Managing Allostatic Load
From Energy Constraints to better decisions
An article written by Sophie Herzog
In Part 1, we explored how allostatic load emerges from the accumulation of physical and non-physical stressors, and how it can impact performance and health.
The next step is to understand how this load can be managed. What determines how much stress an athlete can tolerate? And how can performance environments better support adaptation rather than unintentionally overwhelm the system?
The Mystery of Maximal Sustainable Energy Expenditure
Professional endurance athletes are known to train many hours, which is often positively correlated with performance. High training volumes consequently lead to high energy expenditures. It has been speculated that the maximal sustainable energy expenditure is approximately 2.5 x the basal metabolic rate[i], a constraint imposed by our ability to transform energy[ii]. However, case studies of elite performers[iii],[iv], recently documented approaching the ‘upper limits’ of human capability, revealing workloads and carbohydrate intakes that exceed what research deemed possible and optimal.
In a complex system like the human body, we rely on the adaptability of our allostatic systems to make sure that we stay in “balance” even under extreme circumstances. Adequate energy intakes might allow these athletes to become resilient to the higher demands (i.e., workloads), most likely through a combination of 1) metabolic compensation (efficiency-induced resilience)[1], allocating energy to fuel adaptive processes, and 2) by increasing the total energy budget. At the moment, this is still pretty much a blackbox and might even vary depending on the individual case.
In any case, the ability to sustain a much higher workload has certainly contributed to significant performance improvements in recent years. Nevertheless, we have yet to gain a comprehensible understanding of the “costs” of constantly altered regulatory set-points, and potential consequences of energy being allocated away from health- and longevity-promoting functions such as maintenance and repair, growth, reproduction or cognition.
Impact of Nutrition and Hydration
Adequate and high quality nutrition and hydration are essential not just to sustain high workloads but also to manage stress effectively. A balanced diet that provides the necessary macro- and micronutrients supports the body’s energy balance and recovery.
High training volumes lead to high energy expenditure, necessitating high energy intake. A better understanding of nutritional strategies, such as optimizing carbohydrate intake (daily, during training and competition), has played a significant role in enhancing performance and increasing load tolerance in recent years[v]. However, it is important to recognize that simply consuming more and more carbohydrates does not enable athletes to train infinitely more. There will come a point when “more” doesn’t give you any additional performance benefit, as other factors like digestion, absorption or the feeling of fullness might become a constraint. It is also important to note that carbohydrates are not a cure-all for stress stemming from outside of training.
Furthermore, is also crucial to remember that nutrient intake is not the same as nutrient uptake. The body needs time to process food, and the more you train, the less time there is for digestion and absoprtion. However, adaptations to long-term exercise can make our bodies more biochemically efficient. This means, we can probably absorb more of the nutrients we take in and use fuel more efficiently, such as utilizing more fat at lower intensities while maintaining the ability to oxidize carbs at a high rate when needed.
Adequate hydration is equally important for maintaining optimal physiological functions. Additionally, small molecules like antioxidants[vi] and adaptogens[vii] can help mitigate oxidative stress and may enhance the body’s resilience to stress, although high dosage may prevent performance- and health-promoting adaptations[viii].
Given the variability in daily energy expenditure and the challenge of estimating it precisely, it is vital to also listen to the body’s signals of energy deficiency (or surplus) and not wasting energy to fight against your “natural self”. Being aware of your natural physique, the type of athlete you are and your nutritional habits, can help you understand your tendencies and guide your combined approach to training and nutrition. Hereby, athletes can also benefit from working with nutritionists to create individualized plans that cater to their specific needs, considering their training demands, natural physique, past and current eating behaviors and overall lifestyle. Certainly, however, adequate nutritional input and high quality foods can be a game changer and enhance the capacity to handle more stress (mental and physical) and are therefore an important factor in performance improvement and sustainability.
The Role of Technology in Monitoring Allostatic Load
Advances in wearable technology have revolutionized the way athletes monitor their physiological states. Devices that measure resting heart rate, heart rate variability, breathing rates and sleep duration/”quality” enable athletes and coaches to make more informed decisions about training and recovery. Moreover, the integration of big data and machine learning increasingly allows to get predictive analytics, potentially helping to identify early signs of allostatic overload or underperformance, enabling proactive stress management and preventing long-term detrimental effects.
However, we are still lacking direct measurements that indicate overall stress load. While a lot of wearable devices use algorithms to predict “stress levels” using a variety of data inputs, these are not direct measurements. You can’t prick your finger or spit into a tube and get a holistic assessment of your stress levels. But even if we could, for instance, measure biomarkers like hormones in real-time, they are most likely only facilitators and not the reason of chronic effects.
