Most people think you need to be running for an exhaustive amount of time to drop body fat, but in actual fact you could be doing your body more harm than good by doing this. Long distance running places a lot of stress on your body, the impact your joints sustain whilst doing this type of exercise can cause long-term problems, ranging from shin splints to weakened ankles. So yes, running does burn a lot of calories, and you will loose weight if you are running for long lengths of time everytime you workout, however there is a much less time consuming, more effective way to strip fat.
High intensity interval training, commonly referred to as HIIT cardio, is the most effective form of cardio in terms of fat burning, and better still it requires a lot less time! You can do HIIT cardio on practically any machine, bike, rower or treadmill, and you only need to spend 15- 20 minutes of your workout doing it, leaving the rest of your session for weight training.
HIIT is done by exerting yourself in intervals by sprinting for 30 seconds to 1 minute, then lowering the intensity, i.e slowing down your pace, bringing your heart rate right back down again. For example, if the treadmill is your machine of choice, you can sprint at your fastest speed for 30 seconds then walk for 60 seconds, and you only need to do this for 15 minutes to burn up to 700 calories! Research confirms that HIIT enhances the metabolic mechanisms in muscle cells which promotes fat-burning and stunts fat production, another amazing benefit of HIIT is that long after you are finished working out, your caloric burn remains higher as your metabolism requires more calories to repair itself after the intensity you have placed it under.
HIIT cardio is also the best form of cardio to do if you are wanting to keep muscle mass, short bursts of cardio will allow you to preserve muscle and can help build leg mass. For example, if you compare the bodies of sprinters to long distance runners, you will see that sprinters are extremely muscular as opposed to long distance runners who are typically very skinny.
To start with, try introducing HIIT cardio into your workouts twice a week, after your body begins to build up its aerobic and anaerobic endurance you can then add an extra HIIT session per week until you get to 4-5 a week maximum. Take one day off per week, and if on those days you do exercise, try low impact training instead. You will find that after 2 weeks your body fat will start you drop noticeably and you will feel and look more lean without wasting unnecessary amounts of time on cardio. You might find your first HIIT session pretty brutal, but when you know your burned more calories in 15 minutes than most do in 60 minutes you will definitely be back for more!