This study investigated if the Lightning Process® (LP), a three-day training program, could reduce chronic fatigue in adolescent and young adult cancer survivors.
13 participants who had been treated for sarcoma or Hodgkin lymphoma at the Oslo University Hospital, completed the study.  They completed validated questionnaires at baseline, 3-month, and 6-month follow-ups and semi-structured interviews after the 6-month follow-up.
The results showed significant improvements in fatigue, depression, work and social adjustment and health-related quality of life.
Participants reported feeling more energetic, having better-coping skills, and being able to challenge themselves more.
The authors concluded that the LP shows promise as a treatment for chronic fatigue in cancer survivors, and further research is warranted.

You can find more information about the study here: https://lightningprocess.com/research (3rd item)

Study details:
Does the Lightning Process Training Programme Reduce Chronic Fatigue in Adolescent and Young Adult Cancer Survivors? A Mixed-Methods Pilot Study
Fauske et al. 2021
10.3390/cancers13164076