Linear and non-linear training programs: Which is best for strength and muscle growth?

For those of us who are on the more serious end of the training scale, who are focused on seeing progression with our training and our goals, then a proper structured training program is the best way to do this. Regardless of what your specific goals are, whether it is to compete in a sport, event or to just improve your physique, it is likely that factoring a few different components of ‘fitness’ such as power, strength, agility, muscular endurance etc. into your training is likely to be needed to get the best possible results, as will having a program that allows for the appropriate progression of these different requirements by manipulating training variables such as frequency, intensity and volume.


The concept of periodisation is this adjustment to intensity, volume, frequency and, indeed, rest over a specific time frame that is focused on developing improvements in performance whilst limiting injury risk or over-training, causing a reduction in performance or improvement.


If we consider muscle strength as an outcome (that I’m sure many reading this will be interested in!), after each training session the body adapts to the stress we have place on it. Therefore with each following training session we then need to create even more stress to force further adaptations. It is for this reasons that as we increase our training age, our initial strength increases in the early stages of training as a novice can be increased by around 50% from our starting point in as little as a few months. This then decreases rapidly with strength gains being made at approximately 2% a year after we reach a training age of two to three years.


This also holds true for muscle growth as well, although the exact figures are difficult to measure. I think after a few years of training that 2-3kg of muscle per year would be considered a good return for most people. This means that periodisation of training becomes more important if we want to keep making consistent progress towards our goals, whatever those goals may be.


In the strength and conditioning literature, there are many different terms to describe different ways of periodisation, however the most common term refers to linear periodisation (LP) and undulating periodisation (UP), which is also often referred to as non-linear periodisation. In LP, the total training block is broken down into periods of weekly micro-cycles, monthly meso-cycles and macro-cycles, which are periods of a number of months. Each phase works at different volumes and intensities to improve overall performance, and with LP training starts with higher training volumes but at lower intensities, then periodically lowers volume and increases intensity until completion of the training block. UP takes a different approach than LP, and changes the volume and intensity on either a daily (DUP) or weekly (WUP) basis. The theory behind this constant change in training volume and intensity is that more frequent changes in the training stimulus will cause greater adaptation, leading to increased strength, muscle growth and performance.


So, what does the research tell us about which is best? Well, the truth is a vast majority of the research shows there are no real differences between these principles when looking specifically at measures of strength across a number of different movements in both the upper and lower body, as long as training volume and intensity is equal for the entire training period. Unfortunately, there is very little literature on muscle gain when comparing these two types of periodisation from this perspective.


So does that mean that neither method is better than the other? Well, not just yet. Many of these studies have been performed on young males with very little training age; it is possible that at different ages and training experience we might find different results. The other issue with many of these studies is that they only assess the effectiveness of LP and UP over a period of a few months.


What is interesting is that in longer studies, UP caused greater increases in strength in the first few weeks, however as the block progressed, LP ‘caught up’ and strength differences became negligible. This isn’t really surprising, as with DUP you would be working at higher intensities earlier in the training block, which is more specific to gaining strength but plateauing quickly, whereas LP will be less specific towards strength in the early phases, building towards optimising strength at the later stages.


I think it is important to note that in order to progress in training, we also have to factor a psychological perspective and that the training style or periodisation method you employ for strength training should be one that prevents you becoming bored, keeps your training fresh and ensures you stay focused, as long as the fundamental cornerstones of the program are met. This is where, to many people, DUP has an advantage, as in each session/week the constantly changing volumes, intensity and progression can be seen across a whole host of repetition schemes, simultaneously keeping things interesting from a psychological perspective. As with diet, whatever training program you use, whatever type of periodisation it employs and how often it changes exercise type, intensity and volume, it will only be effective if it is something you can stick to.


In summary, there appears to be no real difference in strength between using LP and UP methods. However, which program is most successful for you will depend a lot on your own mentality of how you like to train and the effort that you put in to a program. I think whatever training style you use, ‘switching it up’ now and again is going to create a novel stimulus that can help break through training plateaus both from a strength, performance and muscle building perspective, and to reinvigorate passion for training if things become stagnant from a training perspective.


Thanks for reading,

Dr P.