Different pushup variations can have different effects. Find out what muscles diamond pushups work and what areas will likely experience growth.
First of all, diamond pushups mainly work your triceps (back upper arms), front deltoids (shoulder), and to some extent pectoral muscles (chest).
You should expect the most growth and strength increases in your triceps and potentially front deltoids. These two muscle groups will likely fatigue before your chest had a good workout.
Compared to regular pushups, the diamond variation works your triceps and front deltoids harder and your chest muscles less.
Whether this is a benefit of diamond pushups to you depends on your personal situation and training goals.
Primary muscles worked with diamond pushups
Diamond pushups are compound tricep exercises which means they do not only work these muscles but a variety of other ones to some extent.
At the same time, there will still be a few of these muscles that have to move the most weight compared to their relative strengths.
In diamond pushups, you mainly work your triceps (back upper arm), front deltoids (main shoulder muscle), and to some extent chest.
Of these, most people will find that their triceps fatigue first when doing diamond pushups.
Your triceps are the muscles at the back of your arm. These are responsible for stretching your arms.
This movement is not the only one that pushes you up in the diamond pushup but it is a big part of the exercise. Additionally, the triceps are not the strongest muscles you have.
Front deltoids (shoulders)
The deltoids have three parts that are responsible for different upper arm movements.
In pike pushups, the front deltoids will be the main muscle head in action. When standing up, this part is responsible for shoulder flexion aka moving your upper arm forward and upward.
The front deltoids help the triceps a lot in “stretching” your arm by pulling the upper part down in relation to your shoulders.
While it is true that the diamond pushup is a variation that focuses more on the triceps and front deltoids, this exercise still works your pectoral (chest) muscles to some extent.
You do need to keep one potential downside in mind. It is very possible that your tricep muscles fatigue before your chest muscles had a good workout when doing diamond pushups.
In turn, it is fair to say that diamond pushups are not that good for training chest muscles.
Secondary muscles worked with diamond pushups
The muscles above will typically have the hardest time but you also use a variety of other ones.
More specifically, some of the secondary muscles diamond pushups work include your side deltoids, abs, quadriceps, glutes, and to some extent obliques.
You should not really expect any growth or strength progress in these areas but in theory, the endurance in these muscles could improve slightly.
Do decline diamond pushups work different muscles?
Similar to regular pushups, you can do the diamond variation in decline. This means with your feet on an elevated surface.
Decline diamond pushups work similar muscles but in different ratios.
You will focus more on the front deltoids and less on the chest, ab, quadricep, and glute muscles.
Additionally, because you raise your feet, more of your body weight rests on your arms in decline diamond pushups. In turn, your front deltoids and triceps will have to work harder.
At the same time, the number of diamond pushups you should do per workout for muscle growth is still the same. It will just become harder to hit the ranges.
Muscles worked diamond pushups vs regular pushups
One study measured the difference in muscle activity between narrow grip (50%), neutral grip/shoulder width (100%), and wide grip (150%) in a wide variety of muscles (1).
They measured that a neutral grip pushup engaged the middle deltoid shoulder muscle, serratus anterior (surface upper ribs), and latissimus dorsi (middle to lower back) more than narrow grip pushups.
Additionally, narrow grip pushups engaged the pectoralis minor (small upper chest muscle), pectoralis major (big chest muscle), biceps brachii, triceps brachii (back upper arm), and infraspinatus (small muscle at the back of your shoulder) more than neutral grip pushups.
Diamond pushups involve an even narrower grip than the one used in the study but the differences should be similar.
It may be surprising that the narrow grip pushup engaged the chest muscles to a larger extent. Wider grip pushups tend to be considered better for these muscles.
However, how much a certain type of pushup engages a muscle is not the only important factor.
For example, some people are not able to do diamond pushups because they are too hard for their triceps.
Diamond pushups are so hard because tricep muscles are generally weaker than your chest muscles.
Since you use the same weight in regular pushups vs diamond pushups (your body weight), it is logical that you can do fewer diamond pushups.
Even if you are able to do diamond pushups for a few repetitions, your triceps may fatigue before your chest muscles had a good workout.
In turn, this variation would not be good for growing and strengthening your chest.
Muscles worked diamond pushups vs dips
Dips are an exercise where you put your hands on two horizontal bars in the air, lower yourself, and push yourself back up.
The issue when comparing this exercise to diamond pushups is that you can do dips in a variety of ways.
For example, you could theoretically keep your upper body vertical. With this technique, dips would basically be a tricep isolation exercise.
On the flip side, you can also do dips with a wide grip and your upper body tilted forward. This will work your chest, front deltoids, and triceps to nice extents.
If you would take all possible dip variations, they would typically work the chest muscles a bit more than diamond pushups. Both exercises will engage your triceps and front deltoids a lot too.