Gakic beneficial?
Re: Gakic........maybe better to call it Gimmik.
The 10 or more % gain in strength quoted likely comes from a study in Med Sci Sports Exerc. 2000 Dec;32(12):2102-8 entitled "High-intensity dynamic human muscle performance enhanced by a metabolic intervention". They found Overall gain in total muscle work attributable to GAKIC was 10.5 +/- 0.8% greater than control, sustained for at least 15 min. After 24 h, both GAKIC and control concentric forces returned to the same absolute values (P > 0.05). They concluded "compared with isocaloric carbohydrate, oral GAKIC treatment increased muscle torque and work sustained during intense acute anaerobic dynamic exercise; additionally, it increased overall muscle performance by delaying muscle fatigue during the early phases of anaerobic dynamic exercise". Take note though that there were only 13 patients in this study and that strength returned to being not-different from control at 24 hrs. Suggests to me no real muscle change or gain. I wonder if caffeine or ephedrine would give you a similar short-term boost in exertion with similar "strength gains". Hard to prove much with only 13 patients. Surprised it got published. You always have to look at who sponsors these papers too and if there is financial incentive to show a benefit. Also, remember that negative (no benefit) studies are less likely to get published, thus may also bias positive reports.
Heavy's quote / ref is from: Medicine & Science in Sports & Exercise: Volume 35(5) Supplement 1 May 2003 p S268
THE EFFECTS OF GLYCINE-ARGINE-Á-KETOISOCAPROIC ACID ON REPEATED SETS OF ANAEROBIC CYCLING. They used only 10 subjects and found no benefit. Very interestingly, they re-worked their data (from their whopping sample of 10 patients) and published the following in 2004: Med Sci Sports Exerc. 2004 Apr;36(4):583-7 Glycine-arginine-alpha-ketoisocaproic acid improves performance of repeated cycling sprints that concluded "these data support an ergogenic effect of GAKIC for attenuating the decline in mean power during repeated bouts of supramaximal exercise". Nothing like re-working the numbers to make them say what you want them to say. What a bunch of bullshit!!
As they say, if it sounds too good to be true, it probably is. This is almost certainly one of those cases. Many, many supplements are a total waste of cash and risk side effects. I would suggest thoroughly reviewing them before use. Even things that have a huge following and market (like creatine) have had many, many papers written on them to show a modest benefit. But at least the data is there and you can make some concrete decisions about use. Compare that with a few small and poor studies in one type of setting (cycling sprints) on record for things like Gakic and I think you'd be crazy to waste your time and money on it until far more research has been done. Train hard, eat right, and sleep....that's gonna give you more benefit than 99% of the supplements out there. If you really need the gains, go with something undisputed, like AAS. Even in modest doses, you'd be likely to see more gains than the highest doses of questionable supplements. Not that I'm encouraging AAS use
That's my 2 cents