some points from the article, Fast Fat Loss Workouts
Remember, getting lean is at least 85% nutrition, so don’t even think about starting a fat loss focused phase with a crappy diet. It just won’t happen.
The first thing I always tell people before they embark on a fat loss phase is to keep the heavy strength work in the program. Even if you train strictly with bodyweight that means you still need to keep high resistance, low rep (5-8) work in the program. If you immediately abandon strength work in favor of high reps you will lose muscle and strength. The end result is a small, soft physique. You definitely don’t want that.
The first thing to add in is high intensity, low duration conditioning like hill or sled sprints. If fat loss is your main focus right now you will only need two or three days of heavy training to maintain your muscle mass and strength. The other days should dedicated to more fat loss style training.
Let’s say you strength train on Monday, Wednesday and Friday. If you are currently doing zero conditioning start slow and add in two 15-20 minute sessions on Tuesday and Saturday. My first choice is hill sprints or sprints with a sled. Sand sprints on the beach are awesome as well. And you can never go wrong with the Prowler or a jump rope.
The intensity should be high and your heart rate should be higher. You don’t have to puke but it shouldn’t be comfortable by any means. So get comfortable being uncomfortable.
If you’re new to sprinting take it slow. A half dozen 20-30 yard sprints is a good start. Then, a few weeks later you can work up to ten 50’s. Six weeks later you could push it to somewhere around 1000 yards total for a good fat loss workout. In other words, ten one hundred yard sprints. Run the length of a football field up hill, on the beach or on flat ground with a sled then walk back and repeat.
Four hundred meter sprints are hard to beat for fat loss but that takes a long time to work up to and is definitely quite a bit riskier from an injury perspective. If you have a really long hill or a huge stretch of grass to run with a sled on you could work past 100 yards after about eight weeks of sprinting. If that’s not an option be very careful when working your way up to the 400 and make sure your sprint technique is spot on.
Two days of sprinting per week will be enough for most people. If you’re in shape and athletic there’s no reason you couldn’t get up to three or four, as long as least one of them is of lower intensity.