DB THRUSTERS - If you notice any coning in the overhead position or if you have a tendency to collapse in the bottom of the squat try to focus on managing proper posture, breathing mechanics, core pressurization, and/or joint stability, sub: Less weight, Box/Target/Supported Squat + Press, or Air Squats
Double/Single Unders - To avoid the added pressure to the pelvic floor that DUs/SUs can create, sub: Taps, Row, Bike, Quick Step Ups, Calf Raises. If you're postpartum and working towards rehab-ing your core and pelvic floor you can choose from the same subs for pregnancy and/or scaling the number of DUs/SUs down to a number that is realistic for your to practice proper positioning and pressure. Any leaking or heaviness in the pelvic floor is a sign that you need to adapt your approach or change the movement to less impact.
BURPEES - Pay attention to any coning or doming you have in the plank position of the burpee or any sensation of pressure on your pelvic floor as you hop back or hop forward. Feel free to sub: No push up burpee, Elevated burpee, Step back/forward burpee, Air Squat + Elevated Push Up, Table Top (all fours position) + Air Squat, Ball Slams, KB Swings, Farmer/Goblet march, Glute Bridges, Sumo Deadlift High Pull
BOX JUMP/JUMP/SKIP OVERS - This is going to be all about managing the impact and pressure to your core and pelvic floor. The SHIFT options for smaller Jump/Skip Overs are good for helping you achieve the stimulus with a little less impact. You can ALWAYS substitute Step Ups if you want zero impact or even KB Swings if you want to get a little more explosive with your hips. For pregnant mamas, please remember that if you are unsure if you can complete the movement because of balance, strength, or coordination it may not be worth the risk of potentially falling or busting up your shins! For mamas further along in their Postpartum you can try a lower height of box to practice that two foot take off and landing without the extra impact. Focus on your breath and posture throughout the movement and do less reps if that helps you concentrate on good technique and awareness in your body.