I had a conversation over the weekend which reminded me of how important is to incorporate a range of exercise intensities into a training program. The conversation was one that I have semi-often and was focused on the importance of not just running hard all the time, which is a common trap people slip into, particularly when the first start running. This is a topic that I have written about before, but not for a while and given its importance I thought it was worth touching on again.
So what do a I mean by having a range of intensities? Really it is about making sure that not all your sessions are about going out and killing yourself. Certainly some of your sessions should be higher intensity threshold work, and perhaps even some where you work your VO2 Max, however, equally important is that the training week should include time spent doing tempo work and even lower intensity steady and recovery work. A complete training program should include all these elements.
Why is this variety of intensities important?
Well going out and trying to smash yourself every session is simply not sustainable. Too much high intensity work ends up being unenjoyable, inefficient and can easily lead to injury. Why? Well for a number of reasons.
Firstly, to effectively grow as an athlete, you need to work all the intensity zones. Spending time in each zone serves a purpose and each of these purposes is important. Threshold work to drive improvements in power and speed, tempo work to build strength and muscular endurance, steady to safely build fitness and volume and easy work to aid recovery. Each of these zones serves a purpose and so to build a complete athlete you need to be doing work in each of them. It can be tempting to think that you should be working hard every day. Athletes like to hurt and often if they aren't hurting then they can think they aren't training hard enough. However, as you can see if you are spending your time training in only one zone then you aren't getting the benefits that come from training in the other intensity zones. Really by training hard, all the time, you are short changing yourself, you aren't getting the full benefit for the amount of effort you are putting in
A person's body also isn't capable of backing up high intensity sessions day after day, there isn't enough recovery time. If a person tries to train at high intensity all the time then the average intensity and quality of those sessions ends up dropping. As the intensity of these sessions drop the sessions stop achieving their purpose. If you are trying to do a threshold session, but can only hold tempo intensities, then you aren't doing a threshold session at all and aren't getting the benefits that come with it.
Something else to consider is the enjoyability of the training. Sometimes we lose sight of it, but the sports we choose to spend time doing is supposed to be fun. While athletes like to train hard and hurt themselves, it takes a lot of mental energy to do so. It can be very hard to try and gather the mental energy necessary to go out and smash yourself day in and day out, eventually you stop being able to find that energy. This is one of the arguments against high intensity boot camp type training. They are effective at driving fitness and weight loss, but have a low rate of long term compliance. Having a bit of variety in intensity allows some fun to come back to training. The hard training is still there, but between those hard sessions are the steady ones, the tempo work, the recovery etc. When I have got athletes to start working in a variety of zones, one of the first things they have said is how much more they are enjoying the training again as not every session is a smashfest. Fun training is sustainable training.
And finally one of most important reasons to incorporate a range of training intensities into a program is for injury prevention. When you go hard it puts more strain on your body. This is particularly true for running where the probability of injury increases exponentially with intensity. At steadier intensities the duration of the session may increase but the risk of injury does not. Using a mixture of short hard work and longer steady sessions and everything in between allows a person to build capacity and performance without increasing their injury of risk too much. This then allows people to train more consistently long term, which is when the real improvements come.
So there you go, as you can see there are numerous benefits of working all zones into your training. Such is the importance of incorporating intensity variation in training that I would consider it an essential component of any well designed program.