Just a little more fatigue in your workout!

Get in a little more. Work with high reps: arms series, leg raises, abs, etc, whatever it may be, do your regular amount then hold the contraction for up to 30 sec until the muscles fatigue. You'll find a new burn and a new level of fatigue with this type of isometric strength work. Note* excellent for rehab BUT remember to breathe, do not hold your breath while holding a contraction.