Why Entrepreneurs Feel Exhausted at the Peak of Their Careers

Energy changes during midlife can become particularly noticeable for entrepreneurs whose careers involve sustained cognitive demands, long working hours, and irregular schedules. This article looks at how sleep, stress, mitochondrial function, and everyday behaviour influence energy and recovery, with a focus on practical factors that can be observed and adjusted.

Why entrepreneurs experience changes in energy and recovery during midlife, and how sleep, stress, mitochondria, and lifestyle influence performance

For many entrepreneurs, changes in energy become noticeable during a demanding stage of their careers. The business may be growing, responsibilities may be increasing, and professional experience may have created more opportunities than ever. At the same time, a late night can have a stronger effect on the following day, several intense weeks can require more recovery, and familiar training routines may leave the body feeling tired for longer.

Research on entrepreneurship provides some context for this experience. A 2026 study comparing monozygotic twins in Finland and the United States found a positive association between self-employment and stress after accounting for genetic and shared environmental factors. The researchers also found that long working hours partly explained this relationship.

This makes workload, sleep and recovery useful variables to examine when energy begins to change during midlife. Dr. Dmitry Chebanov, Chief Scientist at Holivita, a science-led longevity platform that integrates genetic interpretation with lifestyle and biomarker data, describes energy as an outcome of several interacting biological systems that respond to both internal and environmental conditions.

How Mitochondria Support Energy

Mitochondria produce most of the adenosine triphosphate, or ATP, used by cells as an energy source. They also participate in cellular signalling, metabolic regulation and quality-control processes.

Research into ageing has identified changes in mitochondrial metabolism and mitochondrial quality-control mechanisms across the lifespan. These changes can affect how cells handle energy and respond to physiological demands.

For someone running a company, the practical relevance becomes clearer when daily demands are considered together. A period of travel, long working hours, disrupted sleep and reduced physical activity can place several demands on the same recovery system at once.

This can also help explain differences between people of the same age. Their biological characteristics, working routines, sleep quality and physical activity can vary considerably, so their experience of energy can follow different patterns.

How Stress Builds During Demanding Work

Entrepreneurial work can involve financial uncertainty, complex decisions, responsibility for employees and long periods of concentrated attention. These demands can extend the working day and make it harder to create a clear boundary between professional and personal time.

The 2026 twin study found an association between self-employment and stress and identified long working hours as one factor contributing to this relationship.

Sleep provides another connection between demanding work and recovery. A study of 122 entrepreneurs found that entrepreneurial stressors were associated with insomnia. The relationship differed between experienced and novice entrepreneurs, with work-home interference playing a role among novice entrepreneurs.

For someone managing a growing company, this makes the duration and frequency of intense work periods worth observing alongside sleep and energy. A particularly demanding week may be manageable when followed by sufficient recovery, while repeated periods of high workload can create a different experience.

What Changes in Sleep After 45

Sleep architecture changes gradually with age. A systematic review and meta-analysis covering 65 studies and 3,577 healthy participants found that total sleep time decreased by approximately 10 minutes per decade, while the proportion of deep N3 sleep decreased by around 2% per decade up to age 60.

These figures describe population averages, so individual experiences vary. Sleep can also be influenced by stress, health, hormonal changes, travel, medication and sleep disorders.

For entrepreneurs, sleep becomes particularly relevant when demanding work is combined with early meetings, late calls or frequent travel. The number of hours spent in bed can remain similar while sleep structure and continuity change, which may affect how restorative the night feels.

Protecting sleep therefore becomes a practical part of managing energy during periods of sustained work. Consistent sleep timing, sufficient time available for sleep and attention to recurring disruptions can all provide useful information when energy starts to change.

What You Can Change After 45

Physical activity remains an important part of maintaining metabolic and mitochondrial health as people age. Regular aerobic activity supports cardiovascular fitness and metabolic function, while resistance training helps preserve muscle mass and strength.

The practical approach can remain straightforward. Regular movement throughout the week provides a more sustainable foundation than relying on occasional intense workouts, particularly during periods when work already places a high demand on recovery.

Working hours are another variable worth monitoring. A WHO and International Labour Organization analysis covering 194 countries estimated that people working at least 55 hours per week had a 35% higher risk of stroke and a 17% higher risk of ischaemic heart disease compared with people working 35 to 40 hours per week.

The analysis estimated that long working hours were associated with 745,000 deaths from stroke and ischaemic heart disease in 2016.

These figures describe the working population as a whole, so they should not be interpreted as evidence that entrepreneurship itself causes these outcomes. They provide a useful reference point for considering how many hours a demanding career requires over long periods.

Sleep, physical activity and workload can therefore become useful variables to track when energy changes. They are measurable, they can change over time, and their relationship with energy can be observed within an individual’s own routine.

How to Track Energy Over Time

A single difficult day provides limited information about a person’s longer-term recovery. A more useful picture emerges when the same variables are recorded repeatedly.

For an entrepreneur, a simple record might include sleep quality, working hours, physical activity, perceived energy and periods of unusually high workload. Reviewing these observations over several weeks can reveal whether certain combinations repeatedly precede lower energy or longer recovery.

For example, a person may notice that energy remains relatively stable during periods of long work when sleep stays consistent, while travel combined with late nights produces a noticeable decline. Another person may see a stronger relationship between reduced physical activity and changes in energy.

The value of tracking comes from observing the individual’s own response. Population research can identify broad relationships, while personal records show how those relationships appear within a particular routine. Holivita’s 12-week Health Diary uses this type of longitudinal approach to organise daily observations of sleep, energy, stress and activity over time.

Managing Energy During the Peak of Your Career

Energy during midlife reflects several biological processes, including mitochondrial function, sleep regulation, stress physiology and metabolic health. These systems continue to respond to everyday conditions, while age, workload and recovery can change the way the body responds to sustained demands.

For entrepreneurs, this is particularly relevant during periods when professional responsibility is high and working hours become difficult to reduce. Understanding the relationship between workload and recovery can provide useful information for managing performance over a longer career.

As Dr. Dmitry Chebanov summarizes: “Human energy metabolism is best understood as an interconnected regulatory system rather than a linear pathway. Genetics helps shape the range within which the body operates, while everyday energy levels emerge from ongoing interactions between mitochondrial function, circadian rhythms, stress regulation, and environmental influences.”

The most practical starting point is to observe the factors that can be measured and adjusted within everyday life. Sleep, working hours, physical activity, nutrition, stress and recovery can be tracked alongside energy to identify recurring relationships.

For someone at the peak of their career, this information can help answer a more useful question: which parts of the current routine support sustained performance, and which ones consistently make recovery harder?

More structured approaches to longitudinal self-observation are explored here: holivita.ai