PURPOSE: To compare the serum cartilage oligomeric matrix protein (COMP) and hyaluronan (HA) response to walking (high-repetition loading) and resistance training exercise (low-repetition loading) in males and females. METHODS: 15 males (age: 28 ± 6 years; BMI: 24 ± 2; mean ± SD) and 15 females (age: 26 ± 4 years; BMI: 23 ± 2) completed both a 40-min walk at 80% of maximum heart rate and a 40-min lower body resistance training protocol, separated by a minimum of 48 h. Serum COMP and HA were determined at rest, immediately post, and 30-min post exercise. Resting femoral cartilage thickness was also measured using ultrasonography. RESULTS: COMP increased following walking (28.9%; P < 0.001) and resistance training exercise (26.0%; P < 0.001), remaining above baseline post-exercise following walking (mean difference: +28.3 ng/ml; 95% CI 3.8-52.8 ng/ml; P = 0.02). Although the exercise response did not differ for gender, COMP concentrations were higher in males than in females at all time points (all, P < 0.001). In contrast, HA concentrations did not change following either modality of exercise. However, females demonstrated higher HA pre-exercise (37.7 ± 17.8 vs 26.2 ± 12.8 ng/ml; P = 0.006) and immediately post exercise (38.0 ± 19.0 vs 28.2 ± 15.5 ng/ml; P = 0.033) compared to men. Finally, following adjustment for body size, femoral cartilage thickness was greater in men compared to women (notch: 2.66 vs 1.74 mm, P < 0.001). CONCLUSION: The effect of a single bout of lower body exercise on serum COMP and HA is independent of exercise modality in healthy men and women. Furthermore, having thicker femoral cartilage and higher baseline COMP in males does not appear to influence how the cartilage responds to exercise.