strenuously (adv.)

• actively
• animatedly
• ardently
• arduously
• assiduously
• briskly
• diligently
• energetically
• fervently
• forcefully
• forcibly
• hard
• hardly
• heartily
• indefatigably
• industriously
• intensely
• keenly
• laboriously
• lustily
• manfully
• painfully
• relentlessly
• sedulously
• spiritedly
• tirelessly
• unsparingly
• vehemently
• vigorously
• vivaciously
• zealously
• zestfully