Taking a week off from lifting? Uridine monophosphate helps you keep your thickness.
Lifters are often told not to worry about muscle loss when they take a few weeks off. Muscle loss is a slower process than we think. However, atrophy from detraining does occur, and it may happen faster than previously thought. Luckily, one substance prevents it: uridine 5'-monophosphate disodium salt, or UMP.
The Study
Researchers took 22 healthy young men and measured their upper-arm thickness with ultrasound imaging at three time points:
- Baseline
- After 6 weeks of lifting
- After a 2-week detraining period (no lifting)
Half supplemented with UMP (a key building block of RNA) and half took a placebo. The researchers aimed to determine whether uridine monophosphate could prevent the loss of muscle thickness during detraining.
What Happened?
The placebo group experienced a 2.4% loss of muscle thickness (on average). However, the men taking uridine monophosphate showed no significant decrease after one week, indicating a statistically significant preservation of muscle thickness, probably related to the modulation of protein turnover pathways.
The Tricky Part
The researchers measured three sites on the upper arm with ultrasound:
- MT70 – This is mostly the biceps belly and peak: the bulk of the anterior upper arm.
- MT50 – The mid-arm (biceps + brachialis).
- MT60 – Upper-mid arm (transition zone, more biceps)
The thickness preservation was observed at the MT70 site, the part you're probably looking at when you flex. Uridine monophosphate didn't noticeably affect the other two sites.
The researchers have a couple of theories. First, their ultrasound method may not have been powerful enough to detect the smaller changes at these sites. Or, second, those areas of the upper arm just may not atrophy as quickly. It was easier to spot the muscle preservation benefits of uridine monophosphate in the faster-shrinking MT70 site.
Also, after two weeks, no significant difference was found between the placebo and uridine monophosphate groups. This gives us a rough timeline. We can surmise that uridine monophosphate prevented muscle thickness loss for at least a week.
How to Use This Info
Lifters and biohackers don't actually take uridine monophosphate to prevent muscle loss during a one-week vacation or when they can't lift for seven days. They take it for its other benefits:
- As a motivation supplement. It increases dopamine levels and boosts mood, among other things.
- As a nootropic or cognitive enhancer. It improves memory, boosts focus, and speeds learning.
- As a pre-workout. Uridine monophosphate contributes to energy metabolism and muscle recovery, boosting training endurance and reducing CNS fatigue.
For those benefits, Biotest included 300 mg of uridine monophosphate in the Igniter (Buy at Amazon) formula, along with other mental and physical performance enhancers, including three ingredients that give lifters bigger, longer-lasting pumps.
But it's good to know that uridine monophosphate also helps you retain most of your muscle thickness after a week of detraining. Call it a sweet bonus benefit.
Reference
- Yamada, Yusuke, et al. "Uridine 5′-Monophosphate Supplementation Attenuates Loss of Muscle Thickness during Short-Term Detraining after Resistance Training in Healthy Young Men: A Randomized, Double-Blind, Placebo-Controlled Trial." Frontiers in Sports and Active Living, vol. 6, 2024, Article 1403215.