Use the following components as a guide to create/modify an exercise when targeting strength. To practice, select the appropriate pattern in the Pattern Vault.
Formant: Open / Multiple
An open formant will best target strength. This is due to there being less resistance above the folds, requiring more stability of the laryngeal muscles.
The H feature is an ideal option to target the dimension of strength by having to work against the air pressure. Otherwise, features tend to make it easier to stabilize the folds.
Pattern: Small Intervals / Staccato
The pattern should be a single pitch, or small range of pitches, which requires more stabilization and stamina. Additionally, any staccato action will target strength, as the arytenoid muscles are required to separate and return for each pitch within the pattern.
Volume: Loud / Swell
Doing the exercise loudly or applying a swell in the exercise helps reinforce strength, as both require a great deal of coordination and stability.
The slower the tempo is, the longer the muscles of the larynx have to work.
Any form of cardio will make it difficult to maintain steady vocal fold positions due to the increased air pressure and actions of the exterior muscles.