INTRODUCTION:There are substantial evidence for the numerous positive health benefits of physical activity (PA) [1]. At the same time, PA-levels in European and Swedish children are insufficient [2]. Inadequate PA-levels, and associated noncommunicable diseases, are regarded as one of the most significant public health challenges confronting us. Hence, it is important to understand how we can promote ways for children to reach adequate PA-levels. Physical Literacy (PL), a theory with potential benefits for PA-behaviors and health, has garnered increasing attention over the last few years. Encompassing physical, affective, and cognitive dimensions PL is often described as an individual’s capacity, confidence, and motivation to partake- and engage in PA [3]. The early childhood years are suggested for PL promotion since this period is regarded as crucial for PA-behaviors, future health, and the opportunity to reach most children via school settings. However, the assessment and status of PL in young children, specifically in Sweden, is at best scarce. Consequently, research is required to assess PL and its connection to PA-levels in young Swedish children.

METHODS:The data for this study will be derived from hip-worn accelerometers (GT3X+, Actigraph) worn for 7 days to assess PA-levels, as well as a modified version of the Canadian Preschool Physical Literacy Assessment to assess PL. The study will include 412 preschool children, aged 3-6, from 20 preschools. The data will be analyzed and presented via descriptive statistics, and multi-level linear regression models will be used to determine associations between total- and intensity stratified PA-levels and PL.

RESULTS:Tentatively, the results of this study are expected to provide: 1) a picture of PL and PA in Swedish preschool children and the connection therein; 2) much-needed data for the fields of PL and early childhood research; 3) Indications on effectiveness of PL for promoting PA; and 4) guidance for future research in PL.

CONCLUSION:With individual, and public health advancements in mind, there is ample reason to enhance our understanding of the relationship between PL and PA-levels of Swedish preschool children, as well as, adding data to the PL-field. The present study has the potential to contribute to these objectives.

References:1. Warburton, D. E., & Bredin, S. S. (2017). Health benefits of physical activity: a systematic review of current systematic reviews. Current opinion in cardiology, 32(5), 541-556.2. Steene-Johannessen J, Hansen BH, Dalene KE, Kolle E, Northstone K, Møller NC, et al. Variations in accelerometry measured physical activity and sedentary time across Europe – harmonized analyses of 47,497 children and adolescents. Int J Behav Nutr Phys Act. 2020;17(1):38.3. Edwards, L. C., Bryant, A. S., Keegan, R. J., Morgan, K., & Jones, A. M. (2017). Definitions, foundations and associations of physical literacy: a systematic review. Sports medicine, 47(1), 113-126.

Introduction

It is well known that muscle strength increases in both the untrained and trained limb after a period of unilateral strength training. However, it is not known how this so called cross-education effect (CE-effect) is affected by a long period of detraining, and if there are any sex differences. Also, there are conflicting results regarding the effect of unilateral training on muscle mass in the untrained limb.

Aim

The primary objective was to study the CE-effect in men and women after a period of unilateral strength training and detraining. The secondary objective was to study if training one limb would affect the muscle mass of the homologous opposite limb.

Method

Sixteen untrained individuals, 9 females and 7 males, completed the study. The training intervention was 10 weeks (34 sessions) of unilateral strength training (leg press (LP) and leg extension (LE) exercise). 1RM and muscle thickness (vastus lateralis) were measured pre-, post- and 20 weeks post-training.

Results

Strength (1RM) in the trained leg increased for both men and woman (LP: ~60%, LE ~20%, p<0.01), with no sex differences. However, only the men had a strength increase in the untrained leg (LP: 26%, LE: 10%, p<0.05) and the non-significant increase observed for the woman (LP: 10%, LE: 3%) was significantly smaller than the increase in the men (p<0.05). Muscle thickness increased similarly for both men and women (trained leg: ~14%, p<0.01; untrained leg: ~4%, p<0.05). The detraining period did not affect strength, but muscle thickness was reduced close to pre-training values in both men and women.

Conclusion

The results of the present study show that the CE-effect is larger in men than women, and that it is long lasting (at least 20 weeks). Further, strength training of one leg can increase the muscle mass of the homologous opposite leg.