Mixed
High repetition resistance training protocols (approx. 20 reps) generate significantly higher blood lactate concentrations and higher perceived exertion than moderate repetition protocols (approx. 10 reps) when total time under tension is equated.
If you want to maximize metabolic stress (lactate buildup) without changing the total time you spend lifting, do more reps rather than moving slower. For example, doing 20 fast reps creates more metabolic stress than doing 10 slow reps, as long as the total time under tension is the same. Use high repetitions (around 20) to induce this stress.
The results of the present study showed large, significant differences in the post-exercise [bLa-] response between HRP and MRP; although both protocols elicited high levels of MS, elevations in [bLa-] were significantly greater in the HRP protocol.
Why this rating
Randomized crossover design with a robust sample size (n=40) and controlled variables, though limited to acute responses in a single exercise.
Source
Comparison of blood lactate and perceived exertion responses in two matched time-under-tension protocols
Salvador Vargas-Molina et al. · PLoS ONE · 2020
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