Physical activity volume and cardiac electrical remodelling in amateur university athletes: associations with training intensity

Abstract

Background and Study Aim. Physical training is associated with cardiac electrical adaptations that may be reflected in electrocardiographic (ECG) characteristics. Although physical activity can be quantified in terms of both total volume and intensity, their associations with ECG characteristics in amateur university athletes are of practical interest. The present study examined associations of total and intensity-specific IPAQ-derived physical activity with ECG characteristics in amateur university athletes over the preceding seven days. Materials and Methods. This cross-sectional study examined 149 amateur student-athletes (70 males, 79 females; mean age 20.04 ± 1.47 years) at Hassan 1st University, Morocco. Physical activity was quantified in MET-min/week via the IPAQ-SF, and 12-lead ECGs were interpreted according to the 2017 International Criteria. Participants were stratified into MET-min/week tertiles (T1 ≤ 2,616, n = 50; T2 2,617–4,692, n = 50; T3 > 4,692, n = 49). ECG parameters were compared across tertiles by ANOVA with Tukey's post-hoc correction and trend tests; Pearson correlations quantified activity–ECG associations. Results. No continuous ECG parameter differed significantly across tertiles (ANOVA, all p ≥ .077; Jonckheere–Terpstra, all p ≥ .27). Among categorical findings, only LVH voltage-criteria positivity showed a significant trend (2.0%, 10.0%, 14.3% across T1–T3; Cochran–Armitage p = .030); no other finding was significant (all p ≥ .19). A segmented-regression test for a non-linear threshold in Sokolow-Lyon V5 was not significant (F = 1.49, p = .22), with a wide bootstrap breakpoint 95% CI (1,348–6,207 MET-min/week). VPA showed nominally significant unadjusted correlations with QRS duration (r = .164, p = .045), Sokolow-Lyon V5 (r = .170, p = .038), and Cornell index (r = .184, p = .025), but none survived FDR correction (all q ≥ .29) or adjustment for sex (all p ≥ .42). VPA was a significantly stronger correlate than total volume only for QRS duration (Steiger's Z, p = .008), not for Sokolow-Lyon V5 (p = .32) or Cornell index (p = .067). Conclusions. ECG characteristics classified by the 2017 International Criteria showed little robust association with self-reported physical activity in this exploratory cross-sectional sample once multiplicity and sex confounding were accounted for. The significant trend in LVH voltage criteria and the absence of a supported activity threshold indicate that these results are hypothesis-generating. The present study does not evaluate diagnostic performance; dedicated validation is required before any screening application.