The triceps are a very well-known muscle group located on the dorsal (back) part of the upper arm. It consists of three heads, hence the name TRIceps - the medial, lateral, and long head.
The primary action of the triceps is extension of the elbow (straightening of the elbow).
The long head also crosses the shoulder (glenohumeral joint) and attaches to the scapula. This not only extends and adducts the shoulder but provides stability to the shoulder helping to minimise displacement of the humerus.
The action at the elbow is what interests lifters the most, particularly in the bench press where the triceps extend the elbow and provide the grunt for a strong lockout.
We can train the triceps as part of the bench press and variations, which you should absolutely be doing. A close grip bench press executed properly for example provides plenty of tricep bias.
Outside of the barbell movements we also use a variety of accessories to specifically target/isolate the triceps.
While there are many exercises, our top 3 are:
3⃣ CABLE TRICEP EXTENSIONS
We can introduce variation into these exercises. Some examples are below.
Dips - we can use a weighted belt to add more load or use a dip machine to use less than bodyweight load. Also consider hand position - neutral, prone, wide, or narrow.
Skullcrushers - we can use different bars - a barbell, an ez-curl bar, or a swiss bar. Or, we can make this a unilateral movement by using kettlebells or dumbbells.
Cable triceps - we can change the attachment, we can use one hand, we can even change the angle you perform the movement - across the body, overhead, or down.
Isolating muscle groups are an important part of general prep base building as it allows us to improve lagging areas and incorporate hypertrophy into our training where targetted stress works well.
Accessories like these are typically performed towards the end of the session after your main lifts using a combination of low and high rep, depending on the phase and intent of the training phase.