Stress is a routine part of working life. What is less obvious is how the shape of a working week shows up in cortisol, and what that means for anyone trying to train around it.
The "Weekend Warrior" Cortisol Pattern
Research shows that cortisol levels often rise progressively through the workweek (Monday–Friday) and drop on weekends.
- What that means for planning: If you schedule your hardest sessions for Friday evening, you are placing them on a day when cortisol tends to be highest and mental fatigue is already accumulated.
- One response: Placing active recovery earlier in the week is one way to spread load across days rather than stacking it at the end.
An in-house observation: sound bath and free cortisol
At Summa Labs we wanted to look at this in our own samples, so we ran a small in-house test using our hormone testing kits to measure free cortisol before and after a sound bath session.
One participant took the test. Across that participant's before-and-after samples, free cortisol was 35.6% lower after the session.
This is a single observation, n=1. It is not a study, it does not have a control, and nothing can be generalised from it — not to other people, not to sound baths in general, and not to relaxation practices as a category. We are reporting it because it is what we measured, and because it is the reason we intend to look further.
The science behind cortisol and workweek stress
Separately from our own observation, there is published work on this. A study in PubMed, "Work hours and cortisol variation from non-working to working days", examined how work hours relate to cortisol levels. Researchers analysed 132 day-shift workers, collecting saliva samples at multiple points through the day over a week, including workdays and non-workdays.
Link to article: https://pubmed.ncbi.nlm.nih.gov/22684975/
Key findings:
- Cortisol levels rose significantly on workdays compared with non-working days.
- Longer work hours correlated with higher cortisol concentrations during the workweek.
- No significant differences were found based on gender, age, or workplace within this sample.
That study describes the population it measured. It is consistent with what many people report feeling — that the working week carries a physiological cost, and that stress accumulates across it — but it is one study of 132 day-shift workers, not a statement about everyone.
Reading your own stress response
Workweek stress is one of the loads your body is carrying alongside training. Measuring free cortisol periodically gives you something concrete to read that load against, in your own values, over time. It is one input among many.
Want to test your own cortisol levels? Contact: info@summa.bio
For research and wellness use only. Not for medical or diagnostic purposes.