If I asked you what type of exercise people should do, it’s likely you’d answer with something like this: “Oh, some kind of cardio, like walking or running or biking. And some weights or weight machines. Maybe some stretching.”But do you ever wonder if you can get away with less? What do you really have to include in your workout in order to stay fit? Is running enough? Or if you dread cardio, can weights suffice? What about stretching? That seems like something you could leave out without too much damage.Well, you can leave out anything you want, but if fitness is your goal, you have to include the big three broad categories of exercise in your workouts: cardiorespiratory exercise (also called aerobic or stamina-building activity), resistance exercise (think strength training or weight lifting), and, yes, even stretching. You cannot leave one of them out if you want to achieve “fitness.”You may ask, “Do you seriously mean to imply that a marathon runner who does no resistance work isn’t fit?” It’s very possible, because fitness encompasses a high level of function within multiple body systems. Being “fit” entails performing numerous types of physical activity well.MORE: Beauty Tips for ExercisersFitness requires five health-related components:Cardiorespiratory endurance: How well or efficiently your body uses oxygen to make energy. A high level of cardiorespiratory or aerobic fitness allows you to sustain high-intensity activity for long periods of time and is correlated with health and longevity. That marathoner would have this box checked.Muscular endurance: The ability of a muscle to contract repeatedly against a submaximal resistance or to hold a contraction for an extended period. You use muscular endurance for many routine tasks such as cleaning, shopping, carrying children, yard work, etc. The marathoner would have a large degree of muscular endurance in her lower body muscles, but not necessarily in her upper body.Muscular strength: How much resistance a muscle can overcome one time. In other words, the most weight a muscle can lift or move. Here, the marathoner would be lacking, because to have decent muscular strength, you have to move your muscles against significant resistance—more resistance than running provides.Flexibility: The degree to which you can move a joint. The length of your muscles as well as the connective tissues (tendons and ligaments), and the bone structure determine this. People vary widely in their natural flexibility and their need for stretching. For general fitness, all you want is a normal range of motion in your joints. Not so little that it inhibits function, but not so much that it makes you unstable and injury prone.Body composition: The percentage of your body that is fat as compared to lean mass (mainly bone and muscle). The changes you need to make in this component largely affect the type of workouts you should do, mainly in terms of intensity and time. I’ll cover that in future articles.Your workout, if you aspire to being fit, must address all five components of fitness. That means you have to do some cardio (at least 60 minutes a week), you have to lift weights or do some other form of resistance exercise a couple of times a week, and you have to do some joint range of motion activity, whether static stretching or active range activity after each workout.Now what about balance training and speed training and all of those fancy things you hear about? What about those heavy balls and big balls and balls with handles and cones and wobbly platforms to stand on?These are part of a broader definition of fitness. These are related to performance aspects of fitness rather than health aspects. You might think of it as athletic fitness. Components of performance or athleticism include balance, agility, coordination, speed and power. And while these don’t play a major role in your ability to perform the necessary health-related physical activities, they sure play a role in how good you look while you’re doing them. It’s a simple matter of awkward versus graceful, of efficiency versus inefficiency.And having a degree of athleticism also opens doors to the types of physical activities you can comfortably participate in such as dance, rock climbing, or, your dream come true…curling.MORE: Fit Fitness Into Your DayThis website is dedicated to helping you achieve beauty, so I am going to encourage incorporating these performance aspects of fitness into your workouts as well. If you are not doing the big three health-related activities yet (cardio, resistance work and stretching), start there. They are the most important. But if you are already doing those, begin to add in some balance training, some power drills and some exercises for coordination.Following is a basic list of physical activities to incorporate into your workout. If you are starting from scratch, proceed with the order given. If you’re already exercising, look down the list and address the first item you’re missing. These are listed in an order that takes into account the relative contribution to fitness and degree of skill needed.1) Cardiorespiratory exercise: If just starting, begin with walking.2) Resistance training: Start with light weights or resistance bands.3) Stretching: Five minutes of gentle joint movement after activity.4) Balance training: If in doubt, start with standing on one leg.5) Coordination: Focus on a challenging movement pattern until you master it.6) Power: Involves some air moments—simple jumps, weighted ball tosses.7) Agility: Do some direction changes while moving, like side to side shuffles.8) Speed: Start by incorporating some faster intervals into your cardio workout.Not everyone can or should do all eight activities. It depends on your health status and your body structure. I will cover each area in detail in future articles, guiding you according to your fitness level, interests, capabilities, opportunities and schedule. For now, address some area that you’re missing. All of them will add to your health and beauty.MORE: Boost Your Brain With Exercise