We all have crazy schedules and busy lives. But, when it comes to your workout, make sure you have time to warm up and cool down. Even if you arrive late, give yourself a minute to get your body warm; and even if you have to leave early, give yourself a minute to cool down and stretch.
Warming up the body properly helps you to find a proper breathing rhythm, get the muscles warm, jump start the cardiovascular system and get the body moving. Your barre workout is a lot more successful, sooner, when your body is warmed up. If you come into a barre workout (or any workout really) without a proper warm up, you will find that it takes a few minutes to get your body up to speed on your desired level of intensity. Whereas when your body is warmed up, when it comes down to it, you can dive right in to any level of intensity that works for you. This sets you up for success throughout your entire workout and will also help reduce your risk for injury.
Likewise for a cool down. After the intensity of the workout is over, your body needs time to cool off, set its breathing back to neutral, lower the heart rate and the muscles need to be stretched to prevent tightness, reduce soreness, and increase elasticity and strength. If you finish your workout and head out of the studio and/or gym right away, your muscles are more prone to tightness and soreness, which increases your risk for injury in the workouts to follow. Not only that, but allowing your heart rate to come down and giving your body a minute to cool off and return to a neutral state is important.