Were you an active person before pregnancy?
You had a baby 1 month ago, you are breastfeeding, you probably should not be sleeping straight.
So... Start slowly, you can do the 45 minutes of low-intensity cardio... take the baby for a walk for example... about 2-3x a week... overtime you can increase the intensity or frequency or both. The idea is to continue exercising and not to fatigue yourself to the point you can't recover.
Consistency is the secret. It is to do the same right thing every single day. Also... do not forget the diet, to lose the extra weight, you will need a proper diet. Which does not mean stop eating or make absurd restrictions. You are breastfeeding for God's sake.
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