There was no difference in muscle growth between changing exercises frequently and using the same workout. There were no differences in genes for muscle growth between the group that changed exercise variables frequently compared to the group that did the same workout.
SHOULD YOU MIX WORKOUTS FOR BETTER FOR MUSCLE GAIN SUMMARY
- There was no difference in muscle growth between changing exercises frequently (i.e., mix workouts) and using the same workout.
- There were no differences in genes for muscle growth between the group that changed exercise variables frequently compared to the group that did the same workout.
As a teenager growing up, my source of information was Muscle and Fitness and Muscular Development magazine for workouts and information. The legendary Joe Weider, who built the fitness empire of bodybuilders, had a series of principles for strength training to build muscle. One of those principles was muscle confusion.
Muscle confusion (i.e., confusing muscles with frequent changes) is the principle that the body adapts to your workout; therefore, you must constantly switch your exercise routine to gain muscle. Change your exercises; muscle groups order (i.e., train lagging body parts first), amount of weight, number of reps, rest periods, sets, etc. The theory was that if you do a different exercise, it confuses the muscles (i.e., shocks your muscles into new growth).
Research has suggested that changing weights, sets, reps, and exercises may activate different muscle fibers contributing to greater muscle growth. (Ogborn & Schoenfeld, 2014) One of the rationales for changing rep ranges with higher and lower rep ranges is to optimally increase both type I (i.e., aerobic) and type II (i.e., anaerobic) fibers. Muscle confusion advocates changing your workout every week; some people change their workout every day.
HOW OFTEN SHOULD I MIX WORKOUTS ROUTINE?
The first example is athletes who use muscle confusion and are jacked! People that do CrossFit change their workout regularly. They change the exercises and sets and reps.
There is the CrossFit workout of the day (i.e., WOD of the day) in which exercises are changed daily. CrossFit workouts often include Olympic lifts such as the clean & jerk, snatch, Olympic clean, etc.
Here is an example of a typical CrossFit Workout https://pin.it/4QL04WC
Many Cross Fit athletes you see look like they can compete in bodybuilding. Many people experience large increases in muscle mass following Cross Fit workouts. (Claudino et al., 2018; Wagener et al., 2020)
ATHLETES WHO DON’T MIX WORKOUTS AND ARE JACKED
Olympic weightlifters perform two exercises in the weight room: the snatch and clean and jerk. Many Olympic lifters perform two-a-day workouts to maximize their technique. Olympic lifters will do power lift variations of the exercise, such as the power clean and jerk, power snatch, push jerk, etc. The typical weight lifter will follow a progressive overload plan which involves increasing the weight while the volume (i.e., set x reps) is gradually reduced.
Weight lifters clearly show signs of muscle growth following a program with very little variation. Studies have shown that lifting heavy or light weights results in similar increases in muscle growth when the volume is similar. (Schoenfeld et al., 2021)
Sample Olympic Lifting program: https://pin.it/4jZxfai
These are two contrasting styles of workouts where CrossFit athletes change workouts regularly, whereas Olympic lifters don’t change their workouts often, but both are jacked! This makes one question, “How often should you change your workout to build muscle?”
HOW OFTEN SHOULD YOU MIX WORKOUTS ?
A 2022 study wanted to examine if changing your workout led to greater increases in muscle growth. The researchers took 20 resistance-trained males and had them train each of their legs with a different training program.
Using the same person but different legs eliminates the large variability between subjects. One leg did the same exercises, and the other leg used a variety of different variables. All the exercises were taken to failure or close to failure for eight weeks.
NO VARIATION LEG: Performed leg press and leg extension but changed nothing. This leg was exercised between 9 to 12 reps, 8 sets (4 sets of leg presses and 4 sets of leg extensions), lifted at a normal tempo, and rested for 2 minutes between sets.
VARIATION LEG: Performed leg press and leg extension but changed everything. 25% of the time, they exercised with high reps (25-30 reps), and 25% of the time, they increased their volume (12 sets total: 6 sets of leg presses and 6 sets of leg extensions), 25% of the time they used eccentric only exercises in with they used 110% of their maximal lifts, and 25% of their time they used a longer rest period of 4 minutes.