Lack of exercise can be detrimental _______ physical fitness.

Detrimental to: 
English Meaning - Causing harm or damage. 
Bangla Meaning - ক্ষতিকর। 

• Detrimental এর পর appropriate preposition হিসেবে 'to' ব্যবহৃত হয়। 

Example Sentences: 
- Smoking is detrimental to your health.
- Procrastination can be detrimental to meeting deadlines and achieving goals.  

Complete Sentence: Lack of exercise can be detrimental to physical fitness.

Source: A Passage to the English Language by S.M. Zakir Hussain.