The Imponderables

Running is such a simple sport, we are always told. It's just a case of putting one foot in front of the other. That's true to an extent, but beneath the serene surface we present to the outside world, we all know there's a seething ocean of worry bubbling away. Over the 13 years that Runner's World has been published in the UK, we reckon we've probably tried to answer all the questions it's possible to ask on our pet subject; from the straightforward - "What should I eat before racing?" - to the obscure - "How can I tell if the weather is likely to change?" Some themes just keep on coming up, though. Questions that never lose relevance, and always need answering. So here are the answers to the 10 questions we've all asked.

If you're a Runner's World UK magazine subscriber, you can see all 10 right here. Otherwise, enjoy these four as a preview - and if you want to subscribe, you can save 30% right here.

1. Am I too heavy to run?

In a word: no. Well, you could be in theory, but only if you need a crane and a flat-bed truck to get to the shops. Basically, if you can walk, you can run - it's just that you might be a little slow when you start and you might need to take walking breaks as you build your fitness. "The more weight you are carrying, the more load goes through your joints, particularly your knees, when running," says Nicki de Leon, a physiotherapist. "It is also more of a strain on the body's cardiovascular system."

The great thing is that, as long as you eat healthily, you will find no better way of losing weight than running: it's the most efficient calorie burner there is. You should, though, ask yourself if you actually need to lose weight at all. When assessing a person's "normality", Body Mass Index (BMI) is considered the best guide. It is calculated by dividing your body mass in kilograms by your height in metres squared (For example: 78kg/(1.83 x 1.83) = 23.3). A BMI of 19-25 is considered to be the ideal. Try this BMI calculator

2. Does it really matter what kind of shoe I buy?

Yes: the shoe that's right for you depends on your running style. If you buy the wrong shoe, there's every chance you'll endure any of a myriad of injuries, from shin splints to a misaligned pelvis, via iliotibial band sydrome and blackened toenails.

Decent running shoes have a balance of cushioning and support. There are essentially three types of shoe for the average runner: cushioning, stability and motion-control, and the wet foot test is a good way to find out what type you'll need. Put your foot in some water and stride across a paper towel, then match your foot print to the illustration it most closely resembles, and find out what type of foot you have.

The High-Arched Foot (Top)
The outside of the heel makes contact with the ground, but inward movement is minimal, so impact is concentrated on the outside part, and is not distributed efficiently. At push-off, the outside toes do the brunt of the work.
Shoe: Cushioning The extra cushioning will help absorb the impact. They're also good for lighter runners. See our cushioning shoe pages.

The Normal Foot (Middle)
The outside of the heel makes contact with the ground. The foot "rolls" slightly inward to distribute the impact. This "pronation" is critical to proper shock absorption. The foot then rolls back out on to the outside section of the forefoot.
Shoe: Stability With a good balance of cushioning and support. Also recommended for beginners or if you're increasing your mileage. See our stability shoe pages.

The Flat Foot (Bottom)
The outside of the heel hits the ground but the foot then rolls inward too much. This "overpronation" means the foot and ankle are destabilised, stressing the lower legs and the knees, causing further compensatory movements in the hips and back.
Shoe: Motion Control You need extra support and control. Also best for bigger runners who need plenty of support and durability. See our motion control shoe pages.

3. What's causing my stitch and how do I lose it?

We're all familiar with that sharp, stabbing pain at the bottom of the ribcage that comes on the run. We're all familiar, too, with contorting ourselves as we try to stretch the pain away. However, what we, and the experts, are less familiar with is precisely what causes the pain. In his seminal Lore Of Running, Dr Tim Noakes says that the most plausible theory is that the liver and other organs are connected to the diaphragm by ligaments, and that as the diaphragm rises when we breathe in, the liver jolts down as the foot hits the ground. This stretches the ligaments, causing a stitch. "The pain is exacerbated by downhill running and by fast, sustained running, as in short races." adds Noakes. On top of this, eating or drinking before exercise, lack of training, cold weather, even nervousness seem to contribute. So, it's pretty difficult to see what you can do to ensure you run without a stitch, as it were. One tip that works for many is to exhale as the foot on the opposite side to the stitch hits the ground. Stitches normally occur on the right, so this is usually the left foot. The best way to prevent the pain, though, is to breathe from the stomach, using the diaphragm, rather than the chest muscles. Try lying on your back with a book on your stomach. As you breathe in, concentrate on making the book rise.

4. When does a jogger become a runner - do I have to run a marathon?

It's a bit of a false distinction really. Very few of us can seriously claim any real excellence in our sport, and there is little difference between someone who plods round the park a couple of times a week and someone who plods round the park with a running club a couple of times a week. For many, running a race is the first time they feel a "proper" runner, but for many others this first race is the end of their running. Every year thousands of people run a big mass-participation race such as the Bupa Great North Run or the Flora London Marathon and then hang up their trainers to reflect on a mighty achievement. That's a shame, as the benefits of having trained for the race will soon be lost. Part of the problem, of course, is that a half, let alone a full marathon, is a massive effort and takes a lot of discipline and endurance, both in the training and in the racing. So once it's done, it's easy to think you can't keep it up, but you don't have to. There are plenty of short races to aim for, and they can be just as satisfying as the longer stuff. Why not pick a big local 5K or 10K? The training will be lighter, but no less rewarding, and there's far less chance of a demoralising failure on the big day. Follow a schedule and you'll have a structured programme to give your training shape and purpose, and after the race, you'll be all the more eager to pick your next challenge.