You see how most people train on the treadmill in the gyms?Definitely this is not the way!
This is a pure loss of time, unless of course you suffer from physical limitations.
Look! You have to get out of your comfort zone if you want tangible results.The magic word here is "intensity"
You need to sweat,to gasp for your breath!
Don't set unrealistic expectations!You cannot circumvent hard work!
2. Unsound,not supportive nutrition.
Your nutrition should be synergistic with your training efforts and not undermine them.
If for example you have adopted the mainstream food guide pyramid you are simlpy doomed to failure!You will have to make bold revisions.
Additionally:
-eating clean is an absolute must but isn't enough of its own.
You will have to possess a rough knowledge of the caloric values of the most common foods.
Lots of people severely underestimate their caloric intake!
-too big quantity of a healthy food might eventually harm you!
3. The combination of plenty of aerobic exercise with little or zero resistance training will present you with poor body composition.
You will have to gradually switch to a more favourable proportion.You had better discriminate in favour of resistance training .
When I used to run semi-marathons I started to look like a marathoner.Then I adopted HIIT -mainly hill sprints- combined with circuit weight training and now I look like a sprinter.
Recapitulation
1. Add intensity to your workouts.Only intensity can bring real body transformation!
2. Learn not to undermine your strenuous efforts with an unsound nutrition !
3. Do more resistance training and switch from long,steady cardio to metabolic interval training.