Resting Electrocardiogram and Blood Pressure in Young Endurance and Nonendurance Athletes and Nonathletes.

CONTEXT: Much information is available on electrocardiogram (ECG) and blood pressure (BP) changes in senior athletes. However, corresponding data on adolescent athletes are scarce. OBJECTIVE: To study the differences in resting ECG and BP values among adolescent endurance athletes, nonendurance athletes, and nonathletes. DESIGN: Cross-sectional study. SETTING: A total of 154 youth sports clubs in Finland and 100 secondary schools for comparison data. PATIENTS OR OTHER PARTICIPANTS: We recruited young athletes (n = 410) aged 14 to 16 years in 10 popular sport disciplines, including winter and summer as well as team and individual sports, and categorized them as endurance or nonendurance sports. Comparison data for age-matched, non-sports club participants (n = 164) were collected via secondary schools. MAIN OUTCOME MEASURE(S): Resting ECG, including heart rate, PR interval, QRS duration, QRS axis, QRS amplitude, T axis, and QT interval as well as systolic and diastolic BPs. RESULTS: No differences in any ECG variable of interest were found between the endurance and nonendurance athletes. The PR interval was longer in endurance athletes than in nonathletes (P = .05). The QRS amplitude (P = .03) was higher among nonendurance athletes than among nonathletes. Diastolic BP was lower among endurance (P = .002) and nonendurance (P = .02) athletes than among nonathletes. Endurance athletes (odds ratio [OR] = 2.85; 95% CI = 1.81, 4.50) and nonendurance athletes (OR = 2.19; 95% CI = 1.43, 3.35) were more likely to have sinus bradycardia than were nonathletes. Nonendurance athletes were more likely to have elevated systolic BP than were endurance athletes (OR = 1.70; 95% CI = 1.07, 2.72) and nonathletes (OR = 1.73; 95% CI = 1.04, 2.87). CONCLUSIONS: Young athletes had similar ECG and BP findings independent of their sports. Physiological adaptations including sinus bradycardia, higher QRS amplitude, and lower diastolic BP, which are commonly seen in adult athletes, were also present in adolescent athletes.

Haemoglobin, iron status and lung function of adolescents participating in organised sports in the Finnish Health Promoting Sports Club Study.

OBJECTIVES: To compare laboratory test results and lung function of adolescent organised sports participants (SP) with non-participants (NP). METHODS: In this cross-sectional study, laboratory tests (haemoglobin, iron status), and flow-volume spirometry were performed on SP youths (199 boys, 203 girls) and their NP peers (62 boys, 114 girls) aged 14-17. RESULTS: Haemoglobin concentration <120/130 g/L was found in 5.8% of SP and 5.1% NP (OR 1.20, 95% CI 0.54 to 2.68). Ferritin concentration below 15 µg/L was found in 22.7% of both SP and NP girls. Among boys ferritin <30 µg/L was found in 26.5% of SP and 30.2% of NP (OR 0.76, 95% CI 0.40 to 1.47). Among SP iron supplement use was reported by 3.5% of girls and 1.5% of boys. In flow-volume spirometry with bronchodilation test, 7.0% of SP and 6.4% of NP had asthma-like findings (OR 1.17, 95% CI 0.54 to 2.54); those using asthma medication, that is, 9.8% of SP and 5.2% of NP were excluded from the analysis. CONCLUSIONS: Screening for iron deficiency is recommended for symptomatic persons and persons engaging in sports. Lung function testing is recommended for symptomatic persons and persons participating in sports in which asthma is more prevalent.