Does weight training make you sluggish?

One of my members keeps asking me why she doesn't have stamina for aerobics classes since she started weight lifting. I notice she will leave two or three times during class (not just my class, but another instructor's also). She says she just poops out before the end of class, and she blames it on weight training.

Sounds to me like there's some medical problem here. Is there any way weight training reduce your stamina for cardio work? (She does not have a lot of definition, so I don't know how much weight training she's doing.)

Please advise,

I wonder if she's doing weight training the same day as her class

Of course, if you lift with enough intensity. Consider that she is coming into the cardio session with reduced energy and depleted glycogen reserves. Most likely she needs to be more gradual about increasing her total training volume.

Sling Skate

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