Updated December 11, 2012.

Unlike the elaborate big gyms and health centers with every piece of equipment imaginable, you may want to fit out a personal training studio or even a well-equipped home gym. You have to be selective. Here are the top ten pieces of equipment for a small-scale gym.

1. Training Bench(s)

A training bench is an adjustable platform used for performing weight training exercises. You should be able to adjust the backrest from the flat position to incline, and possibly the footrest.

Many fancy types are available, but look for a well-constructed and easily adjusted bench with the basics. A personal training studio may need at least two of these.

2. Dumbbell Set

A set of dumbbells is mandatory, ranging from very light to very heavy, depending on the user group profile. Dumbbells come in variety these days, from plastic coated in a variety of colors to adjustable weight sets. Get a set with rack and save loads of time and inconvenience.

3. Barbell Set

You can go several ways with barbells. Go for the Olympic bar, squat rack, bench press rack and removable plates if you can afford them. Otherwise, a set of fixed or easily adjusted barbells with smaller bar will serve you well. Again, a rack for storage is essential.

4. Kettlebell Set

Kettlebells provide an alternative to dumbbells because they activate a slightly different muscle profile, and although not necessarily superior, they are popular and worth working with. Kettlebells come in a variety of weights, sizes -- and even shapes.

5. Pullup Frame and Bar

This is for doing chinups and pullups. Look for a squat rack with a pullup bar incorporated to save cost and space.

6. Treadmill

A treadmill for running, and walking, adjustable for incline and providing heart rate monitoring and other standard settings is a necessity. Get a robust, commercial gym standard treadmill if you can afford it.

7. Stationary Bicycle

The stationary bike is an alternative cardiorespiratory trainer to the treadmill and rowing machine. Get all three because they emphasize slightly different neuromuscular approaches to aerobic fitness.

8. Rowing Machine

Using upper body and lower body large muscle groups, this is a fine aerobic and anaerobic trainer that is often overlooked.

9. Fitness Ball (Exercise Ball)

A remarkable number of exercises can be designed around a fitness ball, especially core and abdominal exercises. They may not be used by your heavy iron pumper, but they offer variety to a range of clients at different levels of conditioning and expertise. You may need two.

10. Accessories.

Add smaller equipment items like a rollout wheel for abs, wooden bar for upper body stretching, and bands and tubes for rehabilitation and 'soft' resistance exercises.

Summing Up

You may have noticed that there is no machine equipment in this lineup. Equipment pieces like cable machines, lever machines, Smith machines and others of great variety, standard and function are standard equipment in most large gyms, except perhaps for many of the dedicated Olympic and Powerlifting gyms.

Machine equipment provides a particular service and it's somewhat elitist to discriminate against such equipment in favor of free weights. Even so, for small gyms, this type of equipment can be expensive to buy or rent. You or your clients can usually get by without it.

One thing to consider before investing in equipment, of any type, is the space required to safely operate such equipment, especially when more than one person is exercising. Keeping your public liability and professional indemnity insurance up to date may be important as well.