Need more info.
You are 5'9" 160 lb. 160/69 = 2.31 lb/inch, a solid build.
What is your frame size? Measure neck below Adam's apple, chest at nipples & below shoulder blades, wrists at wrist joint, ankles just above ankle bone, feet size. And waist, level at the belly button. There are on-line health charts, and calculators to understand your frame size and body density.
If you are a small frame (rib cage & major bones), about the lightest you could be and still have sound whole body strength would be 138 lb, or 2 lb/inch. 131 lb is 1.9 lb/inch, weight I wouldn't advise pursuing beause it could lead to an eating disorder. Top world class 5,000 meter runners are in this range, but can be heavier.
When pursuing a leaner body composition, it is VITAL that natural, unprocessed, unsugared whole foods be your daily diet. Every cell needs to be optimized, and diet is part 1. Part 2 is training. Part 3 is rest. Neglect any of these at your own peril. Injury will be the result.
One tip: Train on soft surfaces to maximize the plyability and spring in tendons and ligaments. Alternate hilly steady runs and flat runs. On all runs focus on relaxed in-sync movement with deep, light footstrokes.
Another tip: Train consistently, i.e. daily (6 days/week). Not hard every day.
Another tip: Patiently build a big aerobic engine. Look up triathlete Mark Allen's training.
Weight alone will not bring optimum performance.
Last tip: Kindness to others is the best path for optimizing you.