Hello Mairenjie and welcome to the forum.
I agree with Trusylver in stating that your current training regime is lacking, not least in the amount of compound exercises that appear to be absent (those that utilise more than one muscle group). The more compound movements you incorporate, the greater your strength and muscular gains. Examples can include squats, barbell press and lat-pulldown. Moreover, you’re not currently performing any exercises that specifically target the muscles of your back or your shoulders (shoulder shrugs develop the traps, not the three heads of the shoulder). However, since you’re just starting off, don’t feel too bad, as even experienced gym users and personal trainers all started somewhere.
Taking things slightly back to the drawing board, I’d replace the cable chest press with either a barbell or Smith machine press, as the movement recruits your anterior deltoids (front shoulder muscle) and triceps as supporting muscles when lowering the weight towards your chest. The movement also primes the supporting muscles to be worked in isolation, once compound movements have been executed.
Equally, while back exercises chiefly recruit your rhomboids and lats, the movement to create contraction and extension in their fibres also relies upon contraction and extension of your bicep, as a supporting muscle. Again, the action can prime the biceps to be worked in isolation later in a session.
As for the legs, don’t make the mistake of thinking that they don’t need to be exercised. Although you consider that they already possess mass, the mass possessed isn’t exercised muscle. Despite their size, if you push them, you’ll no doubt find that they tire quickly as the fibres don’t have the endurance.
To demonstrate further, I weigh 20KG more than you do, Mairenjie, yet I’ll routinely exercise my quads, hamstrings and calves in order to ensure that they’re sufficiently conditioned to handle middle-distance running.
Moving on, I’d possibly re-evaluate how many shoulder shrugs and bicep curls you currently perform, choosing to incorporate them alongside some of the compound movements I’ve listed above. Remember, compound first, isolation second.
Concerning other points raised, I’d also agree with Trusylver in suggesting that when introducing a calorie deficit, with the aim of shedding excess fat, you cannot increase muscle mass. This is largely due to your calorific intake.
In order to increase size and mass, you need to consume a greater amount of calories than your TDEE. However, to ensure that increased calorie consumption doesn’t lead to increased fat storage, HIIT must be performed, as the activity creates a huge energy deficit while also maintaining a raised level of insulin sensitivity.
Taking into consideration that you’re just beginning, concentrate upon running a calorie deficit, while developing muscle that’s metabolically active, to provide a leaner, more athletic appearance.
Once you’ve attained that goal (through researching BMR/TDEE calculators), you can begin to add lean muscle mass. Moreover, your improving level of cardiovascular fitness, attained during your weight loss journey, will place you in greater stead to perform HIIT during your bulking phase.
