I am in no way qualified to give medical advice. I have no experience as a trainer. The following information is based on my personal experience.
On my last trip, several people asked me if you have to train in order to go on a multi-day bike tour. While I'm sure this can improve your comfort and performance, I don't think that it is necessary. A tour is not a race. Be willing to go as slow as you need to.
In other words, if you want to start touring, start. Training can be a form of procrastination. Although I was comfortable with a 40-60 mile trip before my first multi-day bike tour, these were leisurely rides. If you're not enjoying yourself, you're pushing too hard.
Before you embark on a multi-day bike trip, you should give your bike, clothing, and equipment a realistic test. Set up as you would for your tour, and bike at least 40 miles. Any physical ailments you notice will be exacerbated as days pass on the road. Look for the following:
Shortness of breath, chest tightness. Ignoring this is what cut my Grand Illinois Trail ride short. (Well, that and knowing the worst hills were directly ahead.) Shortness of breath does not necessarily mean you're just not in good shape-- it can be exercise-related asthma. Asthma that is triggered by allergens or polluted air can get progressively worse after multiple days of exposure. I felt kind of like my cat was sitting on my chest, only she'd gained 100 pounds and I was sitting up. For this, you absolutely need to see a doctor. (I bought some Primatene Mist on my ride and it helped very little; Sudafed helped more. Anyway, I'm seeing a doctor.)
Pain, tingling, or numbness in fingers or wrists. If this is an issue, you need to move your hands around more on the bike. If your handlebars only allow one position, get aero bars or other alternate handlebar positions installed. Buy padded bike gloves. Try not to bend your wrists as you put weight on them.
Chafing on the seat. Just a little bit of chafing in one day can develop into skin that gets rubbed through, ingrown hairs, and saddle sores (deep, painful cysts) over multiple days. If this is an issue, make sure you're wearing real biking shorts or pants (and you don't wear underwear with those, you know.) Your bike seat is very important as well. Although it may be tempting to buy the biggest seat you can find, this can cause chafing across a larger surface of your rear. Read reviews of bike seats and find one that minimizes chafing. If possible, buy from a bike shop where you can talk to a knowledgable salesperson about what seats are best for your shape, and where you can return the seat if it's painful. If you're using the seat that came with your bike, you can probably get something more comfortable.
- Bicycling Magazine's Gear Review Finder
- Amazon Reviews (I don't recommend the cheap brands like Bell for something this important)
Purchase an athletic lubricant such as Body Glide to treat the chafing areas. Another alternative is to go with a recumbant bike. These can be difficult to use in traffic, but they're great on bike trails, and they do save your butt.
Knee pain. This can mean two things; your seat is at the wrong height (probably too low), and you are doing too much pedaling in a high gear. Adjust your seat so that your knees are not bent more than a 90 degree angle (you can also get this checked in a good bike shop) and use your lower (easier) gears. Pedaling more easier strokes is better for your knees and your heart.
Back pain. Really excellent, in shape cyclists develop their abdominal muscles so that their abdominal muscles are supporting their torsos rather than just their back muscles. Doing situps and crunches will help with this. The other thing that helps is getting a bike with shocks under the seat and over the wheels. Let the bike absorb the shocks rather than your back.
Sunburn. Wear sunscreen and sunglasses. Wear a helmet with a visor.
Sunscreen and sweat in your eyes. I wear a rolled up handkerchief on my forehead. Before I did this, I would be blinded by stinging salt and sunscreen in my eyes about an hour into any given ride.
Nausea, headache, thirst. You may be dehydrated. If you noticed (perhaps even with delight at the convenience) that you did not have to stop to relieve yourself for the last three hours, you probably are. Drink lots of water. If it is a hot day or you are sweating a lot, drink an electrolyte sports drink (like Gatorade.) Make having water a priority; don't put it off for a few more miles, and always have a full bottle available. Dehydration can also make you painfully constipated. You may want to carry a stool softener (not a cramp-inducing laxative) in case this happens.
Quad pain (tops of thighs). That's the good pain! Actual muscle pain! Hot baths and ibuprofin are good to help minimize it. The danger is working your muscles to such an extent that you won't want to get on the bike the next day. So back off a little. You can also use toe baskets on your pedals, so that you can use the opposing muscles to lift the pedals back up. You can use cycling shoes and toe clips as well, but I would never wear shoes out cycling that I would not be willing to walk ten miles in, just in case something unfixable happens to my bike.
Get a Tune-up
Before you go on a multi-day ride, get your bike tuned up at a good shop. I go to Mikes Bike Shop in Palatine, Illinois. Even though I no longer live in the suburbs, I make the trek from Chicago. This is a great shop with competent, helpful people, and a center of cycling activism.
Tell the person who will be working on your bike that you are planning to go on a multiday ride, and point out anything that you think may need to be adjusted or replaced. How old are your innertubes? How old is your chain?
Wayne Mikes of Mikes Bike Shop also recommends that you get your bike fitted at a bike shop. Arrange to do this when you pick up your bike. Getting your bike fitted (largely the arrangement of the seat and handlebars) can prevent or minimize many potential bike pains.
Don't Get Flats
I cannot recommend Mr. Tuffy strips highly enough. These are hard plastic strips that are installed between your tire and your innertube. I bought a set when I got my bike about six years ago, and I have not had a puncture flat since. I still have to look out for leaks that form around the valve from when the valve scrapes against the rim, but I have never been stranded due to a puncture. You can take this as further evidence that I don't care how fast I ride; increased weight under your tires will make your bike a little slower.
Update: recently, several bike store mechanics tried to convince me to throw out my Mr. Tuffy strips. They told me that if your tires get just a little bit underinflated, your inner tube can get pinched between the strip and the tire and pop. This hasn't reflected my experience yet, but they also suggested that the safer bet is to buy a new kind of puncture-proof tire and avoid the strip. I plan to try this as soon as I can afford it.
Know How to Change a Tire
Even Mr. Tuffy strips aren't perfect. (Actually they are, but if you rely on them completely and can't change a tire, lightning will strike your innertube.) Carry a spare innertube, patches, tire levers, and pump, and know how to use them. Make sure that you partially inflate the innertube and check for pinches and alignment before you fully inflate it-- I can tell you a funny story about what happens if you don't. I prefer to carry an innertube rather than patches because it can be really hard to find the leak in a punctured tube.