The Effect of Physical Activity on Heart Structure and Function in African University Students: A Comparative Cross-Sectional Study

Background: Regular physical activity induces physiological cardiac remodeling (“athlete’s heart”), which may overlap with pathological hypertrophy. Regional echocardiographic and electrocardiographic data among young African adults are limited. This study evaluated how graded physical activity relates to cardiac structure and function among university students in Ghana. Methods: In this comparative cross-sectional study, 174 apparently healthy students aged 18–30 years were categorized into four physical activity groups in the preceding six months: level 1, no regular exercise (n = 29, 16.7%); level 2, <30 min/day of exercise (n = 41, 23.6%); level 3, 30 to 60 min/day of moderate exercise (n = 29, 16.7%); and level 4, >1 h/day of vigorous exercise (n = 75, 43.1%). Anthropometry, blood pressure, 12-lead electrocardiography, and comprehensive transthoracic echocardiography were obtained. Cardiac indices were compared across activity levels using the Kruskal–Wallis or Welch’s ANOVA test, with post hoc comparisons and regression analyses performed where appropriate. Results: Participants were predominantly male (56.3%), with a mean age of 22.3 ± 3.50 years, BMI of 23.0 ± 4.39 kg/m2, systolic blood pressure of 118 ± 13.0 mmHg, diastolic blood pressure of 71.3 ± 9.11 mmHg, and heart rate of 66.9 ± 10.9 bpm. Compared with sedentary participants, those in level 4 had a higher IVSd (9.87 ± 1.61 vs. 8.17 ± 1.47 mm, p < 0.001), LVIDd (43.6 ± 6.96 vs. 40.2 ± 3.58 mm, p = 0.002), LVPWd (10.1 ± 1.95 vs. 8.91 ± 1.60 mm, p = 0.003), and LVM (54.6 ± 7.45 vs. 47.1 ± 6.57 g, p < 0.001). EDV and ESV also increased with activity (90.1 ± 24.8 vs. 69.7 ± 17.8 mL, p < 0.001; 32.4 ± 12.8 vs. 25.6 ± 6.52 mL, p = 0.023). Systolic function was preserved across groups, with an EF of 59.3 ± 4.86% in level 4 vs. 58.3 ± 5.34% in level 1 (p = 0.707). Level 4 participants had a higher SV (57.6 ± 16.7 vs. 46.3 ± 10.4 mL, p = 0.003), CO (3.83 ± 1.17 vs. 3.05 ± 0.70 L/min, p = 0.022), and CI (2.19 ± 0.66 vs. 1.77 ± 0.37 L/min/m2, p = 0.015). Bradycardia was most frequent in level 4 (35.8% vs. 18.2% in level 1, p = 0.041), and PR interval was longer in participants exercising ≥30 min/day than in those exercising <30 min/day (166 ± 23.2 vs. 162 ± 21.8 ms, p = 0.031). Conclusions: In young African university students, greater physical activity was associated with mild physiological remodeling, including a higher left ventricular wall thickness, cavity size, and mass, while systolic and diastolic indices remained preserved. The mean values in the most active group were 9.87 mm IVSd and 10.1 mm LVPWd with preserved EF, supporting activity-related adaptation rather than overt pathological hypertrophy and highlighting the need for population-specific cardiovascular interpretation.