solo,I wanted to see what it would do by itself. I ran it 2 a day to start, then after 2 weeks I bumped it up to 3. Seriously, the 2 and 3 day pumps were bad ass! The last day I used a sample pack of c4 I had, WOW! It was arm only day, it felt like the skin was gonna rip! I respond well to things of this nature, but it was an awesome run!