The one thing successful 400m athletes have in common is that they have to be aggressive and tough. But there are great extremes of variety in the way that 400m athletes can be prepared. Athletes can be 200/400m types such as 2000 Olympic Champions Cathy Freeman or 1996 Champion Michael Johnson and 2016 World record holder Wayde Van Niekerk or 400/800m types like Jearl Miles-Clark or Alberto Juantorena. Some also may be pure 400m specialists with balanced ability over 200m & 800m like maybe Anna Guevara or Felix Sanchez.
Athletes when racing the 400m event need to be able to run at a high percentage of their maximum speed for a prolonged period. A pace analysis of the World Championships in 1999 showed that Michael Johnson’s maximum average speed over 50m was 10.09 m/s where the maximum speed reached by Maurice Greene in the 200m was 11.09 m/s & in 100m was 11.90 m/s. This means that Michael Johnson needed to use over 85% of his maximum speed during a 400m race and he was still running at an average of 9.54 m/s between 200m & 300m. This is still over 80% of his maximum velocity. Improving maximum speed in any athlete can improve their ability to maintain speed in a 400m because they will have more speed in reserve. However maximum speed training comes with a greater risk of injury than slower endurance work. Maximum speed training is also much more taxing on the nervous system producing flatness that can effect the quality of sessions that follow in at least the next 48hrs.
There is however, much more to improving the ease of an athletes speed than expanding maximum speed. Many 400m athletes tend to have longer strides coming from more power. This means they tend to get more of their speed from stride length rather than high stride rates. This makes sense scientifically as high stride frequencies will be more taxing on the nervous system and may require more energy especially from the upper body which will be more difficult to relax at higher rates. Stride length can be improved in a variety of ways by the smart use of weight training, plyometrics & hills.
Some may argue that Michael Johnson is a big exception to the theory of 400m athletes focusing on stride length. Michael Johnson tended to maintain very high stride frequencies throughout the entire 400m event. He did this by having exceptionally short contact times with the track and probably by doing so was able to lose less energy on each impact than the other athletes. Michael Johnson also had a surprizingly long stride which came from extremely high levels of power.
Minimizing wasted energy due to over-striding is worth working on with any athlete. Over-striding occurs when athletes contact the ground too far forward. Over-striding results in a jolt through the body that can cause injury and results in an excessive loss of momentum during the first instant of ground contact. One simple way to decrease over-striding is to find a slight downhill slope and have the athlete run down it aiming to run smoothly by minimizing the feeling of impacts that occur. This can be achieved by intentionally aiming to contact the ground further under the body. The effect of over-striding will be magnified for the athlete & they will easily be able to learn how to adjust the position of contact in a way that has the desired effect. They should do maybe 2 sets of 3 x 50m hills with 2 runs on the flat after each set. Doing this simple session regularly should produce a noticeable decrease in the extent of over-striding. The most common time for an athlete to over-stride is at the end of a 400m race so it is worth doing some work on the track when fatigued to optimize the athlete’s ability to finish most effectively.
Developing high levels of endurance is very important for the 400m event but it is essential that it be based on developing endurance of race speed. The ability to be able to run the first 200m fast & be able to not blow up in the closing stages is very much related to the amount of speed the athlete has in reserve in the first 200m and then the speed endurance to maintain a high percentage of that pace. Endurance that is developed at slower paces uses different running biomechanics & is limited in its transfer to the 400m race. General conditioning is of great value but is essential to perform appropriate specific work at the right pace & also simulating conditions of race like fatigue. 800m athletes have highly developed speed endurance at their race pace but if you put them in a 400m without specific race pace work & without having them race some 200m events. Then their performance at 400m will likely be below what is expected. They also will have a weakness in being able to compete against 200m types in an aggressive race. The faster 200m type athletes will often blast the first half of the race & blow up in the final straight. 800m type athletes would be expected to finish strongly but since they are slower in maximum speed capacity they are more fatigued by the fast early pace & often waste their finishing advantage in trying to stay with the faster 200m type athletes early in race. This fact suggests that the best type of athlete to be is the 200m type athlete as it presents them with more options in terms of pacing the race.
An important exception to the event favoring 200m type athlete is when the athletes need to race in major championships and endure up to 4 rounds of competition. This situation rewards the athlete with the best ability to back up. Less well conditioned athletes will struggle both in terms of physiological performance deterioration & with having legs that are sore. The best way to avoid these problems is by making sure the athletes have built a bigger base with higher volumes of training. There are many athletes from a 200m background who can run a brilliant single 400m race with minimal training. But if you try to get them to race multiple races in a major championship they are often so sore the day after a fast race that there is no way they can excel in major championships.
There are many varieties of speed endurance training. It is important to train with a balance of the different varieties. It is not near as simple as just running at race pace with short rests until highly fatigued & expecting optimal gains in performance. My preferred method is to improve biomechanics and ease of race speed first. This is done with tempo runs at race pace performed with low levels of accumulated fatigue as well as maximum effort acceleration work over 30-40m. The athletes can then expand how far they can sustain 400m race speed by performing longer repetitions with longer rests. This works at boosting the amount of energy supplied by the Lactic Anaerobic system. Then the athlete can work at maintaining running speed when experiencing high levels of acidosis. This is best done in low key races & with smart use of lactic tolerance work at training. Lactic tolerance training is typically fast short repetitions with short rests. It is often over used with athletes & can produce rapid gains initially but it should be regarded as the icing on the cake.