Let's be clear ... walking the Camino is nothing like alpine mountaineering, but it ́s not a walk in the park either. Most persons with a basic level of physical fitness should be able to repeat daily Camino walking tours of up to 15 miles ( 25km ) without major problems ... even though getting a little prepared before leaving is highly recommended.
Footwear! Yes, we walk on our feet, and especially at a place like the Camino it's important to take good care of them and to find the right footwear. Water-proof walking boots are considered to be a complete solution, they keep your feet warm and dry, providing a good grip. They also support your ankles, something walking shoes cannot give you. Athletic shoes and walking sandals are not really suitable for the Camino due to limited protection and support. Feet expand during walking, and walking boots should be comfortable and a perfect fit. This can be achieved with the help of socks! Not the old ones, but thick walking socks, of which some are designed with extra padding around toes and heels. It's all about avoiding skin irritation and blisters! And if a blister has formed, despite of all the good preparation, open it carefully without removing the skin ... this is the moment to put on your quality blister plasters!
The weather on the Camino has a lot in store for us, including rainy days. That's why it is essential to bring a water-proof jacket, made of "breathable" material which extracts the moisture away from your body. Synthetic walking trousers area available in a similar range of fabrics ... look for the high tech "breathable" models, they are light, quick-drying, and the "longies" offer more protection than the short trousers.
And then there's the sun, our friend when we're on the Camino early in the morning ... but after a few hours we have been exposed all the time to UV radiation ( UVA, UVB ), so it's most important to protect our skin to avoid sunburn. It's highly recommended to put on some high SPF ( = sun protection factor ) sunscreen lotion, like SPF 30, which is widely seen as a good, all purpose choice. It's also a good idea to wear a sun hat, and there are models which come with a cape or neck protection flap.
And of course, do travel light! Bear in mind that all the stuff and things you bring needs to moved around from town to town, or carried on your back whilst on the Camino! A rucksack should not have a lot more than 10% of your body weight, or max 22lbs / 10kg. If you opt for the baggage transfer service, bring a light back-pack to carry your raingear, blister plasters, pain relieving cream etc, as well as some food and water.
Last not least, it's important to drink some water every now and then to keep hydrated ... and a little food will provide some extra energy . But when it comes to drinking, let thirst be your guide ... so, don't drink too much in order to maintain the right level of salt in your blood. And again, the Camino is not about being the fastest, being number 1 - it's about fun and having a great time with your Camino friends! Do take your time, enjoying it all with the greatest of pleasure!