AMRAP stands for “as many reps as possible.” It is a common term in CrossFit-style workouts. It is also associated with the term “metcon” or “metabolic conditioning”. Metcon is often used for high-intensity interval training (HIIT) workouts. I don’t much like the term “metcon”. For one thing, all conditioning is metabolic conditioning. After all, any exercise will in some way affect one or more of the metabolic pathways, depending on the specificity of the activity. So, I avoid the term, all together.
The application of AMRAP is less clear-cut. There is nothing wrong with the phrase. It simply indicates to do as many repetitions as possible (usually in a prescribed time limit). There are, however, somethings to consider when performing AMRAP.
Goals. When applied to HIIT—perhaps, the better label might be HIIRT (high-intensity interval resistance training), AMRAP in a limited period of time can be appropriate. This is intended to maximize intensity, though does not necessarily mean the exerciser will be exercising to the desired intensity (i.e., there is room to be “dogging it”). If the goal is improved cardiorespiratory fitness, such circuit-style (HIIRT) exercise is limited. Likewise, these workouts are not specific to muscle hypertrophy or building strength. They are, however, quite suitable for burning calories for fat loss.
When AMRAP is applied to weightlifting (e.g., the bench press), it is essentially the same lifting to momentary muscular failure (the type of training popularized by Art Jones and Nautilus in the 1970s). As such, there is usually some desired repetition range—e.g., 8-12 repetitions. The higher the number of repetitions performed the less intense the exercise (relative to the 1-RM). Very high-repetitions is specific to muscle endurance—not hypertrophy and strength. To be specific to cardiorespiratory endurance the duration of the HIIRT should be at least 20 minutes. (I have discussed the parameters of the IE1 “Tabata” protocol on several occasions. To be effective at improving oxygen consumption, the short 20-s bursts associated with “Tabata” (8 repeats of 20-s high intensity + 10-s rests; 4-minutes total exercise) must exceed 170% of VO2max—which approaches impossible for the average exerciser.
Safety. As one approaches his/her maximal repetitions, technique tends to break down and thus increases the risk of injury. Any workout requiring AMRAP should emphasize “with proper technique”. Otherwise, injury is somewhat inevitable. This is especially a concern when weights are involved. I am particularly concerned with workouts that ask the exerciser to do AMRAP of Olympic-style exercises, e.g., cleans. Such exercises were never intended to be performed for much more than 3-5 reps (and not without resetting between reps).
There is nothing inherently wrong with doing AMRAP in a workout. It is just necessary to define the parameters and match these to the intended goals. It is essential that the exerciser: 1) always maintain proper form, 2) put the appropriate time limits on the sets (specific to the intended energy system—e.g. 15 s for ATP-PC, 30 s for glycolytic, etc.), 3) remember recovery and 4) consider these workouts for burning fat and lift weights and do cardio-specific exercise for strength/hypertrophy and cardiorespiratory endurance, respectively.
Carpe momento!