High-intensity interval exercise test stimulates growth hormone secretion in children

Abstract Background exercise stimulates growth hormone (GH) secretion and may serve as a promising physiological test for the diagnosis of GH deficiency. However, exercise standardization for a feasible GH test is still lacking. The aim of the present study was to examine the GH secretion to high intensity interval exercise. Methods Seventeen children (12.4 ± 2.6 years) with impaired growth rate performed high-intensity interval exercise test (HIIE) that included 10 intervals of 15 s all out pedaling against resistance determined by age, sex and weight on a cycle ergometer with 1-min active rest between each interval. Power output measurements were collected during the test. Blood samples were collected before, immediately after, 30, 45, and 60 min after the beginning of the exercise test. GH response was compered to pharmacological provocation test (clonidine or glucagon). Results HIIE led to a significant increase in GH levels (p   10 watts/kg had normal GH secretion. Conclusions HIIE is a brief and individualized exercise protocol that may be used as a physiological provocation test for GH secretion. There might be a minimum of anaerobic power needed to induce adequate GH response during HIIE.