Scenario 1: period begins august 1. limit is $1k. spend throughout august and have a balance of $900 on Aug 31. Statement posts that day and you now have a utilization of 90%. You pay the bill on the due date so you don't carry a balance and don't owe interest. You do this month after month and your credit score goes down because your utilization is huge. It looks like you are constantly using 90% of your credit.

Scenario 2: period begins august 1. You pay your current balance down to about $50 every week. On Aug 31, you owe between $50 and $100 and that is what posts to your statement. You still pay the bill on the due date so you don't carry a balance, but your credit score improves over time because you appear to be using your credit, but using it wisely.