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I'm going to be analyzing the ingredients in ASGT, and posting studies to support their use. This'll be a work in progress, as it's tedious, but I enjoy it. 
First off, the stim complex, specifically caffeine:
First off, the stim complex, specifically caffeine:
MENTAL PERFORMANCE
In the same 1992 review (1) it was concluded that “When caffeine is consumed in the range of doses found in many foods, it improves the ability of individuals to perform tasks requiring sustained attention, including automobile driving. In addition, when administered in the same dose range, caffeine increases self-reported alertness and decreases sleepiness”. “Adverse behavioural effects occur when caffeine is consumed in excessive doses or by individuals who are overly sensitive to the substance”.
More recent work has confirmed these conclusions. Thus caffeine increases the processing of new stimuli (2), enhances target detection and response preparation (3) and increases the amount of information processed (4). Such improvements in mental performance are likely to have important implications for the performance of every day tasks. Thus caffeine improved both performance on a driving simulator and during laboratory tests of attention (5). Mental performance declines with age. A cross-sectional study of 890 women and 638 men, mean age 73 years, looked for associations between cognitive function as measured by 12 standardised tests and lifetime or current coffee consumption (6). A higher lifetime coffee consumption in women was significantly associated with better mental performance in six tests. Recently published studies have demonstrated that coffee drinking reduces cognitive decline in both men and women. Van Gelder et al (7), examined whether coffee consumption was associated with 10-year cognitive decline in elderly men. The study participants were 676 healthy men born between 1900 - 1920 from Finland, Italy and the Netherlands. The authors concluded that 'Findings suggest that consuming coffee reduces cognitive decline in elderly men. An inverse and J-shaped association may exist between number of cups of coffee consumed and cognitive decline, with the least cognitive decline for men consuming 3 cups of coffee per day'. Similar findings were reported for women in a study that examined the association between caffeine intake, cognitive decline and dementia in a community based sample of subjects aged 65 years and over(8). The participants were 4,197 women and 2,820 men from a population cohort recruited from three French cities. Cognitive performance, clinical diagnosis of dementia, and caffeine consumption were evaluated at baselineand at 2 and 4 year follow-up. The authors found that the psychostimulant properties of caffeine appeared to reduce cognitive decline in women without dementia, especially at higher ages. Interestingly, unlike Van Gelder, these researchers found no relation between caffeine intake and cognitive decline in the male participants of thier study.
References:
1. Liebermann, H.R. Caffeine. In: Smith, A.P. and Jones, D.M. (Eds.), Handbook of Human Performance, vol. 2. Academic Press, London, pp. 49-72, 1992.
2. Smith, A.P. et al. Physiology and Behavior, 67, 9-17, 1999.
3. Lorist, M.M. and Snel, J. Electroencephalography and Clinical Neurophysiology, 102, 401-413, 1997.
4. Ruijter, J. et al. Journal of Psychophysiology, 13, 37-48, 1999.
5. Brice, C. and Smith, A.P. Human Psychopharmacology, 16, 523-531, 2001.
6. Johnson-Kozlow, M. et al. American Journal of Epidemiology, 156, 842-850, 2002.
7. Van Gelder,B.M. et al, European Journal of Clinical Nutrition, 61, 226-232, 2007.
8. Ritchie, K, et al. Neurology, 69, 2007.
There is evidence that caffeine can improve physical performance. In a study on recreational athletes, the consumption of 6mg/kg body weight of caffeine – roughly 490 mg caffeine for a 180 lb. male, or about five cups of coffee - significantly increased muscle endurance during brief, intense exercise. Prior to a maximum effort run, caffeine consumption of 5 mg/kg body weight – roughly 295 mg caffeine for a 130 lb. female, or about three cups of coffee - resulted in significantly greater anaerobic metabolism and improved athletic performance among recreational runners.5
In addition, a study conducted on cyclists found that consuming 6 mg caffeine per kg body weight (about 355 mg for a 130 lb person, or three to four cups of coffee)improved performance times during a cycling trial, regardless of whether caffeine was ingested one hour before exercise or in a series of doses throughout the trial.6
Researchers made another interesting observation in this study – they found that caffeinated soft drinks could act as a replacement for sports drinks during the last part of an event with no loss of performance. They also found that soft drink consumption produced “enhanced performance” when consumed at the end of tasks. The benefits observed were determined to be largely due to the ingestion of a small amount of caffeine - just 1.5 mg/kg body weight (roughly 90 mg caffeine for a 130 lb person, or about one cup of coffee).7 Other research has also suggested that all types of caffeinated beverages, including soft drinks and sports drinks, are of equal value to cyclists in terms of improved performance during a prolonged task.
Consumption of caffeine has also been shown to improve endurance during physical exercise when consumed before the task.8 One explanation for this is that caffeine may lower the threshold for exercise-induced β-endorphin and cortisol release. These hormones produce the so-called “runner’s high,” which may contribute to the reported caffeine exercise benefits. However, further research must be done to investigate this theory.
Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training. Sea-Air-Land.
Lieberman HR, Tharion WJ, Shukitt-Hale B, Speckman KL, Tulley R.
Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760-5007, USA. [email protected]
Abstract
RATIONALE: When humans are acutely exposed to multiple stressors, cognitive performance is substantially degraded. Few practical strategies are available to sustain performance under such conditions.
OBJECTIVE: This study examined whether moderate doses of caffeine would reduce adverse effects of sleep deprivation and exposure to severe environmental and operational stress on cognitive performance.
