Related Clues:

• Plod heavily
• Exhausting effort
• Plod through mud
• It's no fun at all
• Go, as through mud
• Trudge through mud
• Walk doggedly
• Walk hard carrying logs?
• Hit - hard work
• Hit hard - work hard
• Work (or walk) involving great effort
• Work long and hard for second record
• Work hard — hard work
• Walk, as through mud
• One may be long and hard