Full of energy and vigor; very lively and energetic (often used affectionately, especially for children).
子どもたちは公園で元気いっぱいに遊んでいる。
The children are playing energetically in the park.
朝ごはんをしっかり食べて、今日は元気いっぱいだ。
After a good breakfast, I'm full of energy today.
あの選手はいつも元気いっぱいで声援にも応える。
That athlete is always full of energy and responds to the cheers.
祖父は年の割に元気いっぱいで畑仕事を続けている。
My grandfather, considering his age, is full of vitality and keeps working in the fields.