A study on muscle growth and strength gains
Here’s a recap on a 2016 study that shows you can put on muscle faster than typically thought and that initial strength gains from starting a workout program may not be coming from just neural adaptations (e.g. increases in muscle fibre recruitment).
In this study published in the journal, Human Movement Science, researchers split 47 untrained women into three groups. One group served as the control so they didn’t have to do much. The other two groups engaged in a weight-training program where they worked out twice a week for 4 weeks. They performed full squats and conventional deadlifts for each workout. The difference between groups was that one had a lower training volume consisting of 2 sets of 5 reps for each exercise. While the other group performed 4 sets of 5 reps for each exercise.
Before, during and after the 4 weeks, the researchers measured the subject’s leg lean mass as well as the muscle thickness of the vastus lateralis and rectus femoris (two of the muscles in the quadriceps). They also measured muscle fibre recruitment during isometric contraction of the quadriceps.
What the researchers found was that the two groups who weight trained showed significant gains in leg lean mass and the muscle thickness of the vastus lateralis. There wasn’t much difference in the muscle thickness of the rectus femoris. They also found that the subjects had to increase their loads on both exercises for each training session. So they got stronger. Additionally (and surprisingly), they did not see any significant changes in muscle fibre recruitment.
Therefore, while initial gains in strength from starting a weight-training program are typically thought to be from neural adaptations and that muscle hypertrophy “kicks in” later, this study shows that this might not be the case. While this is just one study and more studies should be conducted to further shed the light on the subject, it’s interesting to see that muscle can grow significantly in a matter of weeks.
For more information:
Stock, MS et al. (2016) Evidence of muscular adaptations within four weeks of barbell training in women. Hum Mov Sci. Feb;45:7-22