Article human 26 Humans 22 female 15 male 15 adult 13 controlled study 11 physical activity 10 machine learning 6 mathematical model 6 middle aged 6 aged 5 algorithm 5 human experiment 5 major clinical study 5 normal human 5 questionnaire 5 signal noise ratio 5 Adult 4 Male 4 Walking 4 clinical article 4 comparative study 4 electroencephalography 4 exercise 4 heart rate 4 nonhuman 4 outcome assessment 4 pilot study 4 procedures 4