Notes on Training Intensity – Part 1: High Intensity all the Time?

This is part 1 of (potentially) a 3 or 4 part blog series. Read and enjoy, feel free to comment!

There are a lot of simple statements about training that just make sense. They tend to get overlooked by virtue of their simplicity and logic – overshadowed by more outrageous claims and marketing hype. The truth is that if you can keep your training philosophies as simple as possible, you will progress. In this blog I’m going to discuss training intensity, and by “intensity” I am referring to the level of effort/discomfort/stress of a training session. In support, I will supply two basic statements that if followed, will provide the guidance to higher and higher levels of physical fitness.

1. You can’t train high intensity all the time

2. Never underestimate the value of submaximal training

I’m sure to some of my CrossFit crew the first statement might seem like sacrilege, but give me a shot and I think I’ll convince you that I’m on the right side of the law. For those of you involved in other forms of training for sport, these concepts will resonate immediately.

Firstly, here are my observations of what happens to people who train to maximum (or close to maximum) too regularly:

1. They experience massive initial gains (GOOD – sort of)
2. After 3 months to a year they start to accumulate muscle and joint pain
3. They begin to get nagging injuries
4. Their “maximum” effort becomes, over time, a lower and lower percentage of their actual maximum capability
5. They burn out

So what exactly is happening here? Definitely the process of training to maximum is a powerful stimulus for adaptation – hence the very rapid gains in strength and overall fitness we often see in programs like CrossFit. Depending on the initial fitness level of the individual who starts such a program, they may progress very well for up to ~2years following a high intensity training program (generally, the lower the initial fitness level, the longer the person will progress in this system). After that point, there is a stagnation and then regression in performance and ability to tolerate high intensity work (increase in injury and symptoms of overtraining). For some individuals, this process may only take 6 months and is also dependent on the frequency and structure of the training they are performing (i.e. Crossfit.com versus a more progressive plan).

The main issue for both performance and overall body health is that by nature, high intensity work is low volume. Low volume work (either high or low intensity) does not inherently provide enough of a base level of development from which to progress from. High intensity work exposes muscles, joints, and connective tissues to aggressive stresses repeatedly – stresses that those tissues are not adequately prepared to deal with.

High intensity work is also high stress. This has both physiological and psychological impacts. Physiologically, too much intensity leads to a pervading environment of stress on your both your nervous and musculoskeletal systems. This stress leads to excessive muscular tension and alters hormone balance. Psychologically, high intensity is a fatiguing objective to obtain at every session, and can lead to lower interest in training and less motivation to push harder when the workout requires it.

These factors combine to create the situation I outlined above – “high intensity” becomes “moderately high intensity” over time by virtue of the inability of the body and mind to support true high intensity work. The fallacy is that the individual who is undergoing this performance decay will feel that they are executing at maximum output when in actual fact they are well below their potential.

In part 2, I'll discuss the value of submaximal training in support of high intensity activity. Comments, retorts, and questions are welcome!