Previous research has demonstrated a dose-response of collagen supplementation on a blood-borne biomarker of collagen synthesis (procollagen type I N-terminal propeptide (PINP)) following jump rope (skipping) exercise (Shaw et al., 2017). However, skipping does not overload the muscle-tendon unit (MTU) to the same degree as resistance exercise (RE), therefore these data may linked to bone rather than MTU collagen turnover. We therefore investigated the impact of hydrolysed collagen (HC; 0 g, 15 g, or 30 g) supplementation on serum PINP following high-intensity RE. Ten resistance-trained young men (mean ± SD; age: 26.03 ± 3.25 years; height: 177.9 ± 3.63 cm; mass: 79.7 ± 7.03 kg) participated in three trials (separated by a 7-day washout period) in a double-blind, randomised cross-over design study. In each trial, participants consumed a beverage comprising HC plus 50 mg vitamin C prior to performing 4 sets of 10-RM back-squats. Venous blood samples were collected at REST prior to HC ingestion, 2 h-POST RE, and 6 h-POST RE and the sera were analysed for PINP via ELISA. Serum PINP concentrations for 0 g, 15 g and 30 g HC, respectively, were 20.27 ± 4.64, 19.97 ± 3.53, and 20.56 ± 3.99 ng/mL (REST); 20.52 ± 3.92, 20.12 ± 3.42, and 19.65 ± 4.17 ng/mL (2 h-POST); 21.38 ± 4.42, 19.20 ± 3.71, and 19.77 ± 5.05 ng/mL (6 h-POST). Serum PINP concentration did not change as a consequence of HC dose, time or RE. Our results suggest that there is either no HC dose-response following high-intensity RE on lower-limb MTU collagen synthesis, that serum PINP is not a sensitive biomarker of MTU collagen synthesis, or that serum PINP increased during RE but had returned to resting concentration by 2 h post RE. Skipping is likely a more potent stimulator of bone collagen turnover, for which impact force is more important than high muscle forces, thus potentially explaining the discrepancy between our findings and those of Shaw et al. (2017). Previous studies have shown that serum PINP increases during high-intensity exercises (running and drop jumps) but returns to resting levels immediately after finishing exercises (Scott et al., 2011; Clifford et al., 2019). Future studies investigating the dose-response of collagen supplementation before RE on MTU collagen synthesis should measure serum PINP immediately after RE and ideally include direct measurements of MTU collagen turnover.