Here are the facts: (according to various studies)

• People who participate in tennis 3 hours per week (at moderately vigorous intensity) cut their risk of death in half from any physical/health cause.
  
• Tennis players scored higher in energy, optimism and self-esteem while scoring lower in depression, anger, confusion, anxiety and tension than other athletes and non-athletes.
  
• Since tennis requires alertness and tactical thinking, it may generate new connections between nerves in the brain and thus promote a lifetime of continuing development of the brain.
  
• Competitive tennis burns more calories than aerobics, inline skating, or cycling, according to studies on caloric expenditures.