Monitoring National Center for Biotechnology Information NCBI NLM MEDLINE humans pubmed abstract nih national institutes of health national library of medicine reproducibility of results research support non-u.s. gov't u.s. gov't non-p.h.s. adult female male N.I.H. Extramural young adult physiologic / instrumentation* physiologic / methods* healthy volunteers calibration pmid:26819044 pmc4996079 doi:10.1038/nature16521 clinical study wei gao sam emaminejad ali javey bicycling / physiology body water electrolytes / analysis glucose / analysis lactic acid / analysis precision medicine / instrumentation precision medicine / methods running / physiology skin skin temperature sweat / chemistry*