There are two types of thinking when it comes to training and racing effort.
One method is to train hard to race easy. Multiple Ironman Triathlon World Champion, Peter Reid, once said that he would train so much and with such an effort that he could win races with ease, because he hated hurting in a race.
To make a race easier, take difficult characteristics of a goal event and train through more difficult scenarios. 2006 Boston Marathon champion Rita Jeptoo said "I trained in Iten where it is very hilly, so in Boston the hills did not feel like anything at all."
You can also use your key workouts to make the races feel much easier. 2012 USA World Team (Indoor 800m) member Tevan Everett said, "The workouts during my off race weeks are becoming race pace but in interval formation. Nowadays I often look forward to racing because it’s much easier than training." This not only makes his training more race specific, but it also turns the race into something more manageable. He trains farther and harder than he races!
Peter Reid would occasionally eat spicy salsa with nachos prior to workouts with the purpose of upsetting his stomach during a run. He would train through the discomfort because he knew he could potentially experience similar feelings while racing. He knew he successfully dealt with it while training, so he could better handle it while racing!
Tour de France winner Bradley Wiggins has discussed his time training on Pico del Tenerife, one of Europe's highest volcanoes. "There is no such thing as an easy Tour but we have done days or sessions up here that are hard as anything I have ever done. When you start banking those rides one after another and feeling the benefit, it is a huge confidence boost, I would be very surprised if there is a day in my next race – defending my Dauphiné title – that will match the big days we have done on Teide."
Racing to your limit is another approach. Made famous by the late Steve Prefontaine, he said "The only good pace is suicide pace, and today is a good day to die." Not better or worse than training hard to race easy. Some athletes out there really wish to suffer and race as hard as mentally possible. Prefontaine showed this time and time again. During his greatest race, the 5000 meter Olympic event in 1972, he raced for the win by leading the final mile at 4:04 pace. He said that if anyone is going to beat him, they would have to bleed to do it, and he really made his competitors suffer.
While Ironman World Champion Peter Reid said he hated pain while racing, he has also been quoted as saying that he wished to race Ironman with such intensity that he would black out at the finish line!
Yuki Kawauchi, a Japanese 10,000m and marathon national record holder, has done just that. "Every time I run, it's with the mindset that if I die at this race, it's OK." He has visited the medical tent after marathons more often than not. He races with such intensity that he has even suffered from memory loss. At the 2011 Tokyo Marathon, he passed out at the finish, not remembering anything after 39k!
Picking one method is of course not necessary or even recommended. As with all good things, they should not be taken to an extreme or absolute. Both philosophies have excellent points that can be taken. Use the time before an event to teach your body and mind what it is capable of. Experience some discomfort while training so while racing, you are not in new territory if you should experience the same feelings. It is said to never try anything new on race day. This generally applies to gear and nutrition, but should also apply to effort and feelings. Spending time training hard teaches the mind that being at "suicide pace" is acceptable and allows this to more easily occur. If a runner never approaches their limit while training, should they ever expect to approach their true limit while racing?
What are your thoughts? Do you tend to think one way or the other?