It was found that from pre-test to post-test mean improvement was decreasing their 400m times by 10.53 seconds. However, there were only 8 participants so it wasn’t very reliable. It was done on participants aged 15-16 who are potential Olympians. The method of training used was interval training in three phases. Phase one used basic endurance, phase two used anaerobic threshold endurance training and phases three used overload endurance training.
Swimming.org (2012) proposed a swimming set that can improve speed endurance. The Interval set was 20x50m with a 15 second rest after each 50m. However, there are no results on whether this did improve speed endurance or not and is therefore not reliable. Though this should be valid as it was taken from the governing body of swimming; the ASA.
A typical Interval session would consist of 5-7 repetitions with about 2-3 minutes recovery- Momentum sport (2012.) Tanaka et al (1998) disagreed with this and proposed strength training should be done in lieu of