Nearly none, in slang

• The least amount
• Worthless amount
• Nothing much, to weightlifters?
• Least amount
• Exercise that's not worth much?
• A = B = AB (anything at all)
• FA team in pub, possibly swapping tips!
• Absolutely nothing
• Very little, in slang

Wiktionary Word definitions in Wiktionary
n. (alternative form of diddly-squat English)