Fitness results from training, and training is quite simple. There are only two components.
Training = Stress + Recovery
Getting the mix of these two right is not so simple, however.
It’s not easy to determine how great your training stress should be in order to produce fitness, especially while making changes such as including more high intensity in your workouts. There are two common mistakes made by serious athletes, regardless of age, when they enthusiastically make the shift toward more intensity-based stress. They make the workouts too hard, and they space them too closely together. This combination is certain to produce a breakdown such as an injury, illness, or even overtraining.
The solution to this training dilemma brings us to the twin topics of “dose” and “density.” Dose has to do with how great the training load is on any given day. High intensity is high dose. High duration is likewise high dose. On the other side of the coin, low intensity and duration are low dose.
Density is how many high-dose workouts you do in a given period of time, such as a week. The older you are, the less dense your training should probably be. A 30-year-old athlete can typically manage more density than a 60-year-old can. As age increases, the density of training typically needs to decrease. The same is true for dose.
Dose is the controlling variable, and density is adjusted in response to it. As dose rises, meaning the individual workouts become harder, density must decrease to allow for recovery and to avoid breakdown. Conversely, as dose decreases, density can increase.
While both dose and density are concerns of the senior athlete, I’ve found that density becomes the one that gives us the most trouble as we get older. That is due to our slower rate of recovery following high-dose workouts. We can generally do a high-dose session, perhaps even as hard as when we were much younger, but we can’t do several of them in a few days’ time. We need more recovery than younger athletes do after similar workouts.
Like the pause between the notes in a song, inserting recovery days between high-dose workouts gives training a rhythm. Inserting breaks ensures that the density is manageable. As with all things related to recovery—and just about everything else when talking about aging—we each have unique requirements, so I can’t tell you exactly what your dose and density should be. You’ll have to figure that out for yourself based on experience and perhaps even trial and error. But I can help you get started down the right path.
Let’s begin by reviewing the workout dosage for high-intensity workouts. The following table provides examples of high-, moderate-, and low-dose versions of aerobic-capacity, lactate-threshold, aerobic-threshold, and strength workouts.
There are two concerns in planning for density. If the density of your workouts is too great, meaning the hard sessions are spaced too closely together, then you are likely to break down in some way; you may suffer an injury, illness, burnout, or overtraining. If the density is too low, with unnecessary recovery days, your fitness and race performance will suffer because you’ll be undertrained. Given the choice, I’d prefer to see you slightly undertrained than chronically overtrained.
Getting density right is specific to your unique situation. The factors involved include not only the dose of your workouts but also your general lifestyle. If you have a job that is physically or emotionally demanding, density may need adjusting so that the highest-dose workouts have adequate separation between them with plenty of time for recovery. If you go through times when emotional stress is high for any reason, such as a divorce, financial issues, changing jobs, moving, or anything else that upsets you, then the density of training must also be adjusted so that you get more recovery.
Even if you don’t have anything in your life that requires making such adjustments, getting the density of training right is always difficult and somewhat of a moving target. Things change in your life from time to time. Trial and error is about the only way to find out what your baseline density should be. Some weeks it will be spot-on, and at other times it will be all wrong. So once you decide on a density plan that fits your current needs, you may still have to tweak it occasionally as the stress in your life ebbs and flows.
Adapted from Fast After 50 by Joe Friel with permission of VeloPress.