Salivary cortisol
Hypothalamic-pituitary-adrenal (HPA) activity was assessed at D0 and D28 of the intervention using salivary CAR. Participants were asked to provide 5 saliva samples in 15-mL Falcon tubes. Samples were collected immediately upon waking and subsequently every 15 min until 1 h post waking (0, 15, 30, 45, and 60 min) in separate Falcon tubes. Saliva samples were delivered at the same time as urine and feces. Saliva samples were allocated in 1.5-mL Eppendorf tubes and stored at –80°C until analysis via commercial ELISA (Biotechne, R&D systems) could be completed.