There is a common misconception with adults that just because they are older, they somehow automatically gain strength and combat ability as they age. These individuals would think they could beat up any teen if they wished, even though the last time they participated in any physical activity was perhaps tossing the old pigskin at a family party during Christmas time.
A teen with a developed body has peak testosterone levels and growth hormone that will never be higher in the rest of his life, especially one that plays sports. While in general teens are not as strong as adults, there are many athletic teens that cannot be underestimated. If you are an out of shape adult, don’t think you can overpower an athletic teen unless there’s a huge size difference.