What is Progressive Over-Load

Not what we think!

Progressive Over-Load/Ramp Rate

I did a search on Academia web site. Over 17,000 papers on progressive overload in endurance training and various other searches did not come up with any research that addresses the role of progressive overload or ramp rates in endurance training. If one Googles the term progressive overload, there are a lot of articles that address the theory of the principle of overload but not studies validating this principle. I am not questioning the need to increase the loads of training over the years of athletic development the evidence supports this, but rather how we approach or distribute the load over a training year.

Since I have been involved in high level training, for more than 50 years now the theory of overload has been prevalent. But what is it, how is it measured and if we can answer those two questions, then is it effective? I suppose this is also related in some way to the Super Compensation theory, which like progressive overload is a theory not well researched. I should point out in my experience and what I have observed in many athletes, progressive overload more often results in over training than in improved fitness and performance.

The first question is what load we are interested in progressing in and how are those loads measured. Is this load defined as the speed/pace or power we produce in training, is it the internal physiological load, is it the duration of time we spend training, or even the distance covered. The second question is, is increasing the load required to facilitate increased adaptation, or does fitness improve with chronic exposure to stimulus. Finally, the third question is if progressive overload is a thing, how do we decide how and when to increase the load, more volume, higher intensity, more training sessions etc.

My first assumption for most coaches is that the typical determinants of progressive overload or ramp rate are guided by the duration of training/hours, or the distance covered. However, none of those metrics are remotely close to defining load on the body because both are missing the key element of intensity.

I will base my discussion based on TRIMP loads, which some will argue favors duration over intensity, which is true, but it still provides a consistent value for training loads for comparative process. But even at that it is missing a factor of external load.

If I ride my bike two hours a day, five or six days per week for three months, at some point I will not improve my fitness? Experience has shown that this is simply not the case or the outcome training effect. I have known in following Firstbeat TRIMPS for many years now that the optimal load on any given day, is about 1.2 ratio of the current chronic load with a range of loads in the week between .9 and 1.2 of the chronic loads. More than that and most athletes will not adapt to the load. Of course, everyone will always have races or some unique training sessions that may deviate from this guide. But not often and most of the training should fit within these norms.

To follow this logic, one would have to believe that to do an ultra-event successfully we would have to replicate that load in training. As Inigo San Millan has stated, training at the first increase in lactate above baseline, the mitochondria are saturated with lactate, and this is providing adequate stress and stimulus for endurance training. With training over short or even moderate time periods, the aerobic system is stressed to the point where adaptations continue to occur, sort of a compounding effect, even though the duration has not progressively increased much or only at a slow rate. But if training is working something does increase, that is the pace or power we can sustain at a sub-maximal heart rate.

None of what I am suggesting minimizes the importance of the volume load of training. We know that needs to increase over the years of training to fully develop an athlete’s potential. Rather what I want to discuss is the concept of overload and the rate of load increase that is sustainable. Many of these old models were to what I did as an athlete, start the training year in May at 50-60 hours of training, increase each month, reach a high point at 100-120 hours of training in November. Then taper into racing season and expect a “magical” increase in performance when many of the factors of improved fitness and adaptation occurred along the way. The volume increases 5-10 percent per month without recognition that the previous month may not have provided the developed adaptation and fitness to be able to make the next steps in the following months. For me, I was able to produce some very good performances, but they were in no way sustainable or predictable.

The following chart illustrates a hypothetical ramp protocol versus a nearly consistent training volume for 4 week periods. Both generate about an 800-hour year. In my experience, what we are seeing in elite performers is that the nearly consistent loads are much more effective and lead to sustainable and improving performance.

I believe that too many athletes again and again attempt these aggressive ramp rates, some more than others, and expect somehow that fitness will follow just because they increased the loads from period to period. I have also seen, especially in skiers, they go to training camps hosted by the national team, they train much long, much harder with 30-40% or more increase in loads above what they have been doing and as I have assessed their HRV data, but the time they have recovered from the camp, much of the potential benefit from those big increase in loads has been lost.

In the following example of both recovery and TRIMP training load for this successful mater cross country skier. The total training load increases from about 500 per week, to about 600 per week. That is about a 20% increase in load over the entire year, or less than a 2% increase in load per month. Just for reference that is on average less than 10 TRIMP per week, which equates to about 8 minutes of easy training, or about 2 mins of high intensity training. So virtually nothing. Yet we know from both testing data and performance data this athlete got better every week during the race season.

In implementing training this year the above athlete started the training season in May at about 600 TRIMP per week and by the end of the season will be at 700-750 TRIMP we can make this kind of increase because the athlete tolerated and adapted to last years loads very well, and because the recovery was well controlled we did not need excessive down time at the end of the season so we can build year upon year. Basically, starting the new year at the ending level of the previous year.

Also, of equal importance we can see from the HRV RMSSD data that expect for two brief periods of illness the RMSSD stayed in a very tight range of normal, except for two brief periods of illness. I believe this reflects the type of recovery and adaptation to training we should expect to see. This is not an isolated example I have seen the same trends and response in cross country skiers, national champion mountain bike racers and good triathletes.

We have seen the same trend in Scandinavian cross-country skiers based on published data. The top athletes trained for 80-100 hours per month, very little or small variations from month to month, VO2 max, high intensity training is always part of the plan, with most increase in training load coming from increasing the loads of high intensity training.

With what I have experienced and observed with athletes at all levels. I would question the need for overly aggressive ramp rates, at least in terms of the volume or distance metrics of training. I will surmise that with effective training the increase in speed, pace or power output does increase, which may suggest a ramping of training, but at a similar slow rate.