Some ways that the message or speech could be contradicted by the delivery or body communication can be the result of not having energy to a speech that should or having too much energy when talking about something serious. This can cause the audience to not take your speech seriously and not trust what you are delivering.
I agree, a speech will fail to be heard if you are very low energy. And if you have too much energy in a serious situation, this can be troublesome.
Well said Grayson. I know this to be true. I often do not have enough energy when I am speaking.