Do Thirty-Second Post-activation Potentiation Exercises Improve the 50-m Freestyle Sprint Performance in Adolescent Swimmers?

Swimming Warm-Up and Beyond: Dryland Protocols and Their Related Mechanisms—A Scoping Review

In swimming, the beneficial effects of the in-water warm-up are often undermined by the long transition periods before competition (≥ 20 min). For that reason, studies comparing the effects of in-water warm-ups followed by dryland activities have been conducted in the swimming literature. This has brought conflicting evidence due to large combinations of supervised and unsupervised warm-up procedures used. Therefore, a scoping review was performed to discuss (1) why warm-up strategies are important for competitive swimming; to identify (2) what are the different warm-up approaches available in the literature, and; to establish (3) what are the main conclusions, considerations and gaps that should be addressed in further research to provide clearer guidance for interventions. The search was conducted on PubMed, Web of Science, Scopus, and SPORTDiscus databases. To be considered eligible, studies must have assessed acute short-term responses of warm-up procedures in swimmers by using randomized controlled trials or pre-post study designs. A total of 42 articles were included in this review. The effectiveness of warm-up responses was evaluated based on the inclusion or not of warm-up, the type of conditioning activity (in-water exercise, in-water exercise combined with dryland or dryland exercise only), its duration, and intensity. (1) Warm-up mechanisms have been mainly related to temperature changes associated to cardiovascular adaptations and short-term specific neuromuscular adaptations. Thus, maintaining muscle activity and body temperature during the transition phase immediately prior to competition could help swimmers' performance; (2) the most common approach before a race usually included a moderate mileage of in-water warm-up (~ 1000 m) performed at an intensity of ≤ 60% of the maximal oxygen consumption, followed by dryland protocols to keep the muscle activity and body temperature raised during the transition phase. Dryland activities could only optimize performance in sprint swimming if performed after the in-water warm-up, especially if heated clothing elements are worn. Using tethered swimming and hand-paddles during warm-ups does not provide superior muscular responses to those achieved by traditional in-water warm-ups, possibly because of acute alterations in swimming technique. In contrast, semi-tethered resisted swimming may be considered as an appropriate stimulus to generate post-activation performance enhancements; (3) nothing has yet been investigated in backstroke, butterfly or individual medley, and there is a paucity of research on the effects of experimental warm-ups over distances greater than 100 m. Women are very under-represented in warm-up research, which prevents conclusions about possible sex-regulated effects on specific responses to the warm-up procedures.

Understanding the Role of Propulsion in the Prediction of Front-Crawl Swimming Velocity and in the Relationship Between Stroke Frequency and Stroke Length

Introduction: This study aimed to: 1) determine swimming velocity based on a set of anthropometric, kinematic, and kinetic variables, and; 2) understand the stroke frequency (SF)–stroke length (SL) combinations associated with swimming velocity and propulsion in young sprint swimmers.

Methods: 38 swimmers (22 males: 15.92 ± 0.75 years; 16 females: 14.99 ± 1.06 years) participated and underwent anthropometric, kinematic, and kinetic variables assessment. Exploratory associations between SL and SF on swimming velocity were explored using two two-way ANOVA (independent for males and females). Swimming velocity was determined using multilevel modeling.

Results: The prediction of swimming velocity revealed a significant sex effect. Height, underwater stroke time, and mean propulsion of the dominant limb were predictors of swimming velocity. For both sexes, swimming velocity suggested that SL presented a significant variation (males: F = 8.20, p < 0.001, η² = 0.40; females: F = 18.23, p < 0.001, η² = 0.39), as well as SF (males: F = 38.20, p < 0.001, η² = 0.47; females: F = 83.04, p < 0.001, η² = 0.51). The interaction between SL and SF was significant for females (F = 8.00, p = 0.001, η² = 0.05), but not for males (F = 1.60, p = 0.172, η² = 0.04). The optimal SF–SL combination suggested a SF of 0.80 Hz and a SL of 2.20 m (swimming velocity: 1.75 m s⁻¹), and a SF of 0.80 Hz and a SL of 1.90 m (swimming velocity: 1.56 m s⁻¹) for males and females, respectively. The propulsion in both sexes showed the same trend in SL, but not in SF (i.e., non-significant variation). Also, a non-significant interaction between SL and SF was observed (males: F = 0.77, p = 0.601, η² = 0.05; females: F = 1.48, p = 0.242, η² = 0.05).

