Originally posted by: Krassus HIIT is one of the easiest exercises to perform. But before we get to that, you should get yourself a good weightlifting program. Since you're spending 4-5 days at the gym, i recommend a 4-day split, which means you should do something like lift mon/tue, and thu/fri, with hiit on wed/sat and sunday completely off. I highly recommend the 4-day intermediate split in the following thread: i use it myself and its brutal to say the least. Follow all of his advice as far as sets/reps are concerned as well, its very solid.
Linky. But on second thought, since you're cutting on keto, most would agree that 3 days lifting and 3 days hiit will get you better results than 4 days lifting 2 days hiit (remember, you need that one day off on sunday or whenever). So go with the 3-day split, i.e. mon/wed/fri lifting, tur/thu/sat hiit. So for HIIT, start at 4 minutes and add extra 30 seconds on every 3rd time. So your first 2 times you'll do 4 min, your next 2 you'll do 4:30, then the next 2 for 5:00 and so on until you get to 15:00 in a few weeks, then just maintain it there - higher than 15 is too much for your heart. So what you do is go out there, jog for 40 seconds and sprint for 20 seconds, then rinse and repeat. Or do 30/30, up to you. I did suggest 20/40 til you hit 15, and then try 30/30 for as many minutes as you can, it will probably be just over 10. Then get to 15 again and maintain 30/30 for as long as you're cutting. When you're done cutting, forget about any and all types of cardio for the duration of your bulking phase. NEVER do cardio while bulking.