A lot of athletes spend too much time working in rep zones not in accordance with their goals. An old school 12/10/8/6/4/2 without knowledge of what you want to accomplish is a waste. Say you are in a strength phase of your lifting. Let’s say you use the 12 and fail at it. Fail with the last rep of 10. Fail with the last rep of 8. Fail with the last rep of 6. You get to your set of 4 and it feels like it weighs 50 more pounds than usual. Do you think your strength will improve using this system? Absolutely not. Try flipping it around and working from the bottom up 2/4/6/8/10/12. AFTER A SMART WARM UP. Also the heavy sets will have a carry over to the higher rep sets making them feel “lighter” You also trained the zone you were interested in and not the wrong fiber types.
Let’s say you want to get stronger in the Squat and you want to get 300×5. A smart warm up looks like 45×12, 135X8, 185×5, 225X3 275X1-2, 300×5. Don’t waste your gas on 5 rep sets with 225 and 275. 275 is a “neural primer” that makes the bar not feel like a truck on your shoulders when 300 arrives. That is the only purpose. Doubt inhibits contraction and you eliminate the “holy shit this is heavy” when you un rack the 300.
Your body will adapt specifically to the demands you place on it. Train smart.