Open AccessValidity and reliability of a field technique for sweat Na + and K + analysis during exercise in a hot‐humid environment
Author(s) -
Baker Lindsay B.,
Ungaro Corey T.,
Barnes Kelly A.,
Nuccio Ryan P.,
Reimel Adam J.,
Stofan John R.
Publication year - 2014
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.12007
Subject(s) - centrifuge , syringe , high performance liquid chromatography , chromatography , chemistry , sweat , medicine , physics , psychiatry , nuclear physics
This study compared a field versus reference laboratory technique for extracting (syringe vs. centrifuge) and analyzing sweat [Na + ] and [K + ] (compact Horiba B‐722 and B‐731, HORIBA vs. ion chromatography, HPLC) collected with regional absorbent patches during exercise in a hot‐humid environment. Sweat samples were collected from seven anatomical sites on 30 athletes during 1‐h cycling in a heat chamber (33°C, 67% rh). Ten minutes into exercise, skin was cleaned/dried and two sweat patches were applied per anatomical site. After removal, one patch per site was centrifuged and sweat was analyzed with HORIBA in the heat chamber (CENTRIFUGE HORIBA) versus HPLC (CENTRIFUGE HPLC). Sweat from the second patch per site was extracted using a 5‐ mL syringe and analyzed with HORIBA in the heat chamber (SYRINGE HORIBA) versus HPLC (SYRINGE HPLC). CENTRIFUGE HORIBA, SYRINGE HPLC, and SYRINGE HORIBA were highly related to CENTRIFUGE HPLC ([Na + ]: ICC = 0.96, 0.94, and 0.93, respectively; [K + ]: ICC = 0.87, 0.92, and 0.84, respectively), while mean differences from CENTRIFUGE HPLC were small but usually significant ([Na + ]: 4.7 ± 7.9 mE ql/L, −2.5 ± 9.3 mE q/L, 4.0 ± 10.9 mE q/L (all P < 0.001), respectively; [K + ]: 0.44 ± 0.52 mE q/L ( P < 0.001), 0.01 ± 0.49 mE q/L ( P = 0.77), 0.50 ± 0.48 mE q/L ( P < 0.001), respectively). On the basis of typical error of the measurement results, sweat [Na + ] and [K + ] obtained with SYRINGE HORIBA falls within ±15.4 mE q/L and ±0.68 mE q/L, respectively, of CENTRIFUGE HPLC 95% of the time. The field (SYRINGE HORIBA) method of extracting and analyzing sweat from regional absorbent patches may be useful in obtaining sweat [Na + ] when rapid estimates in a hot‐humid field setting are needed.