They feel I need to bulk up, and to improve my upper body strength.
他们觉得我需要变粗壮些，并增强上身的力量。
《柯林斯英汉双解大词典》
2
Various physical changes are possible, including increased body fat; reduced muscle bulk, strength and endurance; and decreased bone density.
体格也可能发生各种变化，如身体变胖、肌肉减少、力量和耐力减弱骨骼密度降低。
3
She pointed to Hareton, the other individual, who had gained nothing but increased bulk and strength by the addition of two years to his age: he seemed as awkward and rough as ever.