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.

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.

5. Why should I join a club?

High in the mountains of Albuquerque Paula Radcliffe can be found honing her athletic powers driven by little more than a sense of destiny. Well, actually, she's driven by the encouragement of her husband, Gary Lough, as he cycles alongside, coaching her. The rest of us are unlikely to be lucky enough to have Lough in the saddle next to us, but joining a club will give you many of the benefits of having a coach, and more besides. Motivation can be about the toughest part of running. That's why the parks are packed on cold January evenings as people act on their resolutions but by the balmy evenings of July there are half as many bounding along. Join a club, and you'll have plenty of like-minded people to share your hobby with, to encourage you when you can't be bothered, to help you when you are going wrong, and to help you push yourself to discover reserves you didn't even know you had. You'll also have people to compare yourself against and to pick up tips from. "It will give you training partners, increase your motivation, add competition opportunities, and give access to advice from experienced runners and coaches, which will all add up to make you a better, stronger, faster runner," says Steve Smythe, a coach at Dulwich Runners. As if all that wasn't enough, there's also the social side of things, of which many clubs are justifiably proud. If you are worried about not being good enough to join a club, don't be: they cater for all abilities.

6. Why this chafing?

It's not pretty and it's certainly not something you'd want to discuss in the pub, but bleeding nipples can be the bain of a runner's life. Add to this the curse of blisters, sore armpits and other soreness, and you have a smorgasbord of chafing. The good news is that it's all unnecessary and relatively easy to get cure. Chafing and blisters are caused by ill-fitting, abrasive and creased clothes rubbing against the skin. So the best way to prevent these problems is to change your gear. For sore nipples and other non-foot problems, it is best to wear a thin, wicking and tight-fitting base layer, as this minimises the movement of the fabric against the skin. It is also worth trying a lubricant such as petroleum jelly on affected areas.

If you have blisters, Simon Costain, a podiatric consultant, suggests applying petroleum jelly, or covering them with Compeed (or another blister plaster). To prevent their return, you need to check that your shoes fit properly and are holding your feet securely in place - the way you lace your shoes can affect this. Another problem could be your socks. The sock rubbing against your skin can be a cause, so you need to be sure they fit properly. Some runners wear two pairs of thin socks, so the socks rub together rather than against your feet. You can even buy double-lined socks that do this, though many people find that they ruck up, which itself causes blisters.

7. What are shin splints and have I got them?

"Shin splints" is a catch-all term for pain in the front of the lower leg. Beginners often suffer from it as they are not used to the strains of running, as do experienced runners after an increase in mileage. Rest is often the best cure. If the problems return, there may be a more specific cause. It could be overpronation, which can be corrected using a motion-control shoe. It could be too much running on hard surfaces or in insufficiently cushioned shoes. A more serious problem is compartment syndrome, where the fascia - the fibrous sheath that covers the muscle - becomes detached from the muscle. Deep-tissue massage can help but, in extreme cases, surgery may be required. In any of these cases, it's common for the muscles in the lower leg to stiffen up, so stretching can help: try kneeling down with your feet together, and sit on your heels to stretch the shin area.

8. Should I stretch?

This is perhaps the most vexed question in running. Most of us were taught in school PE lessons that stretching is an essential part of an exercise routine as it will stop injuries. However, recent research has tended to suggest that it's not quite that simple. A study by a US Army research team found that recruits with the highest and lowest scores on a flexibility test were most likely to pick up injuries. They were more than twice as likely to be injured as those with average flexibility. In Runner's World last January, Amby Burfoot spoke to Dr Stephen Thacker, who had recently published a paper summarising the results of more than 100 studies. In "The Impact of Stretching on Sports Injury Risk: A Systematic Review of the Literature", Thacker found that i) stretching does increase flexibility; ii) this does not necessarily prevent injuries; iii) extreme flexibility only really helps in sports where it is needed (eg gymnastics); and iv) more injuries would be prevented by better warm-ups, strength training and balance exercises. In particular, stretching before exercise is thought to be unhelpful as it can mask muscle pain, meaning that when you should be slowing down because you can feel a strain, you will carry on and exacerbate the problem. The US Army research shows, though, that a degree of flexibility is desirable, and the best time to achieve this is after exercise, when the muscles are warm and flexible. To avoid the risk of injury, don't hold stretches, but move into and out of them in one motion.

9. How much cross-training will make up for missing out on a run?

Cross-training has long been recommended as a way to stay fit when you are injured, but it is also increasingly used as a replacement for running to help avoid injury. Two members of our team are training for the Flora London Marathon using cross-training as regular parts of their programme. The trouble is that it's difficult to know what exercises are best for you as a runner. In order of specificity, the following are the activities that will best complement your running:

      1. Elliptical trainer
      2. Aqua-jogging
      3. Cross-country ski machine
      4. Step machine
      5. Stationary bicycle
      6. Rowing machine
Each of these takes a different level of effort, and it can be difficult to gauge how much work you have done. At, you can generate a list of the calories you will burn in a multitude of activities, from calisthenics to archery, via the more useful rowing and elliptical training. For example, a 76kg man will burn around 1,150kcal in an hour of 8.5-minute miling. For the same energy expenditure, he will need to do: 1 hour 36 minutes elliptical training; 1:24 aqua-jogging; 1:36 on a ski machine; 1:15 on a step machine; 1:36 on an exercise bike; and 1:36 on a rowing machine.

10. I need strong legs for running, why should I work on my upper body?

There's no doubt that your legs are your main priority when it comes to running, and that regular resistance sessions reach the parts that running can't. Your upper body, however, needs to be strong too if you are to maintain the good form that is vital to running well. "Running faster is easier if your whole body is working with you," says RW Coaching Editor, Bud Baldaro. "A runner with strong legs but weak arms and core muscles is always slower than one with total-body fitness." The trick to weight-training for runners is to do exercises specific to running. That means avoiding, for example, heavyweight bicep curls, but trying an exercise that works your core muscles - stomach and back - at the same time as your biceps. You don't have to avoid heavier weights, but you do need to make your exercises work your core, so free weights are preferable to fixed as these exercises force you to use your whole body to maintain balance. Building up excess muscle that has you looking like Mr Universe won't help, but building lean muscle will make you a faster runner.