This is an article by one of the Carmichael Training Systems cycling coaches.
Subject: Step Away From The Bicycle
By Jim Rutberg
Logic says that the harder you work, the better you get. The harder you push youself, the faster you become. That logic is correct for students and businessmen, but only partially correct for athletes. Rest, in adequate amounts and at the right times, is essential for athletic success.
Training is a balance between stress and rest. Your body adapts to the stresses forced upon it. When you stress your aerobic system, it gets stronger in order to better cope with that stress. When you perform weight-bearing exercises, the structure of your bones changes so they can support more weight. These adaptations only occur when the body is given sufficient recovery time between workouts. Recovery time is necessary for repairing cell damage, building new cells, replenishing fuels, and rehydrating.
"I'll get plenty of rest when I'm dead." Fine, ride yourself into the ground day after day and let's see what happens. For the first few weeks you get faster and stronger. As a result you work even harder and ride even faster. After a while you get to the point where you are not getting any stronger or faster, but you keep working as hard or harder than ever. Soon the harder you push the slower you go and your exercise heart rates start to fall. Even your maximal effort does not make your heart rate climb. You can't sleep. Your poor performance on your bike translates to a foul mood off the bike; you're a real joy to be around. When you finally get so run down that you get sick, you might finally take enough time off to regain your senses, and hopefully your friends.
During those first few weeks of hard training, your body was overworked and under-rested, but it tried to adapt to deal with the workload. The period of time when the training was not leading to adaptations and improved performance was the period when your body was recovering just enough to repair damage and replenish fuels. When the balance tipped so that you could no longer adequately repair the damage from each day's training, your performance started to nosedive. From this point further, every workout you did added to the problem until your body was so tired from repairing an ever-increasing amount of damage that you failed to fight off an infection.
Rest. Take at least one day a week completely off and incorporate active rest into your program. Active rest, in the form of slow recovery rides or other light aerobic exercises, facilitates recovery by increasing circulation to flush wastes and bring in nutrients. Carmichael Training Systems coaches often utilize a three-week building phase followed by one regeneration week. Each building phase targets a specific energy system or skill. Rest is incorporated into the building phase so that fatigue does not impede progress, but it is the regeneration week which provides the rest, repair, and complete replenishment necessary for real improvement.
