1) Low Wall - Train your quads and calves. Also condition your adductors to be able to have a good stretch and mobility 2) High Wall - Build on upper body strength, especially the deltoids, trapezius, pectorals. Once on top, keep your frame low to minimise risks from accidental fall. Rely more on technique than strength and trail shoes makes a difference.
3) Crawls - Use forearms and shoulders, with the aid of your toes, to propel you forward. This is more energy-efficient than standard leopard crawls and is better than rolling because that only makes you dizzy w/o actually helping you conserve energy. A strong core would really help with this.
4) Atlas Stone & Tyre Flips - Adopt proper lifting techniques. Otherwise you stand a high chance of injuring your back.
5) Chained Block - Keep a short leash and don't stop once you move. Letting the leash extend long or stopping often only allows the block to drag more earth and adds resistance, thereby slowing you down.
6) Hoist - Pull, anchor and keep pulling. Capitalize on the momentum. Stopping midway means straining your arms with the weight more than necessary. Don't wind your arms around rope either, because if your muscles tire the counter-pull of the rope might dislocate your elbow or shoulder .
7) Vertical Rope - Train your core, upper body and technique. When your body is fully extended, hug the rope close to streamline your CG. If you are tired, establish a firm foot lock and squat fully without leaning back. A semi-extended posture will only tire your limbs double-time. Gloves are subjective
8) Gravel bucket - Proper lifting techniques. Scuttle fast to cover more distance and reduce fatigue. Gloves are great to protect your fingers as you load the gravel and when corners of the bucket with all that weight bears down on the fingers.
9) Z Traverse - Train your finger grip and keep your frame close to the wall. Gloves are subjective
10) Tyrolean Traverse - is all about technique. Going over is energy-efficient for long traverse (anything more than 20m). Going under is more energy-efficient for short traverse. Either over or under, strength only gets you so far.
11) Sloped rope - Identify rope's anchor point. If it is beyond the peak, just pull your way up. If before peak, transfer quickly once you let go of the rope and make sure your shoulders get over the peak. Keep perpendicular to the wall as you climb.
12) Mud pits - Find footholds or create some. Balancing your CG on the upper body helps. Think physics helped by physique.
13) Monkey bars - There can be a variety of combinations. Best to train upper body, including forearms, and figure out the techniques required for each different part of it before attempting. Fully extending your arms are likely to guarantee a quick slip.
14) Cargo Net - Grab the cross sections where the horizontal and vertical connects. This is because those will not sag like the horizontal and provides more surface area for a handhold than the vertical. If you place your hand on the horizontal, someone might just step on it.
There are many more obstacles a race can throw at you and this list is not exhaustive. But the biggest obstacle most people face is CONFIDENCE. Some have very little, some has too much. Either way, the answer is in training.