Fatigue is sometimes a normal experience and part of normal physiology. Energy fluctuations are a feeling that most humans must deal with at one time or another throughout life. Modern day life puts people in situations in which they must continue to press on, even though their body is sending gentle signals it is time to throttle back and take some time to rest and rejuvenate. The human body is quite amazing in its ability to remain functioning at a high level, even in suboptimal circumstances due to redundancies in human physiology. The challenge with this type of lifestyle which so many live is understanding when the body has been pushed too far, when the symptoms of occasional physical and mental fatigue have crossed the threshold, and all, or most, redundant systems have been exhausted and must be addressed with focused evaluation and appropriate support to maintain an individual's health.
Energy level fluctuations are a feeling that most humans must deal with at one time or another. Modern day puts people in situations in which they must continue to press on, even though their body is sending gentle signals it is time to throttle back and take some time to rest and rejuvenate.
Acute fatigue is a completely normal process, which happens to be a protective mechanism, often linked to a single cause. Identify the cause, whether it be diet, exercise, sleep, or stress, modify the factor, and the fatigue should ameliorate fairly rapidly.1 A sprint causes acute fatigue. Recovering is the answer. The real issue at hand is to determine when the fatigue one feels is not the protective, acute fatigue, which essentially is telling someone to take a short break, and providing more intensive support to, at times, overlooked aspects within the body which help to regulate and provide energy for the body.
Underlying causes of fatigue may include hypothalamic-pituitary-axis (HPA) function, autonomic nervous system health, immune health,2 and mitochondrial health. The HPA axis aids in the body's ability to adapt to a variety of stressors. As stressors on the body increase, supporting the appropriate function of the associated signaling pathways is an essential component of maintaining healthy energy levels.3 Healthy function of the autonomic nervous system is also an important component to exhibiting healthy energy levels and early studies have demonstrated an association between blood pressure, orthostatic intolerance, and fatigue.4
Mitochondria, affectionately known as the powerhouse of the cell, are an important generator of adenosine triphosphate (ATP), the human body's currency of energy. Mitochondria, located in essentially every human cell, carry significant importance in supporting the energy needs of the cells they are associated with. Due to this, levels of fatigue, both physical and mental, are tightly connected to the health of mitochondria.5
When evaluating the causes of fatigue, it is important to remember that just because fatigue is present, doesn't mean the body is not operating appropriately. Properly assessing the potential underlying causes of fatigue will aid in providing appropriate support. One must acquire a detailed history as this may reveal poor dietary habits, sleep, or exercise patterns which are resulting in the body to function healthily, as it is sending signals requesting more rest, better food, or some exercise. The task of identifying when fatigue is more than just a simple signal due to a solitary factor is daunting though.
Healthy mitochondria support the energy levels across many systems. Once one sees shifts in mood, a consistent necessity to support immune function, or a higher level of intolerance to the chemicals we are exposed to on a daily basis, it becomes a prudent moment in time to step back and consider providing support of mitochondria.6
Several factors must be considered prior to pursuing a more robust medical evaluation of source of fatigue. The increase in fatigue must be present consistently for several months. Additional factors to consider include:
- Malaise following exertion
- Sleep is no longer refreshing
- Recurrent mental fatigue
- Orthostatic intolerance7
While many become quite concerned with occasional fatigue, one must understand it may be a completely normal response to daily life and the body is just screaming for a period of relief and rejuvenation. It is important to understand the factors which point to need of evaluation and support of the pathways and organelles which are important to providing healthy energy levels. Once you have considered all of the pieces of the puzzle before you, then it becomes far easier to determine to most effective plan.
1. Silverman MN et al. PM R. 2010;2(5):338-46.
2. Raison CL et al. Brain Behav Immun. 2009;23:327–37.
3. Chrousos GP et al. Nat Rev Endocrinol. 2009;5:374–81.
4. Tanaka H et al. Pediatr. 2002;140:412–7.
5. Gorman GS et al. Neuromuscular Disorders. 2015;25(7):563-6.
6. Morris G et al. BMC Med. 2015;13:68.
7. Jason LA et al. Fatigue Biomed Heal Behav. 2015;3(3):127-41.