing effect of running, for example)
• Nutritional (such as excess intake of carbohydrate drinks)

Other contributors include alcohol consumption, anti-inflammatory medications, emotional stress, pathogenic bacteria, and excess pressure on the abdominal wall.³

Ultimately, these symptoms can impair performance and possibly prevent athletes from winning or even finishing a race. However, many nutritional steps can be taken to support the problem. These include:

• Manipulating the fibre content of the diet during training
• Adding in probiotics (‘friendly’ bacteria)
• Using drinks containing multiple transportable carbohydrates⁴ (glucose plus fructose) as fuel during a race

References

1. de Oliviera E and Burini R (2014). Carbohydrate-dependent, exercise-induced gastrointestinal distress. Nutrients; 6:4191-4199.
2. Simons S and Kennedy R (2004). Gastrointestinal problems in runners. Current Sports Medicine Reports. DOI: 10.1249/00149619-200404000-00011.
3. Casey E, Mistry D and Macknight J (2005). Training room management of medical conditions: Sports gastroenterology. Clinics in Sports Med; 24:4191-4199.
4. Jeukendrup A (2010). Carbohydrate and exercise performance: the role of multiple transportable carbohydrates. Current Opinion in Clinical Nutrition and Metabolic Care; 4:452-457.