CoQ10 for fatigue due to physical exertion
Anti-fatigue effects of coenzyme Q10 during physical fatigue.
Nutrition. 2008 April. Department of Physiology, Osaka City University Graduate School of Medicine, Osaka, Japan.
This study examined the effects of coenzyme Q10 administration on physical fatigue. In a double-blinded, placebo-controlled, three crossover design, 17 healthy volunteers were randomized to oral coenzyme Q10 (100 or 300 mg/d) or placebo administration for 8 d. As a fatigue-inducing physical task, subjects performed workload trials on a bicycle ergometer at fixed workloads twice for 2 h and then rested for 4 h. Oral administration of coenzyme Q10 improved subjective fatigue sensation and physical performance during fatigue-inducing workload trials and might prevent unfavorable conditions as a result of physical fatigue.

Caffeine and fatigue - does caffeine work for fatigue?
Effects of oral administration of caffeine and D-ribose on mental fatigue.
Nutrition. 2008 March. Ataka S, Tanaka M, Nozaki S, Mizuma H, Mizuno K, Tahara T, Sugino T, Shirai T, Kajimoto Y, Kuratsune H, Kajimoto O, Watanabe Y. Department of Physiology, Osaka City University Graduate School of Medicine, Osaka, Japan.
We examined the effects of administering two different candidate antifatigue substances, caffeine and D-ribose, on mental fatigue. In a double-blinded, placebo-controlled, three-way crossover design, 17 healthy volunteers were randomized to oral caffeine (200 mg/d), D-ribose (2000 mg/d), or placebo for 8 d. As fatigue-inducing mental tasks, subjects performed a 30-min Uchida-Kraepelin psychodiagnostic test and a 30-min advanced trail-making test on four occasions. During the tasks, the task performance of the caffeine group was better than that of the placebo group. However, after the fatigue-inducing tasks, although subjective perception of fatigue, motivation, or sleepiness was not significantly different, plasma branched-chain amino acid levels in the caffeine group were lower than those of the placebo group. Administration of D-ribose had no effect. Because plasma branched-chain amino acid levels are decreased by mental fatigue, these results suggest that administration of caffeine improved task performance through the enhancement of central nervous system activity without increasing the sensation of fatigue. However, further decreases in branched-chain amino acid levels indicate that caffeine might promote deeper fatigue than placebo.

Adrenal Fatigue
Many people who have fatigue think it may be due to the adrenal glands. However, fatigue due to adrenal exhaustion is not as common as other reasons for fatigue, particularly lack of exercise, poor diet, lack of adequate sleep, anemia, or other medical conditions. Depression is another common cause of fatigue, much more common than adrenal causes.

Are some cases of fatigue genetic?
Disabling fatigue in children is not simply a symptom of depression, but appears to be an illness in its own right -- one that may be inherited. Dr. Tom A. Fowler of Cardiff University in Wales performed a twin study to investigate environmental and genetic influences on both conditions. Twin studies allow researchers to distinguish between the effects of environment and genes. While identical twins have the same environment and genes, fraternal twins share an environment but only half of one another's genetic material. So identical twins would be more likely to share conditions with a heavy genetic influence. The researchers looked at 2,398 pairs of twins between the ages of 8 and 17. Fatigue was considered disabling if it interfered with at least one aspect of school, leisure activities or relationships with family or peers, and if it required the child to rest for at least an hour daily. Fatigue was classified as short term if it lasted longer than one week, and long-term if it lasted more than a month. Both short- and long-term fatigue appeared to have genetic roots, the researchers found, while the environmental influence for short-term fatigue was stronger than the familial influence. British Journal of Psychiatry, September 2006.

Fatigue Research Update
L carnitine administration in elderly subjects with rapid muscle fatigue: effect on body composition, lipid profile and fatigue.
Drugs Aging. 2003;20(10):761-7.
L carnitine is an important contributor to cellular energy metabolism. This study aims to evaluate the effects of carnitine supplementation on body composition, lipid profile and fatigue in elderly subjects with rapid muscle fatigue. METHOD: This was a placebo-controlled, randomised, double-blind, two-phase study. Eighty-four elderly subjects with onset of fatigue following slight physical activity were recruited to the study. Before the 30-day treatment phase, subjects were randomly assigned to two groups (matched for male/female ratio, age and body mass index). One group received carnitine 2g twice daily (n = 42) and the other placebo (n = 42). Efficacy measures included changes in total fat mass, total muscle mass, serum triglyceride, total cholesterol, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), apolipoprotein (apo)A1, and apoB levels. The Wessely and Powell scale was used to evaluate physical and mental fatigue. Subjects were assessed at the beginning and end of the study period. RESULTS: At the end of the study, compared with placebo, the carnitine-treated patients showed significant improvements in the following parameters: total fat mass, total muscle mass, total cholesterol, LDL-C, HDL-C, triglycerides, apoA1, and apoB. Wessely and Powell scores decreased significantly by 40% (physical fatigue) and 45% (mental fatigue) in subjects taking carnitine, compared with 11% and 8%, respectively, in the placebo group. No adverse events were reported in any treatment group. CONCLUSION: Administration of carnitine to healthy elderly subjects resulted in a reduction of total fat mass, an increase of total muscle mass, and appeared to exert a favourable effect on fatigue and serum lipids.

