Much of what is known about exercise and digestive function comes from studies on athletes. Physical activity influences gut function depending on exercise type and exercise intensity. Mechanisms to consider range from pressure alterations in the gut resulting from exertion to blood-flow changes, hormonal impacts, and mechanical damage. Exercise shunts blood away from the gastrointestinal tract toward the working muscles. This is mediated by the degree of sympathetic activity elicited. Higher-intensity activity generates much larger effects over lower-intensity activity in this regard. This reduction in blood flow can be substantial. Research has shown splanchnic blood flow is reduced by as much as 80% with exercise greater than 70% of VO2 max (82% of maximum heart rate), which is at the upper end of aerobic exercise.¹ This represents a significant challenge to the digestive tract and has been shown to lead to increased gut permeability (i.e., leaky gut), disrupt GI microflora, and generate intraluminal endotoxins.² Obviously, these are consequences that any practitioner would want to avoid and is usually working to correct. These responses are aggravated further with dehydration, exercising in hot conditions, and concomitant use of NSAIDs.³ This is an important consideration since many “health-conscious” patients seeking help for digestive distress often engage in strenuous exercise patterns that may be detrimental or contraindicated while undergoing treatment. (more…)