Physiological Responses and Stroke Variables during Arm Stroke Swimming Using Critical Stroke Rate in Competitive...

Area of Science:

• Sports Science
• Physiology
• Swimming Biomechanics

Background:

• Critical stroke rate (CSR) is a key metric for optimizing swimming performance.
• Understanding physiological responses at different stroke rates is crucial for training prescription.
• Previous research has not fully elucidated the physiological demands across a range of elevated stroke rates.

Purpose of the Study:

• To investigate physiological responses and stroke variables at critical stroke rate (CSR), 105% CSR, and 110% CSR.
• To determine the suitability of CSR for prescribing arm stroke swimming intensity.
• To analyze how different stroke rates affect swimming velocity, heart rate, perceived exertion, and blood lactate.

Main Methods:

• Nine national-level male swimmers determined their CSR through maximal 200m and 400m swims.
• Participants completed three sets of 6x100m swims, with stroke rates set at CSR, 105% CSR, and 110% CSR.
• Physiological data (mean velocity, heart rate, RPE, blood lactate) were collected during the sets.

Main Results:

• Mean swimming velocity, heart rate, and RPE increased significantly with higher stroke rates (CSR to 110% CSR).
• Blood lactate levels were similar at CSR and 105% CSR but significantly higher at 110% CSR.
• Stroke rate remained consistent within sets, and stroke length was maintained from the second to sixth bout at each intensity.

Conclusions:

• Training at CSR and 105% CSR aligns with threshold training intensity.
• Training at 110% CSR corresponds to a high-intensity training level.
• Swimmers can effectively train within the CSR to 110% CSR range without a reduction in stroke length, supporting its use in training prescription.