I've have posted most of this before so I hope that I don't bore everyone.
Let me explain my school's conditioning drills. This came about with complaints that it is hard to find the time to condition as much as we wanted to and practice kicks as much as we wanted to. We decided to combine the two things and we have added and added ....
We do the drill with three to six people in a triangle or circle. Four people is best. This way you can watch each others technique and get feed back by having your technique observed. (Four people gives you a little break).
All these drills start in the left stance going around one way and then the right stance going back the other way. This way you still get to kick the two guys kicking you. All series of kicks are done five times around on each side. All kicks (except one) are delivered to the front leg.
After each kick, except for the front kicks and side kicks, the receiver punches to the deliverer's body . (For the front and side kicks, if the guy is still close enough to hit you, then either he is new and you are being nice, or your not kicking hard enough.) Really helps you keep the breathing in place at all times. If you want to add a little spice throw a second punch in. In the end you do about 170 kicks and 150 punches (plus any doubled ones). The purpose of this is to train you to strike back the moment you are hit.
1) Rear Leg Front kick: The first kick is mid-level or slightly lower. The receiver raises their leg in a crane block. The kicker delivers the kick to the shin. The kicker then kicks the receiver's thigh, and then kicks the receiver in the stomach. (Toe kicks are used by those who can deliver them to those who can take them.)
2) Rear Leg Roundhouse kick: The first roundhouse is blocked by the receiver with a crane block. (They can turn the shin out if both parties don't mind). The second is delivered to the receiver's thigh. The receiver then raises there arm so that they can be kicked up into the ribs. The fourth kick (the only drill with four kicks) is thrown at the head. The receiver can challenge it with their forearm, but it is better to practice a dead arm block that absorbs the power. Don't forget to punch back.
3) Rear Leg Side Kicks: The first round house is blocked by the receiver with a crane block (the kick is delivered directly on the shin). The second is delivered down onto the thigh of the receiver. The third is delivered into the receiver's stomach. You will quickly discover the heel is the best part of the foor to kick with.
4) Lead Leg Roundhouse Kick: (No crane block by the receiver) The first kick goes to the inside shin, the second the inside thigh and the third to the midsection (again, as conditioning is the aim, you need to raise your arms to give the target). (We have found that, to start, it is best to turn the body towards the kick slightly, so that the kick comes up into the stomach and not the floating rib.) Don't forget to punch back.
5) Combination: No movement by the receiver. The first kick is a rear leg roundhouse to the receiver's outer thigh, do not draw the leg back but place it down close to the receiver. The second kick is an oblique kick (instep kick) delivered with the toes turned outward. This goes to the inside thigh of the receiver's rear leg. The last kick is a front leg side kick to the receiver's stomach. Don't forget to punch back on the first two kicks.
6) Forearm Drill: The receiver has their hands up by their head in a protective position. The deliverer swings both a left and a right inside forearm strikes at their head. The receiver blocks these with their outer forearm. After the last block strike (NO CONTACT) to the deliverer's head. (While technically it is the same drill you can choose to do these both ways like the kicks)
7) Regular Kota Kitia.
If you need more body conditioning, although I would doubt it, or if you only have a little time and want to work the body, try this one:
Extra Body conditioning: Described with a left kick starting, reverse for the other direction. The deliverer kicks the receiver's outer thigh as they place their foot close to the receiver in a right sanchin stance they deliver an downward strike to the receiver's solar plexus. By pivoting from the right Sanchin stance into a left sanchin they use mass to deliver right uppercut into the receiver's left side of their stomach. They pivot back into to a right Sanchin to deliver a left upper cut into the receiver's right side of their stomach. They pivot again to deliver a downward right hand strike to the upper chest. They pivot a final time to deliver a downward left hand strike to the other side of the upper chest. (Going lighter when striking over the heart.)
A couple of really important points is to have everyone leave their egos at the door and LAUGH a lot! Ya gotta have fun with it.
While this works on your conditioning it really works on your ability to strike.
P.S. One good hard run through each week is enough.