The body constantly works to maintain homeostasis, or a state of internal balance. (source) Anything that can potentially disrupt this balance, whether physical or psychological, real or perceived, is a stressor. (source) Stress load represents the cumulative effect of these stressors on the body’s internal balance. The body’s ability to effectively manage this load plays a key role in performance.
Various physiological and cognitive processes are triggered in response to stressors. This attempt to maintain homeostatic balance is part of a larger concept termed “Generalized Adaption Syndrome,” or GAS. GAS consists of three major phases: the Alarm Phase, Resistance Phase, and Exhaustion phase. (source)
The Alarm Phase refers to the recognition of a stressor and subsequent physiological and cognitive responses to this stressor. (source) During this phase, drastic changes in endocrine, cardiovascular, and neurological systems mediate the “flight or fight” response. (source)
The Resistance Phase begins when the body attempts to counteract the physiological response triggered during the alarm phase and return to homeostasis. (source) Often, this process is followed by a recovery phase and adaptation. (source, source)
The Exhaustion Phase occurs when the body’s continued attempts throughout the resistance phase to return to a homeostatic state fail. (source) In this stage, the body exhausts the resources used to recover from the initial Alarm Phase, often leading to overstrained systems and maladaptive responses.
Stress, both physical and psychological, triggers a variety of physiological responses. Though it can serve as a catalyst for growth and adaptation, when left unregulated, stress can have detrimental effects on performance. By effectively managing stress load, individuals not only can safeguard their mental and physical health, but also enhance their overall performance and growth potential.
Stress affects cognitive and physical performance in various ways. In moderate amounts, it can enhance physiological functions, leading to enhanced performance and driving adaptation. (source, source) When the body cannot recover from stress, performance and adaptation are hindered.
Cognitive function is a cornerstone of optimal performance. While moderate amounts of stress may be beneficial, excessive stress has been shown to hinder memory, learning, and decision-making. (source, source)
Sleep Both chronic and acute stress have been shown to negatively influence sleep performance. (source) These stressors limit the restful and restorative effects of sleep, which can lead to diminished adaptation and recovery and increased feelings of fatigue.
Immune function has a complex relationship with stress. For example, acute stress has been shown to be beneficial for supporting immune function. However, chronic stress suppresses protective immune functions and exacerbates pathological immune responses. (source)
Injury and injury recovery rates have been linked to stress. Individuals reporting higher levels of stress have been shown to exhibit higher injury rates. Stress further complicates injury by hindering recovery rates. (source, source)
Physical performance has been shown to suffer under stressful conditions. Excessive stress load negatively affects maximal muscle contraction, recovery, and markers of aerobic performance. (source, source, source)
Fatigue perception is sensitive to chronic stress. Those who have higher amounts of perceived stress also have been shown to report higher perceived fatigue scores. (source)
Common experiences relating to the management of stress load are found in the table below:
Prioritize fiber-rich foods Foods high in fiber promote gut health by nourishing beneficial bacteria in the digestive system, which positively influences serotonin production. This gut-brain connection helps maintain a balanced mood. (source, source) Recommendation Incorporate fiber-rich foods, like oats, beans, and whole grains, with the target of at least 30 g of fiber per day.
Spend time in nature Exposure to natural settings has been shown to help reduce markers of stress like cortisol. While further research is needed, multiple theories suggest that exposure to natural settings helps overcome mental fatigue and activates the parasympathetic nervous system. (source, source) Recommendation Spend at least 20 minutes outside, preferably in a natural setting, daily.
Supplement with Rhodiola Rosea Rhodiola rosea, a natural adaptogen, has been shown to support healthy stress levels by acting on the adrenal glands, which regulate the body's response to stress. This botanical extract supports adrenal function, enhancing the body's ability to adapt to stressors while supporting overall mental well-being. (source) Recommendation Supplement with at least 100 mg of Rhodiola rosea daily.
Stress affects the body in a multitude of ways and through complex physiological pathways. Moderate amounts of stress can elicit positive cognitive and physical responses that lead to optimal performance. On the other hand, chronic levels of stress can hinder these processes and negatively impact performance. Understanding chronic levels of stress-related biomarkers can help assess overall stress load.
Neural Stress is a measurement that examines the resources available and environment in which neurons are functioning. Depleted resources and harmful environments diminish neurological function, which can lead to extensive negative effects on cognitive and physical performance. (source, source)
Cortisol is considered the “stress hormone.” Chronically high levels can signal excessive exposure to stress. (source) These elevated concentrations can have a negative effect on testosterone, a hormone with regenerative and protective qualities, hindering adaptive processes. (source) Chronically low levels of cortisol can also be a sign of over-stress. This recurring decrease in concentrations can be a sign of adrenal gland overuse and burnout, which can result in hindered performance. (source, source)
Dehydroepiandrosterone sulfate (DHEA-S) is an anabolic hormone with regenerative and adaptive properties. It has been shown that prolonged stress can reduce DHEA-S levels, potentially due to a change in cells in the adrenal cortex and a shift to biosynthesis of corticosteroids, which ensures cortisol production. (source) These decreased concentrations signify overexposure to stress and inability to recover.
Red Blood Cell (RBC) Magnesium helps provide deeper insight into magnesium status. Magnesium plays a vital role in the maintenance of normal cellular and organ function. (source) What's more, decreased levels of magnesium have been shown to be associated with increased stress. (source) Measuring magnesium levels can help give further insight into stress levels.
Homocysteine is an amino acid produced in all cells during cysteine and methionine metabolism (an essential amino acid). It is associated with cardiovascular disease risk and reduced cognitive function. (source, source, source, source) Homocysteine has been shown to respond to stress levels and can give further understanding of stress loads. (source)
