Association between energy balance and metabolic hormone suppression during ultraendurance exercise

Bjoern Geesmann, Jenna C. Gibbs, Joachim Mester, Karsten Koehler

Research output: Contribution to journalArticlepeer-review

32 Scopus citations

Abstract

Ultraendurance athletes often accumulate an energy deficit when engaging in ultraendurance exercise, and on completion of the exercise, they exhibit endocrine changes that are reminiscent of starvation. However, it remains unclear whether these endocrine changes are a result of the exercise per se or secondary to the energy deficit and, more important, whether these changes can be attenuated by increased dietary intake. The goal of the study was to assess the relationship between changes in key metabolic hormones after ultraendurance exercise and measures of energy balance. Metabolic hormones, as well as energy intake and expenditure, were assessed in 14 well-trained male cyclists who completed a 1230-km ultraendurance cycling event. After completion of the event, serum testosterone (–67% ± 18%), insulin-like growth factor-1 (IGF-1) (–45% ± 8%), and leptin (–79% ± 9%) were significantly suppressed (P < .001) and remained suppressed after a 12-h recovery period (P < .001). Changes in IGF-1 were positively correlated with energy balance over the course of the event (r = .65, P = .037), which ranged from an 11,859-kcal deficit to a 3593-kcal surplus. The marked suppression of testosterone, IGF-1, and leptin after ultraendurance exercise is comparable to changes occurring during acute starvation. The suppression of IGF-1, but not that of other metabolic hormones, was strongly associated with the magnitude of the energy deficit, indicating that athletes who attained a greater energy deficit exhibited a more pronounced drop in IGF-1. Future studies are needed to determine whether increased dietary intake can attenuate the endocrine response to ultraendurance exercise.

Original languageEnglish
Pages (from-to)984-989
Number of pages6
JournalInternational Journal of Sports Physiology and Performance
Volume12
Issue number7
DOIs
StatePublished - Aug 2017
Externally publishedYes

Keywords

  • Energy deficit
  • IGF-1
  • Insulin-like growth factor-1
  • Leptin
  • Testosterone

Fingerprint

Dive into the research topics of 'Association between energy balance and metabolic hormone suppression during ultraendurance exercise'. Together they form a unique fingerprint.

Cite this