For years, coaches, physiologists and Joe Blow on the internet have been discussing the best training methods. Some have argued for the primacy of the base. Everything revolves around the base, or LSD (long-slow-distance) training session. Miles and miles of “easy” riding are prescribed before and more intense sessions are allowed. Others have argued that LSD training primarily trains you to go long distances slowly, and that to improve your race performance you need to train faster, and sooner rather than later.

Both approaches make sense in their own way. Building base before doing hard workouts makes sense in that you theoretically are allowing your body to get stronger before really stressing it. This is related to the concept of periodization: you vary intensity and distances based on time of year, build in preparation for racing, and do the most intense work as sharpening just before races. On the other hand, there are people who advocate something called reverse-periodization. The theory goes like this: since the adaptation to the hard stuff happens quickly, you do that earlier in the training, and do more specific workouts as the race approaches. For example, if training for a marathon, you would work on intense stuff early on and then put it into a maintenance phase for the rest of the season. You then build your long runs, and as the race approaches you do as much training as possible at race pace, which is going to be a lot slower than your typical intense workout. This makes sense as well: why do intense training to sharpen if you will never run near that speed on race day? Isn’t it better to gain whatever you can from intensity early on, and hammer on what you need to do in the race?

An important question to ask is just how much "intense" training is necessary to see the results we desire. Unfortunately, there isn't a hard and fast answer here. However, in a 2005 issue of Medicine and Science in Sports and Exercise, a group looks at the correlation between (what amounts to) LSD training, and faster training when athletes ran 4 or 10k cross-country races. What they find is a significant correlation between low intensity (below approximately 70% HRmax / 60% VO2max) workouts and high intensity race performance in runners. Furthermore, they find no correlation between higher intensity training (i.e. at 60-85% VO2max or >85% VO2max) and race performance.

I wondered about this, and so started looking back at some of the studies I read while writing my book. I realized that while some of them show greater improvements in VO2max with more intense training than with easy training, they did not look at race performance. I was wrongly assuming a standard correlation between the two. (In other studies, this correlation does exist in some studies; I was just surprised it was not more ubiquitous.) Also, it should be remembered that while VO2max sets the ultimate limit on aerobic ability, the percentage of that ultimate ability you can maintain for any significant period of time is highly correlated with the LT, or lactate threshold. Therefore, we could consider the possibility that all that mileage at probably sub-threshold pace has served to elevate the lactate threshold, and that this is more important and more easily detectable than the benefits of more intense training.

Yet, physiology teaches us that specificity in training is paramount, so why should training at specific race intensity not improve performance on race day? The authors comment that the statistics used do not imply a cause and effect relationship. To prove cause and effect, you’d need an interventional study. You would need to collect runners, make some run lots of LSD and some run less LSD, and see who did better in a race. (You’d also need a lot of runners.) They also comment that high intensity exercise may simply be of general benefit, and the response may be very easily realized. In other words, a little goes a long way. Finally, the authors suggest that chronic hard training might lead to a reduced response of the body to catecholamines (i.e. stress hormones like epinephrine), and therefore a reduced ability to selectively send blood to working muscle in a race.

I still find myself sitting on the fence where all this is concerned and I would be cautious about drawing too many conclusions unless I saw a good interventional study. For example, LSD training honestly doesn’t seem to work for everyone. There are examples in the cross country skiing literature from a guy named Gaskill showing that skiers who did not respond well to primarily distance training significantly improved when given a diet of higher intensity training. Also, I have worked with athletes who just break down under high mileage, but have great performances when they cut down the distance and add more intensity.

At the end of the day, the balance of LSD versus intensity seems to be a very individualized one, and needs to be made by athletes and coaches on a case by case basis. Experiment, and see what works for you! You may bring yourself to a whole new level of performance by thinking outside the box and looking at your training logs with a critical eye.

References:

Esteve-Lanao et al. How do endurance runners actually train? Relationship with competition performance. Med. Sci. Sports Exerc. 37(3): 496-504. 2005.