To get right to
 the point, linear periodization (LP) starts with a training volume that is
 high while using lighter loads, and as training progresses through specific mesocycles, training volume decreases while training
 loads increase.
 With nonlinear periodization (NLP) you change the volume and weight loads from day to day, usually in an undulating pattern. Charles Poliquin
 was one of the first to propose this method of training.(1) As time went on it took on the name “daily undulating periodization.”

A recent study examined the effects of 12 weeks of training using either an LP program or an NLP program on strength and muscle size.(2) Of most importance here are the two periodized routines they chose. Here’s what they looked like:

Training was done twice per week for a total of 24 workouts in 12 weeks. The subjects, volunteers from the Brazilian Navy, were divided into three groups, with 11 in the NLP group, 10 in the LP group, and 9 controls (no training). Weight loads were selected by testing each participant’s rep max for each rep range.

Surprisingly, after 12 weeks, neither group achieved significant increases in muscle size. 
Twelve weeks is plenty of time to see measurable growth in untrained subjects, so this is one big weakness with this study. It did indicate, however, that the NLP group achieved a statistically significant difference in size compared with the control group. The LP did not.

The take-home message is that, although no significant increases in size were produced using either routine, there might be something to performing frequent high-rep work when trying to put on size. It appears from this and previous, more effective, protocols that when you remove the high-rep, burning sets from low-rep phases of training, the growth stimulus is likely to be compromised.

Erin Stern
References: 1. Poliquin, C., Natl Strength Cond Assoc., 10: 34–39, 1988. 2. Simão R., et al, J Strength Cond Res., 2012 May;26(5):1389-95.