Complex sentence: Kettlebell swings are an easy exercise to intensify by using a heavier kettlebell, increasing the repetitions and/or sets, or by doing one-armed kettlebell swings.
Split into simpler sentences: Kettlebell swings are an easy exercise to intensify. They can be intensified by using a heavier kettlebell, increasing the repetitions and/or sets, and by doing one-armed kettlebell swings.