METHODS: Volunteers were 68 U.S. Navy Sea-Air-Land (SEAL) trainees, randomly assigned to receive either 100, 200, or 300 mg caffeine or placebo in capsule form after 72 h of sleep deprivation and continuous exposure to other stressors. Cognitive tests administered included scanning visual vigilance, four-choice visual reaction time, a matching-to-sample working memory task and a repeated acquisition test of motor learning and memory. Mood state, marksmanship, and saliva caffeine were also assessed. Testing was conducted 1 and 8 h after treatment.
RESULTS: Sleep deprivation and environmental stress adversely affected performance and mood. Caffeine, in a dose-dependent manner, mitigated many adverse effects of exposure to multiple stressors. Caffeine (200 and 300 mg) significantly improved visual vigilance, choice reaction time, repeated acquisition, self-reported fatigue and sleepiness with the greatest effects on tests of vigilance, reaction time, and alertness. Marksmanship, a task that requires fine motor coordination and steadiness, was not affected by caffeine. The greatest effects of caffeine were present 1 h post-administration, but significant effects persisted for 8 h.
Effects of caffeine on human behavior.
Smith A.
Center for Occupational and Health Psychology, School of Psychology, Cardiff University, UK. [email protected]
Abstract
The literature suggests that the following effects on behavior of adult humans may occur when individuals consume moderate amounts of caffeine. (1) Caffeine increases alertness and reduces fatigue. This may be especially important in low arousal situations (e.g. working at night). (2) Caffeine improves performance on vigilance tasks and simple tasks that require sustained response. Again, these effects are often clearest when alertness is reduced, although there is evidence that benefits may still occur when the person is unimpaired. (3) Effects on more complex tasks are difficult to assess and probably involve interactions between the caffeine and other variables which increase alertness (e.g. personality and time of day). (4) In contrast to the effects of caffeine consumption, withdrawal of caffeine has few effects on performance. There is often an increase in negative mood following withdrawal of caffeine, but such effects may largely reflect the expectancies of the volunteers and the failure to conduct "blind" studies. (5) Regular caffeine usage appears to be beneficial, with higher users having better mental functioning. (6) Most people are very good at controlling their caffeine consumption to maximise the above positive effects. For example, the pattern of consumption over the day shows that caffeine is often consumed to increase alertness. Indeed, many people do not consume much caffeine later in the day since it is important not to be alert when one goes to sleep. In contrast to effects found from normal caffeine intake, there are reports that have demonstrated negative effects when very large amounts are given or sensitive groups (e.g. patients with anxiety disorders) were studied. In this context caffeine has been shown to increase anxiety and impair sleep. There is also some evidence that fine motor control may be impaired as a function of the increase in anxiety. Overall, the global picture that emerges depends on whether one focuses on effects that are likely to be present when caffeine is consumed in moderation by the majority of the population or on the effects found in extreme conditions. The evidence clearly shows that levels of caffeine consumed by most people have largely positive effects on behavior. Excessive consumption can lead to problems, especially in sensitive individuals.
A member of the team, Jason Tallis, tested the effect of caffeine on both the power output and endurance of soleus muscles (lower leg muscle) in mice, under both maximal and sub-maximal activities.
He found that a caffeine dosage of 70 µM enhanced power output by ~6% during both types of activity. This effect in humans is likely to be very similar, according to the researchers.
"70 μM caffeine concentration is the absolute maximum that can normally achieved in the blood plasma of a human, however concentrations of 20-50 μM are not unusual in people with high caffeine intakes," explains Dr James.
Resultant caffeine in blood plasma (70μM maximum) may act at receptors on skeletal muscle causing enhanced force production. Scientists already know that ingestion of caffeine can increase athletic performance by stimulating the central nervous system.
Additionally, 70μM caffeine treatment increased endurance during sub-maximal activity, but significantly reduced endurance during maximal activity.
It goes on, and on, and on. Caffeine also has beneficial effects on age-related mental decline, Parkinsons, and Alheimers, among other interesting things, but those don't relate specifically to ASGT. Suffice it to say, there's a reason caffeine is so widely used.Effect of caffeine on quadriceps muscle pain during acute cycling exercise in low versus high
caffeine consumers.
Gliottoni RC, Meyers JR, Arngrimsson SA, Broglio SP, Motl RW.
Department of Kinesiology and Community Health, University of Illinois, Urbana-Champaign, IL, USA.
This experiment examined the effect of a moderate dose of caffeine on quadriceps muscle pain during a bout of high-intensity cycling in low- versus high-caffeine-consuming males. College-age men who were low (< or =100 mg/day; n = 12) or high (> or =400 mg/day; n = 13) habitual caffeine consumers ingested caffeine (5 mg/kg body weight) or a placebo in a counterbalanced order and 1 hr later completed 30 min of cycle ergometry at 75-77% of peak oxygen consumption. Perceptions of quadriceps muscle pain, as well as oxygen consumption, heart rate, and work rate, were recorded during both bouts of exercise. Caffeine ingestion resulted in a statistically significant and moderate reduction in quadriceps muscle-pain-intensity ratings during the 30-min bout of high-intensity cycle ergometry compared with placebo ingestion in both low (d = -0.42) and high (d = -0.55) caffeine consumers. The results suggest that caffeine ingestion is associated with a moderate hypoalgesic effect during high-intensity cycling in college-age men who are low or high habitual caffeine consumers, but future work should consider better defining and differentiating pain and effort when examining the effects of caffeine during acute exercise.
PMID: 19478340 [PubMed - indexed for MEDLINE]
