VOLUME 14 | Proc4 | 2019 | S1169 Supplementary Issue: Spring Conferences of Sports Science. International Seminar of Physical Education, Leisure and Health, 17-19 June 2019. Castelo Branco, Portugal Proceedings of the International Seminar of Physical Education, Leisure and Health, 17-19 June 2019. Castelo Branco, Portugal Table of Contents Muscle soreness and fatigue and their associations with internal and external load measures in professional soccer players .......................................................................................................................1181 Internal and external training load associations in professional soccer players ..............................1185 Comparison of motivational factors for the practice of exercise at gyms and nature and adventure sports .............................................................................................................................................................1189 Association of physical activity, self-concept and self-efficacy in high school students................1193 Effect of the Internet and online social media on awareness of ACSM physical activity recommendations ........................................................................................................................................1197 Physical activity level and perceptions about exercise in patients with Osteoporosis ....................1201 Parental perceptions of physical activity benefits for children with autism spectrum disorders ...1205 Relationship of intrinsic motivation towards sport, with variables related to a healthy lifestyle....1209 Differences between gender and population groups, motivational variables and healthy lifestyles ........................................................................................................................................................................1213 Short-term effects of myofascial release on isometric knee extensors strength ..............................1217 Iron, phosphorus and magnesium erythrocyte concentrations in men with a high, moderate or low level of physical training .............................................................................................................................1221 Possible relationship between some trace metals and the hormone insulin in high-level athletes ........................................................................................................................................................................1225 Erythrocyte concentrations of chromium, manganese and zinc in men with a high, moderate or low level of physical training .............................................................................................................................1228 Proceeding Cite this article as: Proceedings of the International Seminar of Physical Education, Leisure and Health; Castelo Branco, Portugal. (2019). Journal of Human Sport and Exercise, 14(4proc), S1169-S1823. doi:https://doi.org/10.14198/jhse.2019.14.Proc4.82