James Jackson

James Jackson is a personal trainer who uses his expertise in strength and conditioning to create helpful workout tutorials that show fitness enthusiasts how to build muscle while staying safe in the gym. He draws on the latest sports science data as well as tried and tested training techniques to get the best results for his clients without them having to live in the gym.

Learn how boys and girls can grow taller at 12 years old.

Learn how 10 year olds can get taller and make the most of their upcoming physical development.

Find out the average height for 17 year old males and females in feet.

Find out the average buttocks size for men and women and learn how to measure your glutes.

Learn what the science has to say about the average arm size in males and females.

Discover how to grow taller naturally and achieve your full height potential.

Learn why a normal waist size isn’t necessarily a healthy waist size.

Discover the average height for men in America and in the world.

Find out how much 4 year old boys and girls should weigh and learn how tall they are on average.

Learn the average height for a 12 year old boy and a 12 year old girl.