Hi:
muscle definition has a hard time showing through, no matter how assiduously you lift, if there is fat covering the muscle.
It's not that you need to do more cardio, you are already doing probably too much cardio (way more than I do), but you could probably stand to examine the quality of the cardio time you engage in. Don't train more, train smarter. Make sure you are not always doing the same activity because the body adapts quickly and gets very efficient, meaning you no longer burn the same number of calories doing the same routine after several months. You need to shake things up by keeping the body guessing with different cardio types: some step, some kickbox, some running, some swimming, some walking, some boxing, some spinning, some bootcamp, some circuit training, etc. It is also good to make sure that at least one of your cardio sessions per week is spent on interval training/HiiT which ramps up fitness levels, fires up the metabolism and really works that heart at your anaerobic threshold. 20-30 mins of HiiT is all you need at a time, thus freeing you up to get in a good half hour's weight training in after that, and then call it a day and get some rest. I wonder if you are doing too much and never letting your body rest to rebuild those muscle fibres? I personally think 3-4 cardio sessions per week is enough to secure heart health, since weight training also benefits the heart.
Take a look at your weight training also. Are you doing 3 or 4 total body routines or is all your time spend on 2 or 3 day split routines? If you are used to total body routines, then probably you could be lifting heavier than you are. For a change, try a 2-3 day split using heavier weights and a rep range between 8-12 or 6-8 depending upon the exercise, muscle group and weight selected (see PUB and PLB, going up pyramid or down pyramid only). You could work lower body one day, upper the next. Take a day off lifting and then repeat this sequence. An alternative is to do lower body one day, then split the upper body into two other separate days (see GS series and PS series). You might also choose to do just one muscle group per day and really work it (see 4DS, S&H). Working less muscle groups per day gives you more time to work the muscle group you focus on and the chance to go heavier because the muscles are not so pre-fatigued by working a previous muscle group. For example, I cannot do a great job with my shoulders if I have already worked chest because the deltoids are recruited in the chest routine. So, I work these two groups on different days and get more benefit from each weight session.
Many people find that incorporating weights into their cardio training helps them lose fat all the faster, so you might try a month where you sub two of your cardio days for circuits (C&W, LIC, Bootcamp, High Step Training). I have always found that I never leaner than after my 2 week back packing holidays in the Rockies where day long hikes (cardio of the steady state type) blend perfectly with weight training for the lower body (hauling a 40 pound backpack). This is, for me, the ultimate way to get lean.
The third part of the equation, and many say, the most important part, is nutrition and diet. You need to be honest and ask yourself if you are either eating way too many calories per day or too few, each can result in no fat loss, despite your best efforts. Your diet needs to be fibre rich, nutrient dense, heavy on the fruits and vegetables. Make your plate is as colourful as you can get it. Eliminate most snacking. We overestimate how much food we really need. Don't fall into the trap of thinking, "well, I just burned 500 cals doing KPC so I deserve this peanut butter sandwich/slice of cake/packet of M&Ms," whatever your poison of choice. Most of the time we mistake thirst for hunger and eat more when we are better off drinking. So after that next hard workout, drink plenty of recovery fluids first, then eat later when you can trust your body's signals. Head for quality proteins, an apple and a yoghurt, or a bowl of healthy cereal and milk.
The fourth part of the equation is making sure you are getting enough and good quality rest and sleep (these two are not the same thing). When we do not get enough sleep, our cortisone levels in the body increase and this causes us to eat more, and usually of the wrong sort of carbohydrate foods. I have proven this rationale to myself. Two years ago, I went back home to the UK for two weeks, leaving my family here and boy, did I catch up on some truly needed, undisturbed sleep. During those 2 weeks I lost about 5 pounds just because my body was so well rested and knew when it was really hungry and when it wasn't.
The thing to remember is that this is no one, perfect magical formula that works for everyone. Some people NEED to do cardio every day, others find twice per week is enough. Some people feel better and lose body fat faster on endurance type lifting only, others swear by heavy weights exclusively. Cathe has many rotations in her rotation library. You could pick one and follow it and see if that emphasis helps you shift some fat and see more definition? If not, try another, with a different emphasis to find what works for you.
Bear in mind also that genetics plays a large part in determining how you will look after spending all this time on exercise. If you are genetically pre-disposed to be a pear shaped woman, for example, you will never look like mesomorphic Cathe who builds muscle and definition very easily. If you are an ectomorphic bean pole, all the cardio in the world will never help you achieve much definition, you are going to have to limit cardio and use heavy weights to achieve muscle growth. Age is also a factor and here we are fighting biology. Biology wants us to increase waistline, hip, thigh, butt girth as we age and lay down some fat stores since our estrogen levels are dropping and estrogen is stored in fat cells. If this is happening and you cannot shift it even with a superb diet and smart exercising, then acceptance is the way to go, for sanity's sake!
Hope some of this helps,
Clare