The Impact Of Anterior Cruciate Ligament Reconstruction On Cardiorespiratory Fitness And Body Composition

Body composition and cardiorespiratory fitness (CRF) are indicators of cardiovascular (CV) health. Limited previous evidence suggests that individuals with anterior cruciate ligament reconstruction (ACLR) have poorer indicators of CV health such as reduced physical activity participation and higher body fat (%BF) when compared to uninjured peers (CON). However, it is unclear how these factors may impact CRF. PURPOSE: The purpose of this ongoing study was to compare CRF (VO2peak), body mass index (BMI), and body fatness (%BF and fat mass) between individuals with ACLR and uninjured controls. METHODS: 20 individuals with ACLR (months since surgery = 35.8 ± 18.9; age = 21.4 ± 2.9 yrs, 9 male) and 13 uninjured controls (age = 22.6 ± 3.0 yrs, 5 male) participated. CRF (VO2peak) was assessed via a graded, discontinuous treadmill test. Treadmill time to exhaustion was also reported. %BF and fat mass were estimated using air displacement plethysmography. Groups were compared using Mann Whitney U tests. RESULTS: Individuals with ACLR had a shorter treadmill time to exhaustion (ACLR: 22.2 ± 2.4 min, CON: 25.2 ± 2.6 min; p < 0.01) and a lower relative VO2peak (ACLR: 43.0 ± 7.6 ml/kg/min, CON: 48.6 ± 7.5 ml/kg/min; p = 0.04). Individuals with ACLR had greater fat mass (ACLR: 17.7 ± 6.7 kg, CON: 12.9 ± 4.3 kg; p = 0.02) compared to uninjured controls, but no significant differences in %BF (ACLR: 25.2 ± 8.4%, CON: 19.8 ± 5.7%; p = 0.07) or BMI (ACLR: 24.0 ± 3.5 kg/m2, CON: 22.1 ± 2.7 kg/m2; p = 0.07) were observed. CONCLUSIONS: Individuals with ACLR had lower CRF as compared to uninjured peers of a similar age and gender. This is concerning because research suggests low CRF (lowest quartile or quintile) is associated with increased risk of CV disease or all-cause mortality, independent of other CV risk factors. Although individuals with ACLR displayed poorer characteristics of CV health, CRF values were still within an acceptable range (mean VO2peak: 43 ml/kg/min) and would be categorized above the lowest quartile for women (65th percentile) and men (30th percentile) ages 20-29. Clinicians should promote maintenance of adequate CRF in the years post-ACLR due to the possible negative long-term CV health implications associated with low CRF. Supported by the ACSM Foundation Doctoral Student Research Grant.