Effects of 4-Week Low-Load Resistance Training with Blood Flow Restriction on Muscle Strength and Left Ventricular Function in Young Swimmers: A Pilot Randomized Trial

Low-load resistance training combined with blood flow restriction (BFR) is known to result in muscle hypertrophy and strength similar that observed higher loads. However, the effects of BFR on cardiac structure function remain largely unknown. Therefore, purpose this randomized study was compare conventional high-load (HL-RT) low-load (LL-BFR) left ventricular function. Sixteen young swimmers (mean ± standard deviation: age = 19.7 1.6 years, body mass 78.9 9.7 kg, height 180.8 5.8 cm) were randomly allocated a HL-RT group (n 8) or LL-BFR pressure band (200 mmHg) placed both thighs participants for 4 weeks (3 days·week-1). Outcome measures taken at baseline after training, included composition, one-repetition maximum (1RM) back squat, echocardiography measures. The 1RM squat significantly improved (partial eta squared (Ƞ2) 0.365; p 0.013) difference (Δ) 6.6 kg; [95% confidence interval (CI) −7.09 20.27]) groups (Δ 14.7 CI 3.39 26.10]), no main effect × time interaction (p > 0.05). Interventricular septum end-systolic thickness showed slight but statistically significant increase (Ƞ2 0.253; 0.047), yet there There changes 0.05) other parameters (e.g., (LV) mass, LV output, ejection fraction, stroke volume) programs. Results suggest improve similarly limited swimmers.