The effects of warm weather on children's outdoor heat stress and physical activity in a preschool yard in Gothenburg, Sweden.

Hot weather conditions can have negative impacts on the thermal comfort and physical activity of vulnerable groups such as children. The aim of this study is to analyze the effects of warm weather on 5-year-old children's thermal comfort and physical activity in a preschool yard in Gothenburg, Sweden. In situ measurements were conducted for 1-1.5 h in the early afternoon on 8 days in May, June, and August of 2022. The thermal comfort and physical activity was estimated with GPS-tracks, heart rate monitors, and step counts and compared to observed weather conditions. Results show that physical activity decreases under warmer weather conditions, depicted by a decrease in distance moved, step counts, and highest registered pulse. Moreover, on warm days, the children avoid sunlit areas. For 50% or more of the time spent in sunlit areas, the children are exposed to cautious levels of heat. In shaded areas, on the other hand, the children are less exposed, with five out of 8 days having 50% or more of the time at neutral levels. The study demonstrates the importance of access to shaded areas in preschool yards where children can continue their active play while simultaneously maintaining a safe thermal status.

Effectiveness of an 18-week general strength and foam-rolling intervention on running-related injuries in recreational runners.

RATIONALE: More research is needed to uncover the effectiveness of combined strength and foam-rolling interventions to prevent running-related injuries. OBJECTIVES: To evaluate effectiveness of an 18-week general strength and foam-rolling intervention on the incidence of running-related injuries. METHOD: This is an 18-week observational comparative study. A total of 433 recreational runners participated (n = 203 female). The intervention group (n = 228) performed general strength and foam-rolling exercises twice weekly for 18 weeks, the control group (n = 205) maintained their regular training habits. Running volume and running-related pain were reported weekly. Secondary analyses were performed on the subgroups of the intervention group based on compliance; low compliance (n = 100), intermediate compliance (n = 63), and high compliance (n = 65). Cumulative incidence proportions were calculated and time-to-event statistics were performed to compare survival times between groups. Univariate cox proportional hazards ratio was calculated to estimate the risk of running-related injuries at 18 weeks. RESULTS: A total of 100 running-related injuries were sustained. The cumulative incidence proportion for the control and intervention groups was 27.1% (95% CI: 21.4-33.9) and 23.0% (95% CI: 17.8-29.4), respectively. No statistically significant difference was found between the overall intervention group and control group (log-rank p = 0.31). A significant difference existed between the high-compliance subgroup and the control group (log-rank p = 0.00). Highly compliant runners were 85% less likely (hazard rate ratio = 0.15; 95% CI: 0.05-0.46) to sustain an injury during the study compared with controls. CONCLUSION: Recreational runners highly compliant with the intervention were 85% less likely and took on average 57 days longer to sustain a running-related injury when compared with controls, with a cumulative incidence proportion of 4.6% after 18 weeks.

Recreational Runners With a History of Injury Are Twice as Likely to Sustain a Running-Related Injury as Runners With No History of Injury: A 1-Year Prospective Cohort Study.

OBJECTIVES: To investigate (1) the cumulative incidence proportion and the most common anatomical locations of running-related injuries in recreational runners, and (2) the associations between running-related injuries and previous injury, running experience, weekly running distance, age, sex, and body mass index. DESIGN: A 1-year prospective cohort study. METHODS: Two hundred twenty-four recreational runners (average weekly running distance for the past 12 months, 15 km) were included (89 women, 135 men). Pain information was reported weekly for 1 year, and all running-related injuries that resulted in time loss or medical consultation were recorded. We accounted for censoring when calculating cumulative incidence proportion, and used crude Cox proportional hazards regression to evaluate whether the variables of interest were associated with running-related injuries. RESULTS: The 1-year cumulative incidence proportion of running-related injuries was 45.9% (95% confidence interval [CI]: 38.4%, 54.2%). The most common anatomical locations were the knee (20/75, 27%) and Achilles tendon/calf (19/75, 25%). Previous injury was associated with a higher injury rate (hazard rate ratio = 1.9; 95% CI: 1.2, 3.2), while the other variables had no statistically significant association with injury. CONCLUSION: There were 75 running-related injuries during the 1-year surveillance period, for a cumulative incidence proportion of 46%. The most common injuries were to the knee and Achilles tendon/calf. Recreational runners with a previous injury were twice as likely to sustain a running-related injury as runners with no previous injury. J Orthop Sports Phys Ther 2021;51(3):144-150. Epub 25 Dec 2020. doi:10.2519/jospt.2021.9673.

Associations between biomechanical and clinical/anthropometrical factors and running-related injuries among recreational runners: a 52-week prospective cohort study.

BACKGROUND: The purpose of this exploratory study was to investigate whether runners with certain biomechanical or clinical/anthropometrical characteristics sustain more running-related injuries than runners with other biomechanical or clinical/anthropometrical characteristics. METHODS: The study was designed as a prospective cohort with 52-weeks follow-up. A total of 224 injury-free, recreational runners were recruited from the Gothenburg Half Marathon and tested at baseline. The primary exposure variables were biomechanical and clinical/anthropometrical measures, including strength, lower extremity kinematics, joint range of motion, muscle flexibility, and trigger points. The primary outcome measure was any running-related injury diagnosed by a medical practitioner. Cumulative risk difference was used as measure of association. A shared frailty approach was used with legs as the unit of interest. A total of 448 legs were included in the analyses. RESULTS: The cumulative injury incidence proportion for legs was 29.0% (95%CI = 24.0%; 34.8%). A few biomechanical and clinical/anthropometrical factors influence the number of running-related injuries sustained in recreational runners. Runners with a late timing of maximal eversion sustained 20.7% (95%CI = 1.3; 40.0) more injuries, and runners with weak abductors in relation to adductors sustained 17.3% (95%CI = 0.8; 33.7) more injuries, compared with the corresponding reference group. CONCLUSIONS: More injuries are likely to occur in runners with late timing of maximal eversion or weak hip abductors in relation to hip adductors.

Study protocol of a 52-week Prospective Running INjury study in Gothenburg (SPRING).

INTRODUCTION: It is assumed that a running-related (overuse) injury occurs when a specific structure of the human body is exposed to a load that exceeds that structures' load capacity. Therefore, monitoring training load is an important key to understanding the development of a running-related injury. Additionally, other distribution, magnitude and capacity-related factors should be considered when aiming to understand the causal chain of injury development. This paper presents a study protocol for a prospective cohort study that aims to add comprehensive information on the aetiology of running-related injuries and present a new approach for investigating changes in training load with regard to running-related injuries. METHODS AND ANALYSIS: This study focused on recreational runners, that is, runners exposed to a minimum weekly average of 15 km for at least 1 year. Participants will undergo baseline tests consisting of a clinical/anthropometrical examination and biomechanical measurements. Furthermore, participants will log all training sessions in a diary on a weekly basis for 1 year. The primary exposure variable is changes in training load. A medical practitioner will examine runners suffering from running-related pain and, if possible, make a clear diagnosis. Finally, additional time-varying exposure variables will be included in the main analysis, whereas the analysis for the secondary purpose is based on time-fixed baseline-related risk factors. ETHICS AND DISSEMINATION: Ethical approval (DNR: 712-15) for the study and its design was obtained from the Gothenburg regional ethical review board. The results of the study will be published in peer-reviewed journals.