Increase Metabolic Stress for Size and Performance

STACK Expert Dalton Oliver describes three strategies that increase metabolic stress to produce greater workout gains.

Want a quick surge in performance enhancement? Creating metabolic stress might be your answer. This is a way to maximize your energy turnover during a training session, to increase anabolic hormone production and muscle fiber recruitment.

To create metabolic stress, you need to do exercises for moderate to high repetitions. But that doesn't mean you should forgo the heavy stuff. Drop, compound and cluster sets can build your metabolites.

Drop Sets

Drop sets are performed by using a high load until fatigue, dropping the weight by 20 to 50 percent, then immediately performing a subsequent set with little to no rest. One example of an effective drop set is squatting with a weight you can only lift five times until fatigue. Within 10 seconds, drop the weight by as much as half and jump right in to the subsequent set, repping out until fatigued.

RELATED: Drop Sets: What They Are and How to Use Them in Your Workout

Compound Sets

Compound sets are often mistaken for their fat-burner cousins, supersets. Although the two approaches are similar, they have very different purposes. Compound sets involve using two exercises back to back that target the same muscle group. Supersets target opposing or unassociated muscle groups.

The goal of compound sets is either to emphasize different heads of the same muscle or engage other muscles to continue moving through the range of motion, keeping the target muscle active. Either way, compound sets thoroughly deplete the target muscle's energy stores, increasing metabolic stress at the specific muscle group.

RELATED: Compound Exercises That Build Muscle Twice As Fast

This strategy leads to a level of metabolic stress well beyond what we see from a single exercise. Typical compound sets consist of either two pulls or two presses in a row.

An example of a compound set (again, different from a superset) could be a Pull-Down followed immediately by a Seated Row.

Note: You can use supersets to condense more total work in a smaller amount of time or to further spike your heart rate. They play a valuable role in time-sensitive conditioning routines, but they have less value for hypertrophy programs.

Cluster Sets

This strategy involves performing a set to fatigue, then resting only 5 to 15 seconds before executing more reps. They can be very difficult, and acidosis (that burning sensation) becomes a limiting factor. Cluster sets are applied most often to isolation exercises, since compound movements are normally limited by factors other than hydrogen build-up. A common example: Leg Extensions for 12 reps, rest for 10 seconds, then more reps until failure.

RELATED: Single-Leg Extension

One last thing: Intensity seems to be the key to signaling hypertrophy. Whether we use light weights for high reps or heavy weights for low reps, reaching failure is standard in hypertrophy routines. So why not try both approaches? Going until failure with heavy loads leaves you able to continue work with lighter loads (if you plan recovery appropriately).


  • Tesch PA, Colliander EB, & Kaiser P. (1986). "Muscle metabolism during intense, heavy-resistance exercise." Eur J Appl Physiol Occup Physiol, 55(4):362–6.
  • Tee JC1, Bosch AN, & Lambert MI.(2007). "Metabolic consequences of exercise-induced muscle damage." Sports Med, 37(10):827-36.
  • Brad J. Schoenfeld. (2013). "Potential Mechanisms for a Role of Metabolic Stress in Hypertrophic Adaptations to Resistance Training." Sports Med, DOI 10.1007/s40279-013-0017-1

Photo Credit: Getty Images // Thinkstock