Opioid-induced hyperalgesia is a paradoxical increase in pain sensitivity caused by repeated opioid exposure
For injury recovery, track pain levels (0 to 10 scale), range of motion, and functional capacity
Moreover, muscle biopsies from older athletic participants showed improved mitochondrial respiration compared to age-matched and physically impaired participants 331
One review observed that three populations receiving 3 g a day of glycine 30 minutes to one hour before bedtime over two to four days experienced decreased fatigue and overall sleepiness
Basdevant, Nutritional deficiency after gastric bypass: diagnosis, prevention and treatment, Diabetes & Metabolism, Volume 33, Issue 1, February 2007, Pages 13-24, ISSN 1262-3636, Eussen SM, de Groot LM, Clarke R, et al