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Tuesday, June 6, 2023

Effect on Swimming Start Performance of Two Types of Activation Protocols: Lunge and YoYo Squat

Brent Brookbush

Brent Brookbush


Research Review: Effect on Swimming Start Performance of Two Types of Activation Protocols: Lunge and YoYo Squat.

By Sean Butler BS, CSCS, CES, DPT Student

Edited by Brent Brookbush DPT, PT, COMT, MS, PES, CES, CSCS, ACSM H/FS

Original Citation: Cuenca-Fernández, F., López-Contreras, G., & Arellano, R. (2015). Effect on Swimming Start Performance of Two Types of Activation Protocols: Lunge and YoYo Squat. The Journal of Strength & Conditioning Research, 29(3), 647-655. ABSTRACT

Why is this study relevant: Post-activation potentiation (PAP) is a phenomenon in which a muscle’s force is temporarily increased as a result of its contractile history (1). Research suggests that while fatiguing muscle contractions may impair performance, non-fatiguing muscle contractions may enhance performance (2). This 2015 study by Cuenca-Fernández et al. tested the effects of two PAP warm-up protocols, the lunge and YoYo squat , on swim start performance. The results support the use of both protocols to improve swim start performance, with slightly better outcomes using the YoYo squat .

Picture of swimmers on the starting blocks.
Caption: Picture of swimmers on the starting blocks.

Start of the 4x100 meters relay in the Watercube, Beijing, august 11th 2008. Michael Phelps is standing in the number 5 lane

Study Summary

Study DesignQuasi-experimental, repeated measures design
Level of EvidenceIIB Evidence from at least one other type of quasi-experimental study
Participant CharacteristicsDemographics
  • Number of participants: 14 trained swimmers
  • Gender:   4 female, 10 male
  • Height (+/- SD): 176.3 +/- 9.1 cm
  • Weight (+/- SD): 69 +/- 11.4 kg
  • Age: 17 - 23

Inclusion Criteria:

  • Federated swimmers with at least 5 years of experience in national competitions

Exclusion Criteria:

  • N/A
MethodologyPrior to data collection:
  • All swimmers participated in 3 familiarization sessions with the YoYo squat machine
    • In addition, each swimmer’s 3-repetition max was calculated for the lunge exercise

  • Reference points were marked on the swimmers’ hips, knees and ankles for video analysis
  • Participants performed a varied swim warm-up (SWU) of 400m of swimming followed by dynamic stretching of the lower body
  • After an 8-minute rest interval, swimmers performed a 15m time trial that served as a baseline measurement.
    • Competition (FINA) rules were used, and only 1 attempt was allowed to simulate competition conditions.

  • On the day of testing, swimmers were randomly assigned to 1 of 2 groups.
    • Group 1 performed a standardized swim warm-up (SWU) followed by 1 set of 3 of the lunge exercise (LWU) at 85% of the participant’s 1 rep max (1RM).
    • Group 2 performed the SWU followed by 1 set of 4 reps of the YoYo squat exercise (YWU) at maximum voluntary contraction. 4 reps were used because the first rep served to “charge” the flywheel.

  • An 8-minute rest interval followed the PAP stimulus; the duration of the rest interval was based on the results of previous studies (3, 4, 5).
  • Swimmers performed an additional swim start after the rest interval.
  • Following a 1 hour break, Groups 1 and 2 performed the same protocols again but switched PAP protocol (i.e., Group 1 did the YoYo squat, Group 2 did the lunge warm-up)
Data Collection and AnalysisData Collection for Swim Starts:
  • Four digital video cameras recorded each trial.
    • One high-speed camera focused on the block, to analyze takeoff angle and mean angular knee velocity and to calculate block time.
    • The remaining 3 cameras were focused poolside: 1 to record the block phase, 1 to record the underwater phase to 5m, and the last to record the swim phase to 15m.
    • The cameras were synchronized with the starting and timing system.

  • 2 researchers used Kinovea software to independently analyze all video footage.
  • Video analysis included kinematic variables and all measures of time, as described in the Outcome Measures section.

