Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to train for fighting with isometrics [title] Use proper form for isometric exercises. [step] Proper form is important for all exercises-cardio and strength training combined. However, isometric exercises are somewhat unique and should be performed carefully.

Ending1: [substeps] The following is an example of a proper form that combines isometrics resistance between forward and backwards cuts into the torso strength with low power. The following is a " press-and-pull " exercise: do one kick, two kicks and two hands. Ending2: [substeps] Form is useful for developing correctly characterized attacks, or for those areas where you just still feel nervous. Your helper's core is also important for developing proper form. Ending3: [substeps] For any isometric exercise you need to hold the required position (as these are static exercises). In addition, you need to tense all muscles involved-both the agonist muscles (those that help you hold the position) and the antagonist muscles (the ones that oppose the position). Ending4: [substeps] If you're going to be training with isometrics, if they don't have proper form they'll probably get injured when they're running or being fought over, for example. However, if you find you need a more advanced form, be aware isometrics will want to train stronger forms.

Answer format: ending1/ending2/ending3/ending4