Q: How do you feel about one-arm and one-leg work? I’ve read that training one side at a time can help you contract more muscle fibers. Is that true?
A: We’ve seen studies that show unilateral work to be better at neuromuscular stimulation and therefore heightened muscle-fiber activation. Our main problem with one-limb exercises is time and energy expenditure.
Working one arm or one leg at a time takes
In other words, if you’re doing concentration curls, you’ll be able to put more into your first set for your right arm; at exhaustion you immediately move to your left arm, and you’re breathing hard and are more drained than when you started your right, so you may be forced to stop the set for your left arm early, missing some key growth fibers.

The energy drain isn’t as noticeable on smaller muscle groups such as biceps or delts as it is on, say, a back exercise like one-arm dumbbell rows. Unfortunately, the one-arm dumbbell row is the best stretch-position exercise for midback. Close-grip cable rows are a close second, but one-arm rows allow the arm to come further across the torso for unmatched midback stretch at the bottom. The problem is you have to rest after each arm because you’ll be huffing and puffing—and that will lengthen the time of your workout.
If you can afford the extra time, concentration curls, one-arm dumbbell rows, one-arm overhead extensions, one-leg leg extensions,
Of course, sometimes there’s no way around using one-arm moves. For example, the only stretch-position exercises for the medial-delt head are one-arm cable laterals and incline one-arm laterals. If you’re using a full-range 3D POF delt assault, one of those one-arm moves is mandatory—dumbbell upright rows (midrange), incline one-arm laterals or one-arm cable laterals (stretch), lateral raises (contracted).
NOTE: The original Positions-of-Flexion mass-training e-book is 3D Muscle Building.

Till next time, train hard—and smart—for BIG results.
—Steve Holman and Jonathan Lawson
www.X-Rep.com
Build MASS with bodyweight training
One way you’re guaranteed to pack on stacks of muscle is through a process called muscle protein synthesis (MPS), which more than doubles 24 hours after an intense workout…
Until recently, MPS was only elevated when trainees would lift 70-90% of their one-rep max…
That’s not only dangerous for your joints, but it also sets you up for high injury risk every time you exercise…
It used to be believed that training with your own bodyweight couldn’t get you the same results as training with your 70-90% one rep max… Until NOW.