If your choice of exercises do not enable you to continually lift heavier weights, then your exercises are not improving your strength.
This means that kettlebells, kickboxing, playing with the dumbbells, pilates, yoga, bicycling, jogging, running, swimming, shuffleboard, gardening, balancing on colorful balls while waving chrome weights in the air, treadmilling, elliptical machining, stair-climbing, rock climbing, wood chopping, loading hay on a trailer, snow shoveling, air-squatting, push-upping, and chin-upping, is not strength training.
It may be hard, you may get tired doing it, and it may even make you sore, but it’s not strength training because it cannot make you stronger. Some of these things may require strength, but doing them cannot possibly develop strength since 1) none of them are limited by your absolute strength, and 2) they do not require constantly increasing force production. But all of them benefit from increased strength developed elsewhere.
The Barbell Method is strength training, and since strength benefits everything else, the Barbell Method improves everything else that you can do physically – including every item on the above list.