Jillianmichaels.com does not explicitly state age restrictions for using its resources, such as fitness programs, workout videos, or recipes. However, it is important to consider that many fitness programs may involve physical activity that can vary in intensity. Therefore, individuals under the age of eighteen may benefit from parental guidance or supervision when using these programs to ensure that they are engaging in activities suitable for their age and fitness level. Additionally, those with pre-existing health conditions or concerns should consult a healthcare professional before starting any new fitness regimen. It is always wise to check the specific terms and conditions on the Jillianmichaels.com website for the most accurate information regarding usage guidelines.