Strength training is extremely essential for building muscle. Some even say it is a prerequisite, with the addition of getting the right amount of proteins in the diet. The cardio routine one follows helps to aid the weight loss process and thus making more space in the body to build muscle.
But a cardio activity by itself has never been associated with gaining muscle. But many fitness professionals disagree, According to Corey Phelps, an NASM-certified personal trainer, running intervals, in which you rotate between 30-second sprints and 30-second recovery periods for 10 to 20 minutes can not only effectively burn fat but also help build muscle. He also says one can add incline sprints on the treadmill or outside on the stairs. "The incline will target the quads, glutes, and hamstrings, and the sprints will activate core muscles.” He adds, "Run up the steps as fast as you can. Propelling the body upward is tremendous work and creates a perfect environment for muscle growth."
If running isn't your speed, Corey also suggests rowing intervals, alternating between sprints and recovery reps to build muscle. "Rowing targets every muscle in the body, especially the glutes, hamstrings, and quads," she said. "The explosive power used to press off the footrests targets the lower-body muscles."
Of course, Corey noted that you can't blast away bad eating habits with cardio and strength workouts. When it comes to building muscle, a balanced diet focused on adequate protein intake is key. Finally, don't be alarmed if you see the number on the scale increase slightly; muscle weighs more than fat, so this is normal. Instead, focus on how your clothes fit and watch for increased muscle definition. If you stay consistent, you'll slowly but surely start to see results.