Figure 1.

Subject characterization and experimental design

Subjects (winter swimmers [WS], n = 7; controls [C], n = 8) performed an oral glucose tolerance test (OGTT). n represents the number of human individuals in each group and is consistent throughout this figure unless otherwise stated.

(A) Plasma glucose levels before (time point 0) and following glucose ingestion.

(B) Plasma glucose levels 2 h after glucose ingestion.

(C) Plasma insulin levels before (time point 0) and following glucose ingestion.

(D) Pulse before and during cooling and after reheating.

(E) Systolic blood pressure in response to cooling during a cold pressor test.

(F) Diastolic blood pressure in response to cooling.

(G) Experimental design depicting the measurements performed during the three experimental days.

Data are presented as mean ± SD. Differences were assessed using two-way repeated-measures ANOVA with Sidak’s multiple comparison tests to assess specific differences except in (B), where an unpaired t test was used. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.