Isolate the chest muscles before moving on to compound moves like the dumbbell bench press.
The idea at first glance is counterintuitive — just why would you tire out a muscle before challenging it with a major lift? For instance, blasting your pectorals with flyes and then attempting to bench press, or burning out your quadriceps with extensions before launching into a set of hack squats?
If your goal is to challenge your personal-best poundage on that exercise, you’re right to be skeptical. But if instead your goal is building maximal muscle mass, well … you may want to put aside your doubts and take a closer look at the Weider Pre-Exhaust Principle.
The pre-exhaust principle was devised to help bodybuilders fully stimulate larger bodyparts that might otherwise be held back by relatively weaker ancillary players during multi-joint (i.e., compound) exercises. For instance, when doing presses for chest, the triceps are involved too — and being smaller, may tire during a press before the prime mover approaches muscle failure. Thus, the theory goes, you end up terminating a set too early.
To counteract the problem, in using this principle, you first “pre-exhaust” the prime mover by doing a single-joint exercise — such as a pec-deck flye, which doesn’t directly involve the triceps — thus slightly weakening the pectorals and nudging them closer to failure when it comes to pressing.
The same argument could apply to biceps during pulling movements for the back; it’s also been used for leg presses and hack squats, with bodybuilders doing leg extensions first to decrease the dominance of their quadriceps during those lifts.
NOT FOR NEWBIES?
Admittedly one of the more controversial Weider Principles, some studies have set out to demonstrate the theory underlying the pre-fatiguing technique is faulty. Other detractors point out it’s so specialized that it’s really only valuable for already highly developed bodybuilders.
As to that latter point, it’s true to a degree — beginners shouldn’t even consider pre-exhaust, as it’s much more important to build a foundation of strength first. A beginner is best served front-loading their workouts with multi-joint moves and back-ending them with isolation exercises. For example, a preferential order for a chest workout would be incline presses, flat-bench presses, dumbbell flyes and dips or push-ups as a finisher.
Where pre-exhaust starts to become more valuable is for intermediate to advanced lifters, those with a year or more of consistent training experience. At that point, it becomes one of many useful techniques in the arsenal. Not that pre-exhaust is better than others, like rest/pause, negatives, partials and compound sets, just to name a few — it’s not.
But what it provides is yet another way to tweak a workout and provide a muscle a unique stimulus it’s not used to. Such change-ups are vital as your body becomes more and more accustomed to your weightlifting sessions. Complacency in approach and workout design leads to development plateaus, and that’s when a technique like pre-exhaust can make a demonstrable difference.
And what of those studies? The most recent, published on the Applied Physiology, Nutrition and Metabolism journal’s website in August 2014, concluded that a 12-week protocol of pre-exhaust training “offers no greater benefit” in muscle mass or strength gains than a straightforward training routine.
Problem is, the U.K.-based researchers dropped the ball in many respects, perhaps most notably only requiring one set per exercise, which — Mike Mentzer’s “Heavy Duty” philosophies aside — is arguably insufficient when you’re aiming for strength and muscular improvements. Another issue: Only nine males participated in the study out of 39 subjects total, and the average age was 49 (the youngest participant was 36), which skews results when you consider it’s altogether more difficult to add lean mass when you’re older, no matter what training protocol you’re following.
There are two ways to use pre-exhaust. Most people should stick to the more common version of pre-exhaust, in which you do an isolation exercise, then rest 60-90 seconds before doing the multi-joint move. A more aggressive (but not necessarily more effective) option is to do a pre-exhaust superset, where you eliminate the rest period between the two exercises.
For best results, the pre-exhaust technique should be performed early in the workout, ideally just after an ample warm-up. Doing it later, when your prime movers and ancillaries are taxed, would leave you susceptible to form breaks or injury when doing the multi-joint move. It’s best to tackle this challenging technique when you’re at your strongest.
With that in mind, here are potential pairings for each major bodypart, leading with the isolation options followed by the compound exercises: