Rogatzki, MJ, Wright, GA, Mikat, RP, and Brice, AG. Blood Ammonium and Lactate Accumulation Response to Different Training Protocols Using the Parallel Squat Exercise. J Strength Cond Res 28(4): 1113–1118, 2014—Three parallel squat protocols with equal total work volume were used to determine the metabolic response of resistance exercise with different practical training protocols combining program variables in the way that they are typically prescribed in field. Sixteen men able to back squat 1.5 times their body weight participated in the study. Individualized muscular endurance (ME), strength (STR), and hypertrophy (HYP) squat workouts were developed based on a 1 repetition maximum back squat. Each protocol was performed 3–7 days apart in random order. Venous blood was obtained after 5 minutes of seated rest both before and after each workout for ammonium and lactate analysis. The ME protocol (79.8 μM [SD = 45.4], 95% confidence interval [CI]: 55.7–104.0) produced a greater change of plasma ammonium than both the HYP (45.3 μM [SD = 34.5], 95% CI: 26.9–63.6, p = 0.017) and STR (31.7 μM [SD = 52.3], 95% CI: 3.9–59.6, p = 0.006) protocols. Change of blood lactate concentration from resting levels to postexercise levels was significantly different (p = 0.005) between ME (6.1 mM [SD = 2.9], 95% CI: 4.6–7.7) and STR (3.9 mM [SD = 2.5], 95% CI: 2.6–5.2) protocols. The main finding of this study is that blood ammonium and lactate seem to accumulate in response to an increasing number of repetitions with decreasing rest time between sets. As consequence, a greater number of repetitions should be added to a resistance workout, along with a shorter rest time between sets when training for events that induce a large metabolic load. The metabolic accumulation associated with high repetition exercise may represent the need for longer recovery time between these types of workouts compared with workouts using a low number of repetitions.