A recent study tested 24 recreationally active male subjects on muscle endurance, power performance and rate of fatigue after supplementing with Betaine.
Subjects were tested 3 times; prior to supplementation, after 7 days of supplementation and after 14 days of supplementation. Each testing period was two days long. On day 1 vertical jump power and bench press throw was assessed to measure power performance. Additionally subjects had to do as many repetitions as possible at 75% of their one repetition max (1-RM). On the second day subjects were performing a Wingate Test to measure anaerobic power.
Results were surprising; no differences occurred in total repetitions performed to exhaustion in the bench press exercise but significant differences were observed in total number of repetitions performed in the squat exercises. In general, no significant change between supplemented and placebo group occurred in peak power, mean power, rate of fatigue and total work.
The authors concluded that Betaine ingestion can significantly improve muscle endurance in lower body workout. Improvements may be seen within one week of supplementation.
Background: Betaine supplementation in animals has shown increased growth and reduced body fat in pigs, it improved recovery in horses and has shown to protect fish moving form varying salinity waters by acting as an osmolite. In humans studies have not been as promising as in animals yet. One study tested treadmill running in heat but failed to report any ergogenic benefit of Betaine in regard to time to exhaustion. Another study tested 14 days Betaine supplementation on strength and power performeance and found no significant changes in repetitions in squat and bench press exercises (muscle endurance) but they found significant changes in the power output measurements. This study is controversial to the recent study by Jay R Hoffman mentioned above.
It is difficult to draw a conclusion of Betaine supplementation yet. More studies have to be done, studies which include maybe even a structured training along with supplementation to see more clearly the effects of Betaine on power and endurance components. So far we can assume that Betaine might have ergogenic potential after consuming it already only for a week.