Variations in leptin and insulin levels within one swimming season in non-obese female cold water swimmers

Scand J Clin Lab Invest. 2016 Oct;76(6):486-91. doi: 10.1080/00365513.2016.1201851. Epub 2016 Jul 4.


Aim: We examined whether cold water swimming for seven consecutive months changes basal leptin and insulin concentrations and insulin sensitivity in healthy non-obese women.

Materials and methods: Fourteen recreational female swimmers aged 45 ± 8.7 years, regularly swimming outdoors during winter months were exposed to cold water at least twice a week. Fasting blood samples were collected in October, January and April. Serum leptin, insulin and glucose concentrations were tested and insulin sensitivity was calculated using updated model HOMA2.

Results: Repeated cold water baths significantly increased insulin sensitivity and decreased insulin and leptin concentrations (p = 0.006, p = 0.032, p = 0.042, respectively). Leptin concentration positively correlated with body-mass index (BMI) and insulin level (r = 0.412, r = 0.868, respectively). Insulin level inversely correlated with insulin sensitivity and positively with glucose (r = -0.893, r = 0.166, respectively). No associations between leptin and insulin sensitivity were found.

Conclusion: Regular cold water swimming may stimulate metabolic changes suggesting that leptin and insulin participate in adaptive metabolic mechanisms triggered by repeated cold exposure accompanied by mild exercise in healthy non-obese women.

Keywords: Cold water swimming; insulin; insulin sensitivity; leptin.

MeSH terms

  • Adult
  • Biomarkers / blood
  • Blood Glucose
  • Body Mass Index
  • Cold Temperature
  • Female
  • Humans
  • Insulin / blood*
  • Insulin Resistance
  • Leptin / blood*
  • Middle Aged
  • Obesity / blood
  • Seasons
  • Swimming


  • Biomarkers
  • Blood Glucose
  • Insulin
  • Leptin