Performing a particular amount of rounds of the circuit or an AMRAP (as many rounds as you can) within a supplied period of time are wonderful ways to get a killer conditioning exercise in. The basic spinal erector exercises are deadlifts and entrance squats. You can do dumbbell Romanian deadlifts, https://messiahnpnki.fitnell.com/74089205/the-single-best-strategy-to-use-for-dumbbell-set-and-rack