There are a lot of ways that one could compare the textile (i.e. basic) vs non-textile (i.e. fast) suit eras. For me, and the purposes of this case study, I like to think of there being four eras:

2) Non-Textile Suit (2008)
3) Non-Textile Suit (2009)
4) Textile Suit (2010+)

The reason for the granular distinction is because in 2008 the Non-Textile suits were still ‘new’ but in 2009 the science had improved and more brands (e.g. wetsuits) had entered the market.

There are a lot of ways you could approach this analysis, including taking one particular swimmer and comparing their times over each era (e.g. Paul Biedermann’s LCM 200M & 400M Freestyle), but the approach I chose to take was to compare the world records of each era on a relative percentile basis in an attempt to understand who benefited the most from the non-textile suits.

The full presentation of my analysis can be found here, but for this case study I will walk you through the analysis of two events:

1) Male LCM 200M Backstroke
2) Female LCM 200M Breaststroke

My original hypothesis were that non-textile suits give an advantage to:
1) Short-axis strokes over long-axis strokes: since non-textile suits create less drag by elevating a swimmer closer to the surface of the water, the short-axis strokes serve to benefit the most since they contain more of a glide component (breaststroke more than butterfly)
2) Women over men: women historically on average have a higher body fat percentage (roughly 15% for women compared to 10% for men)(1), therefore the non-textile suits have more drag to reduce and elevate

Case Study # 1: Analysis of Male LCM 200M Backstroke World Records
- Era 1: Ryan Lochte (March 2007): 1:54.32
- Era 2: Ryan Lochte (August 2008): 1:53.94
- Era 3: Aaron Peirsol (July 2009): 1:51.92
- Era 4: Ryan Lochte (July 2011): 1:52.96

Comparison Across Eras
-Note: a negative number means the time got faster across the era while a positive number means the time got slower
- Era 1 to Era 2: (0.332%)
- Era 2 to Era 3: (1.773%)
- Era 3 to Era 4: 0.929%
- Era 1 to Era 3: (2.099%)

Analysis
The progression of times shows us that the Male LCM 200M Backstroke definitely benefited from the non-textile suits, most notably in the third Era where Aaron Peirsol’s world record shaved over 2% off the world record he shared with Ryan Lochte at 1:54.32, the largest Era 1 to Era 3 delta across the Men’s 100 & 200 meter distances (but sixth on the list if you include women’s events).

Case Study # 2: Analysis of Female LCM 200M Breaststroke World Records
- Era 1: Leisel Jones (February 2006): 2:20.54
- Era 2: Rebecca Soni (August 2008): 2:20.22
- Era 3: Annamay Pierse (July 2009): 2:20.12
- Era 4: Rikke Pedersen (August 2013): 2:19.11

Comparison Across Eras
-Note: a negative number means the time got faster across the era while a positive number means the time got slower
- Era 1 to Era 2: (0.228%)
- Era 2 to Era 3: (0.071%)
- Era 3 to Era 4: (0.721%)
- Era 1 to Era 3: (0.299%)

Analysis
While the non-textile suits did benefit the Female LCM 200M Breaststroke, the linear decrease in world records shows us that this particular event benefited more from the swimmer themselves rather than the suit, with four different world record holders and each Era faster than the previous.

CONCLUSION
As stated in my opening remarks, there are a lot of variations one could take on this analysis, but after reviewing all the results, which can be found here, the conclusion is that women absolutely benefited more from the non-textile suits than men, but as for long-axis vs. short-axis, the data is split.

(1) ACE Fitness