I have been taking a supplement called Cordymax Its a form of the Cordyceps mushroom that grows in the Himalayan meadows and southwestern China. I have seen decreases in my SAC rate but I can't totally contribute the change to the muchroom becuase diving and practice may be also playing a role. I have seen benefits to friends who race bikes with increases in indurance and stamina. Here is some info on the muchroom and its researched effects. If you want more infor feel free to PM me. A New Study The research team behind the development of CordyMax® will be presenting the scientific foundation of their supplement before one of the worlds leading meeting of physiologists. The study sought to evaluate the effects of CordyMax (a mycelial fermentation product of Cordyceps sinensis) on enhancing exercise capability and endurance, and on acting against fatigue in healthy humans. Methodology This was a clinical trial with a double-blind, randomized, placebo controlled design. One hundred thirty one volunteers were participated in this trial. These individuals were healthy, sedentary males and females of age 40-70. The study employed sports physiology methods, measuring exercise capacity, endurance performance, and exercise related metabolic alterations before, in the middle of, and after the 12-week study treatment with CordyMax (3 g/day). Results The researchers found: (1) Maximal exercise Peak volume of oxygen (VO2peak) consumption was increased by 5.5% in CordyMax group (p=0.003), but by only 2.2% in placebo group (NS). This suggests increases in aerobic exercise capacity by CordyMax. The time to VO2peak was increased by 4.1% in CordyMax group (p=0. 047), but no change in placebo group. This suggests increases in physical strength for aerobic exercise by CordyMax. (2) Sub-maximal, endurance exercise The time for 1-mle walk was reduced by 29 sec in CordyMax group (p=0. 05), but slightly increased in placebo group (+19 sec, NS). This suggests enhanced endurance performance by CordyMax. Exercise work output by use of Jeukendrup bike test was increased by 3.1% in CordyMax group (p=0. 033), but fell in placebo group (-4.9%, NS). This suggests enhanced endurance performance by CordyMax. Respiratory Exchange Ratio (RER) was reduced by 2.1% in CordyMax group (p=0. 018), but no change in placebo group. This suggests improvement in exercise metabolism by CordyMax. (3) General conditions Body Weight was reduced by 0.78% in CordyMax group (p=0. 039), but increased by 0.42% in placebo group. This suggests weight control effects of CordyMax. Diastolic blood pressure was reduced by 3.2% in CordyMax group (p=0.045), but no significant changes in placebo group (NS). This suggests BP lowering effects of CordyMax. Conclusion Numerous supplements are introduced to consumers offering only anecdotal evidence that these products are effective and safe. This study provides scientific evidence that CordyMax® is effective in enhancing aerobic exercise capability, endurance exercise performance, and exercise metabolism and alleviating fatigue in healthy humans.