Hello Scottsdalerene,

Working out very hard is bound to make you sluggish and tired. However it should not last all day, unless of course you have just started working out or you dont do it often. Many things could cause your lethargia. Are you eating enough protein in your diet? Do you drink enough water? You dont need to protein binge like body builders but you should have a fair amount in your diet if you work out hard and often. It will help your muscles recover and you may not spend so long feeling tired. Also if you dont get enough water you may feel run down. Water is the most important piece of any diet. If you arent drinking enough water you will severly hurt your exercising ruitines and your general mood.

I hope this was helpful and sorry for the delay...