Resting Electrocardiogram and Blood Pressure in Young Athletes and Non-Athletes: A 4-year follow-up

A follow-up data on electrocardiogram (ECG) and blood pressure (BP) changes in adolescent athletes are scarce. We compared ECG and BP between adolescent athletes and non-athletes in a 4-year follow-up. A total of 154 youth sports clubs (SC) in Finland and 100 secondary schools for comparison data participated in this observational follow-up study. Those who maintained or adopted SC participation are referred to as "Always athletes" (n=137), those who never participated in SC as "Never athletes" (n=108) and those who dropped out of SC during the follow-up as "Changers" (n=116). The mean age of the participants was 15.5 (0.6) years in all study groups at baseline. Resting ECG including heart rate, PR interval, QRS duration, QRS axis, QRS amplitude, T axis and QT interval and BP were measured from all participants at baseline and after follow-up. "Always athletes" had lower resting heart rate, more negative T-wave axis and higher QRS amplitude than "Never athletes" at baseline and at 4-years (P < 0.05). "Changers" had lower resting heart rate, more negative T-wave axis and higher QRS amplitude, systolic BP and pulse pressure than "Never athletes" at baseline (P < 0.05). None of the observed differences at baseline, were visible at 4-years (P > 0.05) except the difference in T-wave axis (P = 0.028). The significant group x time interaction between "Changers" and "Never athletes" was found for QRS amplitude (P = 0.017). Adolescent athletes have several training-induced cardiovascular adaptations, which return towards the levels of non-athletes after cessation of regular training. This article is protected by copyright. All rights reserved.

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.