Neil Gresham is a British climber and trainer who's been training people for about 20 years now. He's the training columnist at both Climbing and Rock & Ice magazines, and has written extensively on the topic.

At 44, he's still pushing his limits on sport climbs (14b last year), ice climbs, and deep water solos, among other types of climbing. Although he has no formal background in training (I'm finding that to be irrelevant in these interviews), he's studied the literature on climbing training and other related sports. But most of all, he's debatably one of the most experienced climbing trainers out there, having been doing this pretty full time since the 1990's. 

He also wrote an interesting article recently about his ketogenic diet that's made a huge difference in his climbing and body composition, which I responded to with my own podcast episode about the diet. We talk about his experience with keto and exactly what he eats on it. 

• Case study of 5.10/11 climber trying to break into the next level

• Neil Gresham's website