Humans human 6 mobile application Article 5 machine learning 5 algorithm 3 Mobile Applications 2 adult 2 biological marker 2 controlled study 2 education 2 fatigue 2 female 2 learning algorithm 2 major clinical study 2 male 2 middle aged 2 prediction 2 sensitivity and specificity 2 walking 2 Access to Information 1 Activities of Daily Living 1 Activity recognition 1 Adaptive sampling 1 Adolescent 1 Adult 1 Age Factors 1 Age-matched controls 1 Aged 1 Algorithmic framework 1