NTproBNP, Lactate, and Hemodynamic Responses to Multiple vs One-Repetition Max Strength Tests

Abstract

Background: Cardiac stress biomarker N-Terminal pro-brain natriuretic peptide (NTproBNP), blood lactate, and hemodynamic responses were compared between one-repetition max (1RM) and multiple-repetition max (MRM) strength assessments in overweight and obese conditions. Methods: Twenty sedentary males, ages 19–28 years, were divided into overweight (n = 11) and obese (n = 9) groups. Subjects performed MRM and 1RM using a chest press machine. Heart rate (HR), blood pressure, blood lactate, and NTproBNP were measured at baseline, immediately post, and 15-min post strength assessment. Power output was also calculated. Results: Significant increases in all variables except NTproBNP were observed from baseline to immediate post (p < 0.05) in both 1RM and MRM. Significant differences in HR were found between 1RM and MRM immediate post (1RM = 122 bpm, MRM = 147 bpm; p = 0.001), and blood lactate immediate post (1RM = 3.0 mmol·L−1, MRM = 5.7 mmol·L−1; p = 0.001) and 15-min post (1RM = 1.9 mmol·L−1, MRM = 4.mmol·L−1; p = 0.001). BMI interactions were found with systolic blood pressure for 1RM (p = 0.014) and MRM (p = 0.015), and diastolic blood pressure for 1RM (p = 0.047) and MRM (p = 0.006), where obese individuals had higher blood pressure responses compared to overweight. Power output was greater in 1RM vs MRM and greater in the obese compared to overweight. Conclusion: NTproBNP remained at safe levels for MRM and 1RM tests in both groups. Findings suggest MRM may induce greater hemodynamic and metabolic stress compared to 1RM, and obesity may provoke greater blood pressure responses to maximal resistance exercise.