Metabolic Conditioning (Metcon)

What is it? Metabolic training is refers to conditioning exercises aimed at increasing the storage and delivery of energy for any activity. There are three distinct biochemical means that energy is provided for human action. These metabolic pathways or “engines” are known as the phosphagen, glycolytic and oxidative pathways.

The phosphagen pathway provides the bulk of energy used in high-powered activities, namely sprints and things that last less then 10 seconds or so. When you are going all out, 110%, you are using this metabolic “engine”. Think Olympic level 100m sprints.

The glycolytic pathway is in charge of moderate powered activities, lasting up to several minutes. So when you are holding strong at 80-90% or so for several minutes you’re using the glycolytic “engine”. Think 400m sprints.

The oxidative pathway provides the energy for low powered activities, lasting in excess of several minutes. Think running a mile or more.

I’m sure we’ve all experience those activities before, so think back to how they felt, in a hard sprint, it is not possible to maintain that pace for more then 10 or so seconds. That’s because you’ve exhausted that energy system, so you slow down and “jog it out” the last few strides. That’s where you are making the switch to a new energy system. And just like in the sprint, if you were to run a hard 400m or 800m (1-2 laps of a standard track) you won’t be able to keep that pace for 2 more laps. Unless of course you are really really fast and can fit more laps in 1-2 minutes of running.

You might also remember that you didn’t feel “out of breath” during the shorter, harder runs, whereas during the longer slower effort you feel out of breath during the effort. You’ll sure feel out of breath afterwards, but think about during. The reason you don’t notice your breathing as much during the really short hard sprint, and not until closer to the end of the medium length effort, is because the phosphagen and glycolytic pathways are anaerobic, and the oxidative is aerobic.

The phosphagen and glycolytic (anaerobic) systems generate energy without the benefit of oxygen, whereas the oxidative (aerobic) system requires oxygen for energy production.

Molecular biochemistry, and bioenergetics is quite complex, so we’ll try to get around all the jargon and get down to the “how does this affect my training” nitty gritty. So for that we will talk about the 2 types of efforts, and not focus on the 3 pathways used, those 2 efforts being anaerobic and aerobic. The key thing we need to remember is that anaerobic is metabolically unsustainable, whereas aerobic exercise is sustainable. Generally speaking, all out efforts lasting 2 minutes or less are anaerobic, and anything lasting in excess of several minutes is aerobic.

Now this is getting quite simplified and generalized, but we’re trying to give you a racecar driver’s sense of auto racing, not a mechanical engineer’s. Both have their place but only one drives the car on race day.

It should be pretty evident that anaerobic is high powered and aerobic is low powered, based on the fact that one is sustainable, and the other is not. Clearly if it’s too hard to keep going doing past a couple minutes, it’s hard work, therefore demanding a lot of power. Power or intensity, and duration of effort are inversely related; a 100m sprint pace is considerably faster then a 1 mile pace.

Aerobic exercise is nearly universally regarded as being heart protective, but there is compelling evidence that shows that anaerobic exercise is at least as heart protective as aerobic exercise. Though aerobic exercise is widely recognized as being the ideal vehicle for fat loss, recent studies have shown that anaerobic exercise is a vastly superior protocol for fat burning. Anaerobic exercise builds muscle; aerobic exercise burns muscle - period. On this point there is no intelligent debate. Compare the look of sprinters to long distance runners. Here a picture is indeed worth a thousand words.

marathoner sprinter
(aerobic) (anaerobic)
Unfortunately the effect of long slow distance endurance work has been slow to spread into many anaerobic sports. It is still common to find boxers and martial artists who think that LSD (long slow distance) training (roadwork) is essential to their fight endurance, but this could not be further from the truth.

Conversely, anaerobic training can be hugely beneficial to endurance athletes! Not only does it support and build more muscle, but also it gives them added “kick” to win close races and finish strong. You can also use anaerobic training to build aerobic endurance without sacrificing muscle. You can accomplish this thru interval training.

Interval training is simply anaerobic training with controlled rest periods. This allows you to perform a high volume of high intensity anaerobic efforts. Interval training benefits both anaerobic and aerobic systems, but by how much and to which system? We can build intervals to be predominantly stressful to either system.

Sprint (Phosphagen):
10-30 seconds of work, 30-90 seconds of rest, 1:3 ratio, 25-30 repetitions

Mid-Distance (Glycolytic):
30-120 seconds of work, 60-240 seconds of rest, 1:2 ratio, 10-20 repetitions

Long-Distance (Oxidative):
120-300 seconds of work, 120-300 seconds of rest, 1:1 ratio, 3-5 repetitions

That’s just an example of a way to do some interval work. Now this is not limited to running, you could use these interval lengths for any type of exercise, be it, maximum number of pull-ups, squats, pushups, sit-ups, etc, etc…

A great interval for doing bodyweight exercises is the Tabata interval, developed by Dr. Izumi Tabata. It is simply 8 rounds of 20 seconds of maximal effort followed by 10 seconds of rest, lasting a total of 4 minutes. During his experiments, he found that his interval-training group showed a greater increase in their VO2 max then the group that trained for 60 minutes at a moderate intensity.

So, your homework is to play with intervals. If running is your thing throw in some of those intervals into your training, subbing an LSD day with an interval training day and see how it effects you over a few weeks.

If you’re like me and LSD running is not your bag, then try some tabata squats. We should by now know how to do a proper squat, but if this is your first time reading my articles go back and read the rest! Get a stopwatch and a friend or go here and set up an interval timer for 20 seconds on and 10 seconds off. Do as many squats as possible in the 20-second work period for 8 rounds. Your score is the lowest number of squats done in a single round.

Chris Walls is a Personal Trainer at the newly opened Crossfit Kelowna training centre. For more information on Crossfit, please visit http://www.crossfitkelowna.com