Perhaps in the (near) future we will be able to measure stress-induced (e.g., neurotransmitter-related) brain changes, gain real-time insight on neurogenesis or neurodegeneration, or measure cellular energy fluxes which will provide a more direct understanding? Methodologies like electroencephalography (EEG) have already been used to suggest that exhaustive exercise temporarily reduces brain network efficiency and using EEG for resting state network assessments could be one way to facilitate the evaluation of readiness and efficiency of the central nervous system in different training situations.[ix] However, it remains speculation whether these assessments are on the same temporal scale than our thoughts, perceptions and feelings or whether we can only ever measure “delayed allostatic load”.
Cultural Factors and Gender Differences
Cultural and gender differences can also significantly influence how athletes experience and manage stress. Some athletes might naturally have more relaxed dispositions, which can buffer the impact of stress, while others have to be very conscious that the energy they spend on mental stress doesn’t cause physical shutdowns.
Additionally, hormonal variations can influence stress responses and recovery, with women potentially experiencing different stress impacts (and energy modulations) due to menstrual cycles. Social expectations and pressures can also vary widely across cultures, affecting how athletes perceive and cope with stress. With the current use of smartphones and social media, it is also becoming increasingly important that athletes are taught how to properly “switch off” from an early age. Hereby, educational programs that teach athletes about stress management and recovery can be beneficial, helping them to develop strategies to balance their training with other life demands.
Coping Strategies to manage Allostatic Load
Evolutionarily speaking, we’re built to save energy. We naturally gravitate toward things that recharge us and shy away from anything that drains us: it’s our body’s way of keeping the “cost of living” low. To manage stress effectively, we need to tap into that instinct by becoming more aware of where our energy actually goes versus where we want it to go.
The goal is to spend your energy on purpose, focusing on activities that actually help you recover or increase your capacity for stress. In the end, letting go of the need to be perfect doesn’t just lower your stress; it makes you more resilient and a lot healthier in the long run.
Useful strategies to manage allostatic load include:
Low-stress physical activity: Engaging in activities like walking or hiking in nature, technical/skill sessions, or light gym and plyometric sessions without focusing too much on data or metrics can help to stay active while reducing stress.
Support Systems and Human connection: Seeking support from a sports psychologist, coaches, friends and family can help manage stress. Good coaches are able to monitor and manage athletes’ stress and recovery. Social connections can help to to distract yourself and remind you that there are also other things in life.
Mindfulness and Relaxation Techniques: Practicing mindfulness, meditation, and biofeedback techniques can reduce anxiety levels.
Balanced Lifestyle: High-quality sleep, adequate rest, natural light exposure, good nutrition, and time for friends, joyful activities and relaxation to maintain overall well-being.
Goal Setting: Setting realistic, achievable goals to maintain motivation and a sense of accomplishment.
Positive Self-Talk: Encouraging a positive mindset and focusing on strengths and past successes.
Conclusion
Understanding and managing allostatic load is not just a matter of optimizing performance in the short term – it is about safeguarding the system that makes performance possible in the first place.
While physical load is increasingly well quantified, the psychological and social components of stress remain largely unmeasured. Yet, they draw from the same finite energy budget and may ultimately determine how much load an athlete can truly tolerate.
This creates a critical blind spot: we tend to manage what we can measure, while underestimating what we cannot.
Moving forward, performance management must shift from a focus on isolated variables to a more integrated understanding of total load. This requires combining data, context, and human judgement – not replacing one with the other.
At its core, this is not just about pushing limits, but about understanding them. Because sustainable performance is not built on maximising load, but on aligning it with the system’s capacity to adapt.
[1] Not just metabolic efficiency, also biochemical and mechanical efficiency.
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[ii] Yang X, Heinemann M, Howard J, Huber G, Iyer-Biswas S, Le Treut G, Lynch M, Montooth KL, Needleman DJ, Pigolotti S, et al. , 2021. Physical bioenergetics: energy fluxes, budgets, and constraints in cells. Proc. Natl. Acad. Sci. USA 118.
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[iv] Christensen PM. Aerobic Energy Turnover and Exercise Economy Profile During Race Simulation in a World-Record-Breaking Male Full-Distance Triathlete. Int J Sports Physiol Perform. 2024 Nov 14;20(1):161-167. doi: 10.1123/ijspp.2024-0221. PMID: 39541954.
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[vii] https://www.trainingpeaks.com/blog/adaptogens-for-athletes/
[viii] Li S, Fasipe B, Laher I. Potential harms of supplementation with high doses of antioxidants in athletes. J Exerc Sci Fit. 2022 Oct;20(4):269-275. doi: 10.1016/j.jesf.2022.06.001. Epub 2022 Jun 11. PMID: 35812825; PMCID: PMC9241084.
[ix] Büchel D, Sandbakk Ø, Baumeister J. Exploring intensity-dependent modulations in EEG resting-state network efficiency induced by exercise. Eur J Appl Physiol. 2021 Sep;121(9):2423-2435. doi: 10.1007/s00421-021-04712-6. Epub 2021 May 18. PMID: 34003363; PMCID: PMC8357751.
Really good one! 🔝