L-Taurine
Taurine is an amino acid like glutamine that is earning more and more respect from bodybuilders and protein scientists.
While taurine generally is the second most abundant amino acid in muscle, in several metabolic conditions, some muscle biologists like Eric Serrano, M.D., have determined that it, not glutamine, is the most voluminous amino represented in striated type 2 muscle fiber! Taurine has several critical functions and can act similarly to creatine in that it expands your cells by helping the muscle cell itself hold more water, increasing cell volume. For a lifter or bodybuilder, this is significant because expanded muscle cells can boost hydration resulting in a higher rate of protein synthesis and bodybuilders will appreciate the increased appearance of muscle fullness.
Additionally, another 'theory' is that taurine preferentially enhances interstitial contractile leverage and this may aid the lifter in handling heavier weights.
Nowadays, you will often find taurine added to creatine or amino acid preparations in bodybuilding supplements for a heightened effect. The best time to consume these combinations might be 30 minutes before training and again immediately after.