Len's Star Rating: 7 out of 10. A book that provides the backstory, rationale, and research that supports the X3, a muscle-building variable resistance system.

Len's Star Rating: 6 out of 10. A solid book on improving depressive symptoms through physical exercise.

Len's Star Rating: 9 out of 10. An excellent, approachable book on Ayurvedic medicine and natural remedies for insomnia, obesity and other bodily ailments.