Statistical Analysis

  • After testing for a normal distribution, a repeated measures ANOVA was used to identify differences in swim start performance within and between participants during baseline and PAP conditions.
  • When testing for differences between protocols, significance was set at p<0.05 and the Holm’s Bonferroni method was used to control for Type 1 errors.
  • Intraclass correlation coefficients were used to assess the reliability of the video analysis.
Outcome Measures
  • Dive Distance (meters): Measured from the wall under the swim blocks to the swimmer’s first contact with the water
  • Flight time (seconds): Measured as the time between the last contact of the feet with the starting block and their first contact with the water
  • Mean Horizontal Hip Velocity (meters per second): Horizontal hip distance during flight
  • Time to 5 meters (seconds)
  • Time to 15 meters (seconds)
  • Angle of takeoff (degrees)
  • Angle of entry (degrees)
  • Block time (seconds): Time elapsed between the start strobe flash and the swimmer’s separation from the block
  • Mean angular velocity of knee extension (radian per second): The angular difference in the knees between the moment of maximum flexion (during the “ready” phase before dive) divided by the time elapsed during extension.
  • LWU = Lunge protocol

    YWU = YoYo squat protocol

    SWU = Baseline

  • Dive Distance: The LWU and YWU groups outperformed the SWU group in dive distance:
    • LWU (300.3 +/- 8.7 cm)
    • YWU (304.3 +/- 9.1 cm)
    • SWU (294.2 +/- 8.7 cm)

  • Flight time: Mean flight times were shorter for both the LWU and YWU groups when compared to the SWU group
    • LWU (0.31 +/- 0.14 seconds)
    • YWU (0.28 +/- 0.13 seconds)
    • SWU (0.33 +/- 0.14 seconds)

  • Mean Horizontal Hip Velocity: Participants in the YWU group were fastest overall, followed by those in the LWU and then the SWU groups:
    • LWU (4.15 +/- 0.12 m×s-1)
    • YWU (4.89 +/- 0.12 m×s-1)
    • SWU (3.63 +/- 0.11 m×s-1)

  • Time to 5 meters: YWU group participants were fastest overall, followed by those in the LWU and then the SWU groups:
    • LWU (1.71 +/- 0.05 seconds)
    • YWU (1.65 +/- 0.05 seconds)
    • SWU (1.75 +/- 0.06 seconds)

  • Time to 15 meters: YWU group participants were faster than those in the SWU, but there were no differences between LWU and SWU participants:
    • LWU (7.40 +/- 0.21 seconds)
    • YWU (7.36 +/- 0.22 seconds)
    • SWU (7.54 +/- 0.23 seconds)

  • Angle of takeoff: No differences among the 3 protocols
    • LWU (26.50 +/- 1.8 °)
    • YWU (26.57 +/- 2.16 °)
    • SWU (25.14 +/- 1.61 ° )

  • Angle of entry: No differences among the 3 protocols:
    • LWU (41.92 +/- 1.38 °)
    • YWU (41.21 +/- 1.54 °)
    • SWU (41 +/- 1.19 °)

  • Block time: YWU group participants were faster than those in the SWU and LWU groups:
    • LWU (0.78 +/- 0.03 seconds)
    • YWU (0.74 +/- 0.02 seconds)
    • SWU (0.79 +/- 0.02 seconds)

  • Mean angular velocity of knee extension: Swimmers in the YWU group had the fastest velocity compared to both the  SWU and LWU groups:
    • LWU (89.16 +/- 4.67 rad×s-1)
    • YWU (107.41 +/- 4.89 rad×s-1)
    • SWU (90.99 +/- 4.47 rad×s-1)


Our ConclusionsPost-activation potentiation (PAP) can positively affect swim start performance parameters in national level competitors. This may imply that PAP should be used as part of warm-up protocols (especially prior to competition), as well as during training.
Researchers' Conclusions

Swim start performance is enhanced by both lunge and YoYo squat warm-up protocols. The YoYo squat is recommended before short events as a method to improve start time and angular knee velocity values.

