This post continues a little saga I have going on about the aerobic system and fat-burning in relation to other aspects of training, mostly due to my continuing work with Phil Maffetone and MAF Fitness.
People often ask how—or whether—strength training fits into the MAF method, particularly during times of aerobic base building.
My answer, of course, is YES. (Provided, of course, we usefully define what “strength training” means).
The MAF method prescribes exclusive aerobic exercise—defined as exercise that has a virtually nonexistent anaerobic component—in 3 different situations:
- When ill, injured, or overtrained.
- When recovering from any of the three.
- When doing a period of sports-specific aerobic base-building.
In all other situations, we recommend that 80% of all athletic activity be aerobic, while the remaining 20% (which includes competition) can be anaerobic. But this post I want to talk about how strength training fits into situations 1-3.
The foremost problem with asking how (or whether) strength training fits into these situations is definitional. Strength training, broadly defined, is training which allows the body to exert more force into its environment. And based on this definition, some, but not all, strength training is accepted.
The big question is this: what kind of training is aerobic?
For that, we have to look at why the body recruits the anaerobic system for certain activities. The answer is twofold: (1) because it needs to produce a lot of low-end torque—a relatively high amount of power in a short amount of time—and (2) because that activity is going to last for a few seconds—before anaerobic channels exhaust themselves.
This rules out one particular kind of activity: heavy strength training where the body fatigues itself after a few repetitions. Here is your benchmark: if you can only do 5-8 repetitions before exhaustion, it is because you have recruited anaerobic channels.
This holds regardless of whether the heart rate is “low enough” to be aerobic—or hasn’t climbed enough to “be anaerobic.” So, my suggestion to people is to do strength exercises of more than 12 repetitions.
But there’s another caveat: exercises of more than 15 repetitions are not necessarily aerobic. (For example, a 100 yard sprint consists of 65 repetitions—65 steps—at best). So, for these high (15+) repetition exercises, it’s important that the heart rate reflect that the body is working overwhelmingly aerobically—at what Dr. Maffetone describes as the MAF Heart rate.
Good examples of strength exercises with the potential to be aerobic are: proprioceptive (very light load) deadlifts and squats, push-ups, pull-ups, etc.
I also often recommend stability training as an acceptable supplement for periods of “exclusive” aerobic base training. However, this comes with an important caveat: while stability training is very low-intensity work—which means that it very rarely interferes with aerobic base building—strictly speaking, it is an anaerobic exercise.
Stability is achieved and maintained by very quick, continuous movements of the small muscles of the body, in order to counteract tiny losses of balance before they become serious. Providing stability is therefore largely the responsibility of extremely fast-twitch Type IIX muscle fibers, which rely primarily on anaerobic uses of sugar in order to produce energy quickly enough.
Whenever we are training stability, we are training the anaerobic system.
Is this a problem for aerobic-only training? Not in most cases. If you think about it, “aerobic-only” running has a massive stability component: the entire body must be stabilized every step through constant use of Type IIX muscle fibers.
But these stabilizations are small enough in comparison to the primarily aerobic work of running, that anaerobic debt doesn’t rack up in a way that transforms aerobic running into “anaerobic exercise.”
The point at which stability training becomes anaerobic is when it starts raising the body’s stress levels—when it asks the body to exceed the aerobic threshold (a.k.a. the MAF heart rate).
Whenever you want to do stability or strength training without hindering your aerobic base-building, take your heart rate monitor with you. It’s (almost) as easy as that.