A Fitness training certification from IAHEWORLD  means that you’ll have the practical and scientific knowledge to work in a variety of fitness facilities, including health clubs, gyms, university, corporate, and community or public fitness centers, and positions ranging from freelance personal training to full-time and beyond. A Fitness training certification from IAHEWORLD means that you’ll have the practical and scientific knowledge to work in a variety of fitness facilities, including health clubs, gyms, university, corporate, and community or public fitness centers, and positions ranging from freelance personal training to full-time and beyond.