That would be considered kneeling at the waist and stretching
I would say hat now is the perfect time because peak bone mass happens at our age. Bone strengthening exercises are always good for your body no matter what, so encourage her/him to do it. I'm guessing the age is about 11-18 maybe...
Hope this helps... mark as Brainliest plz
Answer:
negative energy balance
Explanation:
Negative energy balance occurs when caloric intake is lower than energy expenditure