Incorporating strength training
Adding a well rounded strength training program to your plan is a smart move if performance is a goal. Strength training will help to keep you injury-free, since your ligaments and muscles will be better able to support the stress you place on them, and it will also help you work at a higher level of intensity, thus increasing the level of your workout. If you have any muscular imbalances (outer quad is stronger than inner for example), you will also want to assess this and find ways to correct it with your strength training. Doing so will prevent you from experiencing many troubles down the road.
The major lifts you definitely need to be doing are squats, hamstring curls, the bench press, military presses, dead lifts, and some type of abdominal core work. These particular muscles are heavily used during your cycling training, so strengthening them is important.
Utilizing hill sessions
Another type of workout you might consider doing as part of your cycling training is a hill workout. These are especially good for building quad strength and increasing your ability to utilize oxygen. Try to find a course that is, for the most part, uphill, but be sure to start out gradually in terms of distance covered, as you will likely be very sore after these sessions. Once you get really good, you can start doing sprint sessions on hilly terrain.
If you have decided that you are going to train for a particular cycling race, be it a triathlon or otherwise, you will want to begin to tailor your workouts to the race. Try to include more sessions of approximately the same distance that you will be racing, and if you can get your hands on information about what the course is like, find a similar course to train on. It is particularly important to take note of altitude at this point. If you are going to be racing at a considerably different altitude than you are used to, you will definitely want to factor this into your training. The higher up you go, the harder it will be on your muscles (due to decreased oxygen available to the body).
As with any workout, you must factor proper nutrition in with your training. On longer-duration, moderately paced sessions, you will be able to predominately use fat for fuel, so it is not entirely necessary to be eating a high-carbohydrate meal before. That said, if you are cycling for one or more hours at a time, you will likely find that your performance will be better if you do eat some carbohydrates, either before the session or partway through, in order to give your muscles their preferred source of fuel (the body burns carbs more easily than fat).
If you are performing a sprinting session, however, be aware that your body can only use carbohydrates during this type of activity due to the nature of the energy system, and, therefore, it is essential that you include carbohydrates in a pre-workout meal.
Finally, you must take hydration into account, because even a slight amount of dehydration can cause you to feel fatigued and become dizzy, with a drastic impact on how effectively your muscles function. On longer bike rides, be sure to bring a water bottle filled with water or an electrolyte-balancing solution that will replenish your water stores as well as your potassium and sodium levels (for those who sweat a great deal during their workouts, an electrolyte solution is preferable).
roll with it
If you are looking for a new challenge to take on this summer, give cycling a try. There are many health benefits, and it is a great way to push your body past any plateaus you may be experiencing. Just ensure that you approach your training in a smart way in order to reap the greatest rewards from the time you dedicate to your sessions.