## 2 Materials and Methods
The information registered in those diaries was coded by the time engaged in those activities multiplied by the estimated MET (metabolic equivalent task) values according to the compendium energy expenditure [48]. Those activities were included in the daily PA on the corresponding day, replacing the hours in which it was assumed that the device was unworn, and then added for the valid days [49]. The PA intensity level was recorded according to moderate, vigorous or very vigorous intensity PA, as proposed by [PERSON] [50]. The time encompassed by moderate and vigorous PA (MVPA) was determined [50]. The mean times per day at the different intensities were determined by summing all the minutes spent in the count criteria and dividing them by the valid days. The defined cut-points proposed by the [PERSON] equation [50] were 500-3999 counts for moderate intensity, 4000-7599 counts for vigorous intensity and 7600 or more counts for very vigorous intensity. The maturity measures consisted of determining the maturity offset during adolescence and the time before or after the PHV according to [PERSON] [51], and of calculating the bone age using radiographs of the left hand and wrist according to the Tanner-Whitehouse III (TW3) method [52]. X-rays were performed in a single session, and the ossification of thirteen bones was evaluated. Maturity was rated by one trained examiner without knowledge of the chronological ages of the participants. The maturity evaluation was independently replicated two weeks later by the same observer, and the intra-observer technical error of measurement (TEM) was determined. An expert observer evaluated a random subsample of 37 radiographies, and the inter-observer TEM was determined. The intra-observer TEM was 0.03 (\(\pm\)0.004) years, and the inter-observer TEM was 0.03 (\(\pm\)0.99) years. Three bone maturity groups were considered for descriptive data: late mattervers, in which the bone age was lower than the decimal age by more than one year; normal matuvers, in which the difference between the bone and decimal ages was no more than one year; and early matuvers, in which the bone age was more than one year higher than the decimal age (0 = \"late\"; 1 = \"on time\"; 2 = \"early\") [53; 54]. The maturity offset was predicted using a specific equation for each sex (the standard error of the estimates was 0.592 for boys and 0.569 for girls) based on Canadian and Belgian samples [51]. This equation can be used to classify adolescents as pre- or post-PHV and can also be used to group the individuals according to years before or after PHV. The chronological age minus the maturity offset provides an estimate of the age of PHV. The method appears to be useful during the period of growth acceleration [55]. Three maturity offset groups were also defined: pre-PHV (0 = \"\(<\)\(-\)0.5 years of PHV\"), on PHV (1 = \"[\(-\)0.5, 0.5] years of PHV\") and post-PHV (2 = \"\(>\)0.5 years of PHV\"). Chronological age was defined as a whole year at the midpoint of a range (e.g., the \"12-year-old\" CA group of youth had chronological ages between 11.50 and 12.49). In order to perform descriptive analysis, four age groups were defined. The age groups had an interval of two years (0 = \"9.5-11.49 years\", 1 = \"11.5-13.49 years\", 2 = \"13.50-15.49 years\", and 3 = \"\(\geq\)15.50 years\"). Data analysis  
The statistical analysis was conducted using SPSS 22.0 software (SPSS Inc., Chicago, IL, USA), and a significance level of 5% was considered. Descriptive statistics were used to determine the sample characteristics. The variable selection started with a bivariate analysis of the dependent variables and each predictor. The dependent variables were injury occurrence (0 = \"no\"; 1 = \"yes\"), injury rate (number of sports injuries per 1000 h of exposure), injury type (0 = \"strain\"; 1 = \"sprain\"; 2 = \"fracture\") and body area injury location (0 = \"lower limbs\"; 1 = \"upper limbs\").