For Athletes: Supra-Maximum HIIT Causes The Most Physiological Improvements

How do you eek out even better physiological performance when someone is at the top of their game - in performance? Can a sprinter sprint faster? Can a skier ski better? Can a baseball pitcher throw faster and more accurate?

What are the factors that improve performance?

If I was asked by a professional sports team, an Olympic trainer, a college team manager what could I do to improve the physiological output of even the highest of their performers here's what I would say in four words:

Supramaximal high intensity intervals

Not submaximal exercise. And certainly not jogging on the treadmill, going up and down on the elliptical, or hunching over on a bike or a rower; these are nothing close to submaximal exercise training, but are characterized by prolonged, continuous activity.

What you have to be careful about in supramaximal exercise is the safety factor - is this exercise that you are attempting, safe? Are you going to fall down or risk injury by doing this exercise? Another thing to consider is the affect of gravity. Gravity can play a role in exercise to some extent. What I'm talking about is a purely user-induced all out high intensity bout of exercise. These athletes are going to lay down on their back and engage in almost-maximum resistance, as fast as possible, for a short period of time.

I would put their star athletes on the Myoride exercise machine, increase the resistance on all four independently moving arm and leg devices to what I thought is close to their maximum intensity yet which allows them to perform a full body, complete range of motion, supramaximal intensity interval in 20 seconds. At exactly 20 seconds, we would get their maximum heart rate which should be double their resting pulse, at least, maybe 30-40 bpm more. As well, I would want to know the number of complete arm/leg cycles in cycles per minute (cpm) because this is their velocity, the speed at which they perform the interval. This is very critical because this speed will fail on an upcoming interval.

high intensity training

After the 20 seconds they are resting. While resting, they're not talking because they are attempting to satisfy the quickly depleted oxygen supply. I'm observing them and most likely telling them what I've noticed in this short time. At the 60-second mark after stopping, I would take their 60-second pulse, mark it next to their maximum pulse, and then do the same at the 120 second mark.

They would rest at least 2 minutes (120 second pulse) and most likely, depending upon their condition, rest another 60 seconds, a total of 3 minutes.

Then the star athlete would repeat the supramaximal burst. And we'd repeat the second half of the interval, the rest cycle of the interval.

But what would happen, even with this star athletic specimen, is that there will come a time, and it happens to everyone no matter how physiologically, metabolically, neurologically intact they are, when their speed or their velocity of arm/leg cycles per minute will fail. They will not be able to keep their arm/leg cadence because, although the resistance has remained the same, the athlete cannot quite recover to the previous velocity.

It is at this exact moment I will lessen the resistance on each limb so this star athlete can continue at the same velocity until another factor plays into the metabolic equation; that is, heart rate recovery. It is when, at the last interval that the heart rate does not recover adequately near to the first interval of the 60-second or 120-second mark that this athlete is done. Done! No more exercise. Under no circumstances do we want our star athlete to over train and lose out on the metabolic benefits they have gained. We allow for the anabolic systems to go to work for recovery and repair. Just these brief periods of rest will allow for recovery. (The next thing we are going to have to determine what constitutes a recovery in these short bursts, as these recoveries are duration-based at 2-3 minutes).

Do you get what just happened? These athletes are using their own power to engage against the resistance set on the machine, yet when they cannot continue at their own speed we lessen the resistance to allow them to complete the supramaximal interval exercise. For the first time, we are able to conduct an athlete-specific supramaximal interval based on their own physiological output.

And, we can always stay ahead of the athlete's ability to perform. In other words, we can always outdo the athlete by adjusting resistance or duration (most likely we don't want to adjust speed because we want the speed, the velocity of the output as high as possible - we would never have the athlete exercise at a less-than-normal speed).

We can improve performance by adjusting these variables! We can certainly adjust the duration - we can let the super athlete go 30 seconds if we want (but why go this long when we can adjust another variable?). Or, we can experiment with this athlete to find how little duration we can engage and still get maximum physiological output. I have experimented with as little as 8 and 10 second bursts of supramaximal intensity. I did not mis-state that, as little as 8 and 10 second bursts! This only makes sense when we can engage as many Type II b muscle fibers as possible but this idea is for another story.

And which of these variables is the most important? Intensity! It is the intensity that drives the machine. In our case, we have an almost insurmountable intensity that we can adjust; that is, the resistance of each independent limb can be adjusted to match the output of the athlete. And we can continue adjusting the resistance independent of duration and velocity.

We want to repeatedly stress the physiological systems so that the body will re-adjust to higher levels of functioning. These physiological improvement are due to the upregulated functions of both aerobic and anaerobic metabolic systems to the energy demand created by the burst interval which will enhance the availability of ATP and creatine phosphate which improves the immediate energy ability of the muscles involved.

This solves the training problem of continuing the same exercise workout without changing any of the variables. Many times, athletes in their trained state will have reached a plateau in the metabolic adaptations that result from their submaximal exercise program.

The point of improving physiological outputs comes down to the changes in metabolism. When the body is repeatedly stressed (it engages in high intensity bouts for a short time) there will be metabolic consequences such as improvements in the capacity of skeletal muscle to buffer H+ ions, and an up- or down-regulation of muscle cation pump. The ability of the muscle to reduce the hydrogen and lactate has to become more efficient when the body is faced with an almost overwhelming stress such as the supramaximal burst.

Because of the dramatic, almost hypoxic state in a supramaximal exercise burst, over time myoglobin levels will increase in response to this hypoxic stress. As well, the rate of ATP and Creatine phosphate synthesis improves over time to provide the short term energy supply needed for the next bout. When there is exercise-induced cellular hypoxia we will get an increase in blood flow, proficient oxygen delivery, better oxygen extraction and fat metabolism in the working muscles after training in the supramaximal state. So, muscle contraction becomes more efficient and physical work capacity increases.

Again, we must be careful with submaximal exercise training. When it becomes habitual, for the any athlete, there may not be further improvements in exercise performance no matter how much of the submaximal training takes place.


Optimizing Supramaximal Intensity Exercise

We are going to optimize the physiological output of exercise by determining the optimal exercise intensity, the length of exercise duration, the velocity or speed of the athlete, number of interval bouts, the number, length and the type (active or passive) of rest intervals, and duration of the recovery days between exercise bouts.

For our elite athletes we can create a far more demanding exercise intensity by careful attention to their resistance levels and still keep watch over the velocity, duration, and the other factors.

We want to push metabolism to gain greater biochemical and physiological adaptations that accompany the supramaximal exercise training occur to provide an increase in muscle cell energy demands.

We want to provide a far greater intensity than that which is actually necessary to perform the activity. In the end, we want our highly trained athletes to have a high aerobic capacity, high lactate threshold (Tlac), and great biomechanics or ease of motion (exactly why we exercise in complete range of motion, engaging the muscles and working the joints throughout this entire range).

These are the high levels of performance and it may be possible that any athlete, no matter in what physiological condition, to gain further improvements in endurance performance through supramaximal high-intensity interval training.  

Reference: Sports Med. 2002;32(1):53-73. “The scientific basis for high-intensity interval training: optimising training programmes and maximising performance in highly trained endurance athletes.”