This seems to be a parallel with Isaiah 40:30.
(Isaiah 40:30 NAS77) Though youths grow weary and tired, And vigorous young men stumble badly,I was reading over this just a few days ago. The promises of God keep coming back to refresh us. What was the basis of this promise in Isaiah? You need to read the next verse.
(Isaiah 40:31 NAS77) Yet those who wait for the LORD Will gain new strength; They will mount up with wings like eagles, They will run and not get tired, They will walk and not become weary.
To receive the promise we need to wait on the Lord. This ties in with Proverbs. If you read the surrounding verses you see that the promise is embedded in the study and application of Wisdom.
So? Promises have conditions. The sustaining hand of God is tied to us spending time with Him and drinking from the wisdom He has do offer. Schedule Him in.