Review & Commentary:

This study adds to a growing body of research on post-activation potentiation (PAP) by measuring the effect of two warm-up protocols on swim start performance parameters. The findings suggest that both lunge and YoYo squat warm-ups enhance the start times of competitive swimmers. Based on these results, human movement professionals may consider recommending PAP as part of a warm-up program before competition in short distance events.

This study had several strengths, including:

  • The repeated measures design allows athletes to act as their own control group. This design helps account for confounding variables such as sleep, nutrition, training experience, genetics, etc.
  • All participants were competitive swimmers, many at the national level. This makes the results generalizable to competitive swimmers.
  • Human movement professionals are familiar with the lunge exercise and commonly have access to the equipment needed to apply this protocol to swim athletes.

Weaknesses that should be noted prior to clinical integration of the findings:

  • The outcome measure of 15m is not associated with an actual event. Future research should use the distance of a specific swim event, such as a 50m freestyle.
  • Use of the YoYo squat machine, an uncommon piece of equipment, makes that warm-up difficult to put into practice. Future research should include a warm-up protocol incorporating body weight and low load split squats , which has been shown to enhance jump performance (6).
  • Although not a weakness of this study, additional exercises with a larger group of participants may provide better practical guidelines for the development of competition warm-ups.

Why This Study is Important:

This research adds to the growing body of evidence on PAP training, establishing lunges and YoYo squat  as effective exercises for increasing swim start performance. Specifically, this study assesses PAP as a warm-up for competitive sport, as opposed to the more commonly assessed attributes of strength (1-3RM) and power (jump height).

How the Findings Apply to Practice:

Human movement professionals should consider using these warm-up protocols when working with swimmers during competition. The YoYo squat resulted in a larger increase in performance, but it is a relatively uncommon piece of equipment that is not easy to transport. The lunge was also effective, and can be easily performed with little or no equipment. Future research should consider investigating body weight and band resisted lunge variations. The lunge has been shown to elicit PAP (6), and body weight or band resistance would make implementation easier prior to competition.

Related to Brookbush Institute Content

The Brookbush Institute (BI) recommends the use of PAP during power training phases of a periodized program, and this research study implies that further consideration should be given to adding PAP into competition warm-up protocols. Based on the findings of this study, the lunge and the YoYo squat provide a PAP stimulus adequate for improving swim starts in competitive swimmers. The Brookbush Institute continues to compile all relevant research and data to optimize warm-up, power training, and PAP protocols.

Below are videos related to the exercises in the study:


Lateral Lunge with Front Rack Resistance

Squat Form and Modifications


  1. Robbins, D. W. (2005). Postactivation potentiation and its practical applicability: a brief review. Journal of Strength and Conditioning Research,19(2), 453.
  2. Lorenz, D. (2011). Postactivation potentiation: An introduction. International Journal of Sports Physical Therapy, 6(3), 234.
  3. Paasuke, M., Ereline, J., & Gapeyeva, H. (2001). Knee extension strength and vertical jumping performance in nordic combined athletes. Journal of Sports Medicine and Physical Fitness, 41(3), 354.
  4. Kilduff, L. P., Cunningham, D. J., Owen, N. J., West, D. J., Bracken, R. M., & Cook, C. J. (2011). Effect of postactivation potentiation on swimming starts in international sprint swimmers. The Journal of Strength & Conditioning Research, 25(9), 2418-2423.
  5. Thompsen, A. G., Kackley, T., Palumbo, M. A., & Faigenbaum, A. D. (2007). Acute effects of different warm-up protocols with and without a weighted vest on jumping performance in athletic women. Journal of strength and conditioning research, 21(1), 52.
  6. Bishop, CJ., Tarrant, J., Jarvis, PT. and Turner, AN (2017). Using the split squat to potentiate bilateral and unilateral jump performance. The Journal of Strength & Conditioning Research, 31(8), 2216-2222.
  7. Bevan, H. R., Cunningham, D. J., Tooley, E. P., Owen, N. J., Cook, C. J. and Kilduff, L. P. (2010). Influence of postactivation potentiation on sprinting performance in professional rugby players. The Journal of Strength & Conditioning Research, 24(3), 701-705.

© 2017 Brent Brookbush

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