The law of attraction may not be the key when it comes to the psychology of choosing the best workout buddy. Personality and temperament go a long way in finding a compatible exercise partner, but the traits can be very different from those you cherish in your romantic partner or best friend.
Rather than following your heart, use a common sense strategy. What works for you is as unique as your own personality, your personal likes and dislikes, your goals in an exercise program and your individual resources - such as your available time, money and space. To find a good match in a workout partner, look for someone who has similar orientation as you. What are your personal preferences? Do you prefer to work out in the morning or evening? Indoors or outdoors? At home or in a gym?
For some of the personality characteristics you might want to consider in picking a workout buddy, read my comments in Linda Wasmer Andrews blog "Minding the Body: The guide to health and happiness".