General physical preparedness (GPP) is valuable to a weightlifter. Why? GPP generally relates to your fitness level. I can hear you already… “dude, I'm a weightlifter. I don't need to run”. You're right, you don't need to run but you do need to be able to get oxygen to your muscles efficiently. This unfortunately means that you'll have to get your heart rate up regularly, work on flexibility as well as working on those strength gains.
If you want your body to adapt to the changes you try to force on them (weight training) then you will have to ensure that your body can utilise oxygen, other body chemicals and hormones efficiently.
Throwing in one or two days of general physical exercise (cardio, plyometrics, calisthenics, etc.) per week will improve how your body processes oxygen. Working on mobility and flexibility constantly along with your regular training (vital to GPP) will also increase your ability to handle the bar efficiently.
This will be an asset not only to your meets (when you're heart's racing) but also when your coach programs nasty EMOM’s and complexes as well.
Remember to lift smart, train hard and you'll set PR’s