Running is a great form of exercise. It's hard, don't get me wrong, but like any form of exercise your body gets used to that form of training. When your body becomes adapted to your training, you burn less calories than you think! Many people are relying on a machine to tell them the amount of calories they burned or a fancy fitness tracker like a garmin or fitbit. Truth is, they are usually way off and overestimating your caloric burn.
You have to remember those "tools" are generalized and not specific to you, your body composition, your age, your metabolism, fitness level, genetics or even the environment which all play a huge role in your caloric burn through exercise. Since it's hard to tell how many calories you are burning through training, you should consider looking at your metabolic equivalent which is how many milliliters of oxygen a person consumes per kilogram of bodyweight while doing a specific activity. One MET is about equal to the amount of energy it takes to sit still. The more intense the exercise the higher the MET and more calories are burned during that activity.
There are some great exercises that you can perform that have a HIGHER MET than running. Variety is the spice of life and I think your body might need the change from the boring cardio from running that it quite possibly might be adapted to!
#1 – Kettlebell Swings- MET of 8
Kettlebell swings are great for your core and overall body development. Be sure to use a weight that is challenging but with good form.
#2 – Burpees- MET of 8
Burpees, you can love them or hate them but they are great for the cardiovascular system!
#3 – Jumping Rope- MET 12
While it does require some skill and coordination, your heart rate will be jacked up through the roof.
#4 – Uphill walking with a loaded carry- MET of 9
Depending on the weight you are carrying and the steep of the incline you can be burning a lot of calories from just walking. Don't underestimate what seems "easy"
#5 – Rowing- MET of 4-12
Rowing is a great low impact way to increase your heart rate or keep it easy for recovery. As you can see you can keep it at an easy pace or ramp it up and kick that calorie burn into overload.
In the end, you want to continually be challenging your body to new things. Keeping the same routine every day will lead to burn out and then your body will stop adapting to your training. All of which will cause you to plateau in your results.