How does a wetsuit affect your paddling?

A 2015 study by Jeff Nessler and colleagues at Cal State San Marcos investigated how wetsuits affect our paddling mechanics. While thicker suits like 8mm clearly restrict movement, the impact of standard Southern California 3/2s and 4/3s remained unclear. The researchers wondered: does neoprene help by increasing body awareness, or hinder by adding resistance?

Their experiment centered on a, let’s say, creative setup - a surfboard mounted to a rowing machine. Twelve male surfers donned a 2mm wetsuit top equipped with lights for motion-tracking. The rowing machine provided water-like resistance while instruments measured heart rate, skin temperature, and oxygen consumption. Electrodes monitored muscle activation throughout their 5-minute paddling sessions, both with and without the wetsuit. The electromyography (EMG) machine tracked which muscles fired and when, giving detailed insight into the paddling mechanics.

The setup, very creative and coming to a gym bro near you. This is Figure 1 of the paper.

The results revealed subtle but significant changes. Wetsuit-equipped surfers showed deeper, more variable paddle strokes without altering stroke length or timing. The researchers quantified this using "Approximate Entropy" - essentially a measure of stroke complexity that helped them understand how consistently the surfers were paddling. While oxygen consumption stayed constant between conditions, skin temperature predictably rose when wearing the wetsuit.

Most muscles worked equally hard regardless of attire, with one exception: the middle deltoid in the shoulder increased activity when paddling in neoprene. The data showed the latissimus dorsi and triceps brachii muscles powered the middle of each stroke, which makes sense given these are the primary pulling muscles in swimming motions. Interestingly, the lats displayed a different firing pattern with the wetsuit - engaging longer but less intensely during each stroke. Although this wasn’t addressed directly in the paper, this suggests the neoprene might be helping distribute the workload more evenly throughout the paddle motion.

These are the muscle activation energies as a function of stroke cycle. The hands enter the water at about 20% and are straight down in the water at about 50% of the cycle. Dark is with wetsuit, light is without. This is Figure 5 of the paper.

The wetsuit appeared to enhance proprioception - that sense of where your body is in space. The tactile feedback from the neoprene led surfers to dig deeper without burning extra energy. Only that single shoulder muscle had to work harder to overcome the suit's resistance. This finding challenges the assumption that wetsuits universally increase paddling difficulty.

Keep in mind, this was all measured on a board strapped to a rowing machine, in a dry wetsuit in a lab environment. How this translates to the ocean, or even to thicker wetsuits like a 4/3 is undetermined. Still, a very cool finding and another reason why I love my topper.

Further Reading:

The Paper

Map of the Muscles