A longitudinal study on the effect of bicycle commuting on body composition, metabolic, and cardiovascular health

Abstract

The physiological health benefits of bicycle commuting is well-documented. This novel study elucidates the effects of bicycle commuting at the vascular level by employing the gold standard measure for arterial stiffness. Objective: To monitor changes in body composition, metabolic, and cardiovascular health markers in adult bicycle commuters. Methods: This longitudinal study examines the health of bicycle commuters (n = 17, 7 males, age: 48.9 ± 10.9yr.; weight: 84.0 ± 19.7kg; height: 1.7 ± 0.1m) with measurements taken over a year (1: baseline; 2: 3-5 months; 3: 7 – 10 months; 4: 12 – 14 months). Measurements include pulse wave velocity (PWV), body mass index (BMI), waist : hip ratio (WHR), cholesterol ratio, blood glucose level, glycated haemoglobin (HbA1c), systolic (SBP) and diastolic blood pressure (DBP), and resting heart rate (RHR). A repeated-measures analysis of variance is used to generate the following results: time comparison: mean change, ±90% confidence interval, and a qualitative interpretation. Results: Compared to baseline, BMI and SBP improved between measurement points 1 and 4 (BMI 1v4: -2.5, ±3.4 kg.m2; likely beneficial; SBP 1v4: -10.0, ±10.0 mmHg; likely beneficial), while DBP steadily improved at all time points (DBP: 1v2: -2.9, ±5.3; unclear; 1v3 -5.5, ±5.6, likely beneficial; -8.9, ±5.9 mmHg; very likely beneficial). RHR and PWV maintained likely beneficial improvements at all time points (RHR: 1v2: -4.9 ±4.5; 1v3: -4.6, ±4.5; 1v4: -4.3, ±4.8 b.min-1; PWV: 1v2: -0.9, ±0.88; 1v3: -0.89, ±0.94; 1v4: -1.1, ±0.97 m.s-1). There were possibly harmful changes in HbA1c, glucose and cholesterol at all time points (HbA1c: 1v2: -0.21, ±0.3; 1v3: 0.34, ±0.31; 1v4: 0.09, ±0.34%; blood glucose level: 1v2: 4.7, ±11; 1v3: 3.4, ±12; 1v4: 4.7, ±12 mg.dL-1; cholesterol ratio: 1v2: 0.3, ±0.56; 1v3: 0.41, ±0.6; 1v4: 0.23, ±0.62). Conclusions: Habitual bicycle commuting has a beneficial effect at the vascular level and may be suitable in the prevention of atherosclerotic-derived cardiovascular disease. Conversely, metabolic health tended to decline over the course of the year. It is possible that bicycle commuting led to compensatory behaviour changes in nutrition and/or a reduction in other physical activities. Nutritional support and physical activity education may improve outcomes for adult bicycle commuters.