You never heard the words Load Management in Jordan, Bird, Magic era....they played unless that were really hurt.....Barkley is rite if you're not injured get up and play the game....
Things changed. We know more about sports medicine and also these guys are covering way more ground now. Lighter dudes were just standing around near the key and the miles today on heavier bodies add up. Giant bodies are running 2.5 miles per game on hardwood in basketball shoes.
Soccer players have better conditioning, play on soft grass, aren't giant human beings, have seasons that are half as long, and they still load manage because start/stop running around is so hard on the body.