I’m keeping this one short and to the point:
A combination of both aerobic and resistance exercise training will provide you greater benefits for weight loss, fat loss, and CV fitness when compared to doing just one or the other.
Evidence is provided via this 2012 publication:
Ho SS1, et al. BMC Public Health. 2012 Aug 28;12:704.
The effect of 12 weeks of aerobic, resistance or combination exercise training on cardiovascular risk factors in the overweight and obese in a randomized trial.
CONCLUSION: A 12-week training program comprising of resistance or combination exercise, at moderate-intensity for 30 min, five days/week resulted in improvements in the cardiovascular risk profile in overweight and obese participants compared to no exercise. From our observations, combination exercise gave greater benefits for weight loss, fat loss and cardio-respiratory fitness than aerobic and resistance training modalities. Therefore, combination exercise training should be recommended for overweight and obese adults in National Physical Activity Guidelines.
And this 2014 publication:
Effects of aerobic training, resistance training, or both on percentage body fat and cardiometabolic risk markers in obese adolescents: the healthy eating aerobic and resistance training in youth randomized clinical trial.
CONCLUSIONS: Aerobic, resistance, and combined training reduced total body fat and waist circumference in obese adolescents. In more adherent participants, combined training may cause greater decreases than aerobic or resistance training alone.