If you are tired of the canned enthusiasm, confusing routines, and sometimes dangerous directives of the latest wave of fat-blasting, kung-fu-fighting, contortionist fitness trends, introduce yourself to Jennifer Kries, the most refreshing instructor to hit home televisions in the past decade. Kries has developed an impressive array of videos and DVDs devoted to what she calls "three-dimensional toning," focusing on "improving the body's efficiency and functionality rather than just changing its appearance."

Perfect Mix is split into three 20-minute segments, each emphasizing a different fitness goal but sharing the same movements and methods. The first segment, "Core Contouring," uses traditional yoga and Pilates moves to focus on improving total body strength. The next section, "Metabolic Booster," is a cardio boost, using light weight training to burn calories while working different muscles groups throughout the entire body. Finally the yoga-based "Rejuvenation" segment brings down the heart rate and promotes flexibility and mindfulness.

Kries is a patient and surprisingly empathetic instructor--she is hyperaware of her own freakish flexibility, and constantly reminds viewers to "listen to your body and never move to the point of pain." Because she is so focused on breathing and precision of movement, the best thing about the DVD is the ability to use slow-motion controls to really improve your form (this is a no-frills DVD, with a music-only option, which is peculiar; the point is not to stare at a TV screen, and the teacher's vocal guidance is usually an essential part of that process). Kries moves through the routines rather quickly, only doing a few repetitions of each exercise, and while this prevents boredom it also makes it easy to skimp on the moves and not give the full attention needed to really feel the workout. When done correctly this is the perfect class to follow a long hard day at work--it is both energizing and invigorating without being physically and mentally exhausting. --Daphne Durham