The most important thing is the safety of both of you, and welfare of the dog. 

Firstly lets look at how to stay attached to the dog. Canicross harnesses are designed to allow the dog to pull comfortably. They don't go across the chest, but instead pass through the legs, and come up in a Y-shape. This means there's no pressure on the shoulders, nor is it pulling on the windpipe. There's many brands of canicross harness, but 2 styles, long or short. Both have advantages and disadvantages, which can be discussed in depth on a taster.

Now what not to do. 

Running on a collar. This pulls on the dogs windpipe, you can't expect your dog to run whilst being asphyxiated, and long term pulling on the neck can cause injuries. I hear people say it doesn't matter, as their dog doesn't pull. If pulling meant I strangled myself, I wouldn't pull either. 

Halti's. These are a training aid, designed to stop pulling, and pulling is exactly what we want in canicross. Shockingly however people think it's ok to run with them, thinking it keeps the dog under control. It will, because the neck is being wrenched round at such an angle, that the dog is in far too much pain to not be. 

Poorly designed harnesses. Harnesses that go across the chest, such as julius K9, are fasion items, and have no place on a canicross dog, or any dog for that matter. There's plenty of videos online showing this harnesses impeding the shoulders and really affecting the gait of a dog. Long term use can cause joint and mobility issues. Other occasions you see poorly fitting examples that slide up the dogs chest, and pull on the throat, the same way a collar does.

Next up, is how to connect the dogs harness to yourself. We use bungee lines, as these soak up any shock incurred when a dog accelerates faster than us, and pulls the line tight. With a solid line, this would cause a jolt that could injure, you, the dog, or both.

Canicross belts. These belts sit on your hips, like a climbers harness. The allow the dog to pull through the hips, ergonomically and comfortably pulling you forward. 

Cheaper options offer waist bands, which wrap around your waist. Whilst these are ok, and are allowed in canicross events, once a dog starts pulling, you'll find the pressure is all taken up in your lower spine, which is much more uncomfortable than a hip

Handheld leads. 

Simply, you're being pulled from a taller position, leading to the pull being downward, more than forward, which will increase the likeliness of being pulled over which is why many, wrongly, feel the solution is a halti, as they try to stop the pull in order to feel safe. A good dog is like a spotter in the gym, and can take over 2 minutes off a 5k run. why would you stop the assistance, when the kit is there to achieve it safely, and without causing pain to your dog? 

On top of this, should you loose balance, when running handheld, it's likely that you'll let go of the lead, and have a loose dog.

Lastly, terrain. we run off road, as it's better for a dogs legs and joints. 

Never do prolonged runs on tarmac. Road running shoes come with thick cushioning, to protect us from shin splints or joint issues, dogs paws don't have any cushioning. Dogs legs aren't designed for the shock from running on tarmac, and to bare paws, it's like running on sandpaper. Short term, the dog will be in pain, long term you're causing joint and mobility issues in later life. 

We do accept that some trails and footpaths may require short stretches of road to connect them, so as a rule, we say max 10% of a run maybe road, but ideally none of it is.