I think pretty much everyone who is regularly going to the gym has heard that it is necessary to change workout plans from time to time. Apparently your body (your muscles) gets used to a routine, so it loses its effectiveness. But is this actually true or just a rumour? Is this only applicable to the gym hunks who train to look like Schwarzenegger? Or is it a marketing trick for Personal Trainers to sell their services at regular intervals? Let me tell you what science has to say on this topic.
The Concept of Periodization
When I talk about “changing” a workout regime, I refer to periodization. Periodization is a concept of systematic progression of resistance exercise. In the systematic progression, training variables are changed intentionally. Training variables include sets, repetitions, loads, rest periods between sets and exercises, number of exercises performed, repetition velocity (how fast you are performing repetitions), training frequency (how many times a week you train) and type of contractions (concentric, eccentric, isometric).
Loads and Repetitions
Loads and repetitions have an inverse relationship. The heavier the weight you lift, the fewer repetitions you can do. In general, depending on the desired training outcome, the following zones are targeted: High-intensity training involves few repetitions, whereas low-intensity endurance training requires much higher repetitions (eg, 20-25 RM. RM stands for repetition maximum, i.e. the maximum weight you can lift for 20-25 repetitions. The last repetition should be really really hard).
As a general guideline, these are the loads and repetitions depending on your goal:
Muscular endurance: >12 RM
Muscular hypertrophy: 6-12 RM
Muscular strength: <6 RM
Power: 1-2 RM
(American Council on Exercise Personal Trainer Manual, 2014, p 338)
The Principle of Overload
Volume refers to the number of sets and repetitions you do. Systematic progression is necessary to provide progressive overload of the muscle. A periodized training programme uses this principle of overload. If the training stress is slightly greater than normal, the muscles respond positively to low levels of tissue microtrauma. This small damage causes the neuromuscular system to adapt and muscle remodeling processes lead to larger and stronger muscles. Stress to the muscle must be progressively increased as it becomes capable of producing greater force, power, or endurance.
Research shows that muscular strength increases 72 to 96 hours after an appropriately stressful training session (McLester et al., 2003).
Systematically changing the training variables is more effective for strength and power gains than standardized resistance training plans (Kraemer et al. 2000, Fleck, 1999).
Periodization also helps by adding variation to workouts, thus avoiding boredom or training plateaus.
How these training variables are put together into a workout programme depends on the goal of your workout regimen. The number of sets, repetitions, rest intervals and intensity (the percentage of one repetition maximum) depend on your goal, as described above.
For example, one study investigated the effects of training muscle groups on one day per week using a split-body routine versus training 3 days per week using a total-body routine on muscular adaptations in well-trained men. Results showed significantly greater increases in forearm flexor muscle thickness for the group that trained the whole body compared to the group that did a split routine. No significant differences were noted in maximal strength measures. So the findings suggest a potentially superior hypertrophic benefit to higher weekly resistance training frequencies.
When a strength plateau is reached, it is a good idea to change the exercise. A new exercise requires a new neuromuscular response and motor-unit activation pattern that facilitates a period of progressive strength gains. So for example, once you hit that bench press plateau, change to an incline bench press exercise. Although the muscles worked are the same (pectoralis major, anterior deltoids and triceps), the altered body position requires new motor learning and will enable you to use progressively heavier loads in the first few weeks of training.
However, in order to avoid overtraining, The American Council on Exercise recommends to increase the resistance in gradations of no more than about 5%.
In summary, the concept of periodization improves strength and conditioning in healthy trained and untrained athletes. Exercise intensity is the most important variable for stimulating muscle growth. Variation in training stimuli appears to be vital for increasing maximal strength, and longer periods of higher training frequency may be preferred.
Photo: @chanti_fitography Model: me