The average exerciser looking to improve body composition can lose fat while improving lean body tissue over time and beginners will likely get the greatest benefits of both fat loss and muscle gain. Women who followed a cardio and strength program for 6 months, lost an average of 10 percent body fat while increasing their muscle by about 2.2 percent, while men experience similar improvements after following a 16-week strength training program. This shows that beginners respond quickly and efficiently to strength training and cardio. The key is to keep a balance of both cardio and strength training, whether you're a beginner or a more experienced exerciser. Doing all cardio with no strength training can compromise your muscle mass while doing only strength training without cardio can compromise your fat loss.
For the average exerciser, having a balance between the two is the best way to maximize fat loss while preserving muscle mass.