Mechanisms underlying fatigue: a voxel-based morphometric study of chronic fatigue syndrome.
BMC Neurol. 2004 Oct 04;4(1):14.
Fatigue is a crucial sensation that triggers rest, yet its underlying neuronal mechanisms remain unclear. Intense long-term fatigue is a symptom of chronic fatigue syndrome, which is used as a model to study the mechanisms underlying fatigue. Using magnetic resonance imaging, we conducted voxel-based morphometry of 16 patients and 49 age-matched healthy control subjects. We found that patients with chronic fatigue syndrome had reduced gray-matter volume in the bilateral prefrontal cortex. Within these areas, the volume reduction in the right prefrontal cortex paralleled the severity of the fatigue of the subjects. These results are consistent with previous reports of an abnormal distribution of acetyl-L-carnitine uptake, which is one of the biochemical markers of chronic fatigue syndrome, in the prefrontal cortex. Thus, the prefrontal cortex might be an important element of the neural system that regulates sensations of fatigue.

The many faces of fatigue in major depressive disorder.
nt J Neuropsychopharmacol. 2004 Oct 14:1-13
Fatigue is a common complaint in the community and medical care settings. Different studies show a high comorbidity between fatigue and depressive disorder. Furthermore, fatigue is an important somatic symptom of depressive disorder and one of the main depressive presentations in primary-care medicine. Fatigue shows a slow response to antidepressant treatment and psychotherapy. Improved work performance is strongly correlated to improvement in energy. However, the assessment and treatment of fatigue in depressive disorder remains understudied. Different definitions of fatigue in depressive disorder are applied in DSM-IV and ICD-10, and depression rating scales all show a different coverage of this core depressive symptom, thereby hampering scientific research. Serotonin, norepinephrine, dopamine and histamine mediate symptoms of fatigue in depressive disorder. Although few data address the effect of antidepressants or augmentation strategies on fatigue-related symptoms, there is a pharmacological rationale for using antidepressant monotherapies.

Anti-fatigue effect of fresh royal jelly in mice.
J Nutr Sci Vitaminol (Tokyo). 2001 Dec;47(6):394-401.
We investigated the anti-fatigue effect of royal jelly, which had been stored at -20 degrees C from immediately after collection, in male Std ddY mice. The mice were accustomed to swimming in an adjustable-current swimming pool, then subjected to forced swimming five times during 2 wk, and the total swimming period until exhaustion was measured. They were separated into three groups with equal swimming capacity, which were administered royal jelly, royal jelly stored at 40 degrees C for 7 d (40-7d royal jelly), or the control solution including casein, cornstarch, and soybean oil before swimming. All mice were forced to swim for 15 min once; then the maximum swimming time to fatigue was measured after a rest period. The swimming endurance of the royal jelly group significantly increased compared with those of the other groups. The mice in the royal jelly group showed significantly decreased accumulation of serum lactate and serum ammonia and decreased depletion of muscle glycogen after swimming compared with the other groups, whereas there was no significant difference between the 40-7d RJ group and the control group in these parameters after swimming. A quantitative analysis of constituents in royal jelly showed that 5 7-kDa protein, which we previously identified as a possible freshness marker of royal jelly, was specifically degraded in royal jelly stored at 40 degrees C for 7 d, whereas the contents of various vitamins, 10-hydroxy-2-decenoic acid, and other fatty acids in RJ were unchanged. These findings suggest that royal jelly can ameliorate the physical fatigue after exercise, and this anti-fatigue effect of royal jelly in mice seems to be associated with the freshness of RJ, possibly with the content of 5 7-kDa protein.

Fatigue supplement emails
Q. I'm currently deployed in Iraq and was browsing on your website during some down time. I'm interested in one or two of your Energy and Fatigue supplement products that could really be of use to me over here.
   A. As far as anti fatigue supplements, I would mention a few:  
Acetyl-carnitine which has energy and mental alertness
Carnitine which has mostly physical energy and less mental
SAM-e which has energy and mood elevation 
B-Complex and pantothenic acid are great options.
Ginseng, Rhodiola, Suma, and Maca are good herbs for this.