The Leg Day Dilemma
It's leg day and you have a decision to make. You're really not feeling it today. You take a look at your workout plan and groan. What do you do?
As a dedicated lifter, you're not going to miss a scheduled workout. So should you stick to the program you've been following and grind through it? Or should you mix things up, choose some different leg exercises, and give it your best?
In science, the first choice involves something called "fixed exercise selection" or FES. You stick to the written workout program. The second choice is called "auto-regulatory exercise selection" or AES. That means you choose exercises, sets, reps, etc. based on how you're feeling that day.
Which is best? Here's what one study found.
Advanced resistance-trained men who could squat 1.75 times their bodyweight and bench 1.3 times their bodyweight were selected for this study. The subjects were split into two groups: fixed exercise selection and auto-regulatory exercise selection.
Both groups lifted weights three times a week for 9 weeks. Each session included an exercise for legs, chest, back, biceps, shoulders, and triceps. There were three exercises available for each body part.
In the fixed exercise selection group, each of the exercises for each body part were used once a week. For example, the exercises for legs were squat, leg press, and leg extension. Day one of each week was squats, day two it was leg presses, and day 3 it was leg extensions.
In the auto-regulatory exercise selection group, the subjects were allowed to choose which one of the three exercises they would do each day, and therefore could use the same exercise for the same body part multiple times a week. While sets and reps were equal across each group, the volume load was not equivalent.
There was a huge increase in volume load in the auto-regulatory group. The 1RM strength gains in the squat and bench press between the two groups lacked any significant differences. Average increase in lean body mass was greater in the auto-regulatory group although it wasn't significant. RPE (rate of perceived exertion) between the two groups were also similar.
What This Means to You
With similar RPE between groups, but a 20% increase in volume load in the auto-regulatory group, it seems that being able to choose exercises in each workout has a large effect on motivation (or some aspect of psychology).
And with average increase in lean body mass being higher in the auto-regulatory group, and a trend towards lean body mass only significantly increasing in the auto-regulatory group, it seems that auto-regulatory exercise selection is a great way to train.
Allow your mental state and physiological readiness dictate the exercises you choose during a workout. The strength gains aren't significantly different from having a structured exercise selection plan. And although not significant, the average increase in lean body mass in the auto-regulatory group was 1.60 kg while the average increase in the fixed exercise group was .98 kg.
So, stay consistent, but don't be afraid to mix up the exercises.
- Rauch, Jacob T, et al. "Auto-Regulated exercise selection training regimen produces small increases in lean body mass and maximal strength adaptations in highly trained individuals." Journal of Strength and Conditioning Research.