This Instructable will show you how to make an inexpensive Bulgarian Traning Bag. It requires no specific skills to make this bag and takes 30-60 minutes. This bag can be made to weigh however much you'd like within a reasonable range, and used for a variety of different weightlifting exercises, including squats, lunges, curls, and other free-motion swinging exercises.

Step 1: Gather Materials

For this project, you will need:

Cutting tool (box cutter, scissors, anything that can cut rubber and zip ties easily)
Heavy Duty zip ties - $5 at a hardware store
Tractor tire inner tube - free
Weight filler (rubber mulch is used in the example) - $10-15
Duct tape - $3
Rubber hose (3/4" diameter heater hose) - $1-2/foot

Total cost: $20-30

Tips:
A tractor tire inner tube can probably be found for free if you ask the right people. Companies that deal with tractors will often have old ones they are happy to get rid of.

Decide on the weight filler based on how much you want the bag to weigh and how big your tractor tire inner tube is. You can make a heavier bag with a larger inner tube and a heavier filler (e.g. sand) or a lighter bag with a smaller inner tube and a lighter filler (e.g. packing peanuts).

If you buy the rubber hose in the springtime, you can often find heater hose on sale!

CAUTION: Be careful when cutting with tools such as a box cutter. Always cut away from yourself and cut in a controlled manner.

Step 2: Make First Cut

Once you have gathered all of your materials, the first thing you need to do is make a cut in the inner tube. This cut can be made anywhere, as long is it is perpendicular to the curve of the inner tube (the size of the bag will be determined by the second cut).

Step 3: Roll 1st Cut

After making the 1st cut, the next step is to roll the 1st cut. This is done by starting at the outer diameter of the inner tube and rolling towards the rest of the inner tube. Continue to roll until you have enough roll sticking in past the inside diameter of the inner tube for the size handle you would like there. When you are sure you have the desired length handle, do the following so that you know where to make the second cut:

-Make a mark on the inner tube for how far in you rolled the cut side
-Unroll the cut side
-Measure and record the length of inner tube you used for the roll (from the cut to your marking)
-Re-roll the 1st cut, and tie it off with a zip tie (see photo)

Step 4: Make 2nd Cut

You are now ready to make the 2nd cut and the Bulgarian training bag will soon begin to take shape. You will need the distance needed for a roll found in the previous step.

-Measure and record your shoulder width, or however long you would like the bag to be
-Add this distance to the length of inner tube needed for a roll found in the previous step
-Make a mark on the inner tube that is this calculated distance from the first roll already made
-Cut the inner tube at this marking in the same way as the first cut

Step 5: Fill Bag and Make the 2nd Roll

It is now time to fill the bag! Make sure the zip tied end is secure, and then begin pouring the rubber mulch into the open end. Fill the rubber mulch up to where it fills the bag, but you can still roll the end enough for the correct size handle. This may take a little bit of trial and error of rolling the handle and seeing if you need to add more mulch or dump some out.

Also at this time, you could do some trial and error with different fillers to try to get a bag with a weight you desire.

When you are sure you have the correct amount of filler, roll the open end for the final time and zip tie it shut as you did with the other end. You now have a usable training bag, but don't use it quite yet, there are still a few features to add!

Step 6: Add Secondary Handles: Part 1

Steps 6 through 9 will all have to do with making secondary handles across the outer diameter of the bag.

The first thing you need to do for the handles is decide how long you want them to be, probably a little wider than your hand width when gripping a handle. Cut the heater hose the desired length for each of the two handles.

Step 7: Add Secondary Handles: Part 2

Next, you need to wrap zip ties around the training bag which you will use to attach these handles to the bag. At the desired location for the handle, wrap two zip ties around the bag, the length of the handle apart from each other, but DON'T PULL THEM ALL THE WAY TIGHT. For our size of inner tube, we actually had to connect two zip ties together to get all the way around the bag. Repeat this on the other side of the bag.

Step 8: Add Secondary Handles: Part 3

Now we are ready to add the handle. Loop a 3rd (or 5th if it took you two on each handle width zip tie) zip tie through the two zip ties around the bag and through the handle. Repeat this on the other side of the bag.

Step 9: Add Secondary Handles: Part 4

It is now time to tighten the zip ties. When you are sure everything is as you'd like it, first tighten the zip ties that are going around the bag. Then tighten the zip tie that loops through the handle, but only make it so tight that you can still comfortably hold onto the handle. Finally, slide the zip tie that loops through the handle so that the extra sticks out one side. Repeat these steps on the other side of the bag.

Step 10: Cut Off Loose Ends and Tape It Up

When everything is as tight as you would like it, go ahead and cut off the extra ends of the zip ties, cutting them down to stubs. You should be able to slide the zip ties to a point where the cut end is hidden inside the handle. Finally, to avoid getting cut up by zip ties while working out, use duct tape to cover anywhere that might be a safety hazard. We covered the stubs of the zip ties that go around the bag for the handle loop to loop through. We also covered the entirety of the zip ties used to tie off the initial rolls of the ends of the bag.

You now have a completed Bulgarian training bag, congratulations!