Kettlebells and resistance training
Kettlebell is a very heavy solid cast iron weight in the shape of a ball with a handle on top. Despite its simple design, the kettlebell became very popular in the US and soon became a key piece of equipment for many strength / strong man training routines.
Originally the kettlebell was a fixed weight with various different weights so you'd have a collection of kettlebells to train, however more recently manufactures have became to make adjustable weights.
The kettlebell can be used to train the entire body and often used with 4 main compound lifts. The Kettlebell Swing, the kettlebell snatch, the kettlebell jerk and the kettlebell power clean squat thrust.
Kettlebells are a cheap piece of equipment which can be used to strength train the entire body. Try to buy kettlebells local to you as delivery charges can often make the price less viable.