Conclusion: Swimming velocity was predicted by an interaction of anthropometrics, kinematics, and kinetics. Faster velocities in young sprinters of both sexes were achieved by an optimal combination of SF–SL. The same trend was shown by the propulsion data. The highest propulsion was not necessarily associated with higher velocity achievement.

Effects of Postactivation Performance Enhancement on the Vertical Jump in High-Level Volleyball Athletes

The objective of this study was to evaluate the effects of a training session with and without an intervention of postactivation performance enhancement (PAPE) on countermovement jump (CMJ) height, perceived recovery status (PRS), and ratings of perceived exertion (RPEs), followed by a specific volleyball training session. The sample consisted of sixteen professional male volleyball players, with an average age of 26.8±6.1 years and average height of 195.9±6.7 cm, randomly divided into a group with PAPE intervention (GPAPE) (n=8), and a control group (CTRL) without PAPE intervention (n=8). The control group carried out the training session with plyometric exercises, and the GPAPE added conditioning protocols for PAPE to plyometric training, followed by a technical tactical volleyball session. At the end of the training session, there was an increase of 16.3% in the height of the CMJ in the GPAPE, while the CTRL showed a decrease of 5% in the height of the CMJ. PRS and RPE variables did not differ between the groups. It was concluded that PAPE had a positive effect on the height of the vertical jump after plyometric training, which was maintained until the end of the technical and tactical volleyball session.

Upper-Body Post-activation Performance Enhancement for Athletic Performance: A Systematic Review with Meta-analysis and Recommendations for Future Research

BACKGROUND

Research on post-activation performance enhancement (PAPE) is dominated by lower-body conditioning activities/performance test complexes. Despite the contribution of the upper body to many sporting actions, no review on upper-body PAPE currently exists.

OBJECTIVES

The aim of this systematic review with meta-analysis was to provide a synthesis of the available research on the inclusion of upper-body PAPE conditioning activities to improve athletic performance.

METHODS

A review of the literature was conducted according to the Preferred Reporting Items for Systematic Review and Meta-analyses guidelines, including a literature search of EBSCOhost, SPORTDiscus, PubMed and Google Scholar databases. A total of 127 studies were identified through database searches, and were assessed against the following criteria: (1) randomised controlled trial or pre-and-post study design; (2) studies explored the effects of prior voluntary muscle activity, and not electrically induced contractions, (3) evidence, or lack thereof, of PAPE was quantified by the monitoring of individual performance to commonly applied physical tests or sport-specific tasks; (4) conditioning activities and performance tests were primarily upper-body; (5) detailed description of a standardised warm-up; and (6) full-text versions of studies could be accessed in English language peer-reviewed journals. Studies were quality assessed for methodological quality via the PEDro scale and ranked accordingly.

RESULTS

Thirty-one studies met the inclusion criteria. Studies were classified into different conditioning activity modes: bench press variations, sport-specific (modified implement throws, swing-specific, cable pulley, elastic resistance, combination) and bodyweight activity. Acute performance enhancement in several movement-specific combinations was found. A meta-analysis revealed that bench press at  ≥ 80% one repetition maximum significantly (p = 0.03; ES = 0.31) improves subsequent power output in the ballistic bench throw at 30-40% one repetition maximum, following 8-12 min recovery. Additionally, sport-specific overweight implement throws improved subsequent throwing distance at competition weight by ~ 1.7-8.5%; ES = 0.14-0.33, following 3 min recovery. Sport-specific lighter weighted bat swings and swing-specific isometrics resulted in improved subsequent competition weight bat swing velocities, ranging from ~ 1.3-4.9%; ES = 0.16-0.57.

CONCLUSIONS

This review presents several upper-body movement-specific conditioning activities that could be considered by coaches and practitioners as part of complex or contrast training, or used in pre-competition warm-ups to acutely enhance performance.

Young Swimmers' Anthropometrics, Biomechanics, Energetics, and Efficiency as Underlying Performance Factors: A Systematic Narrative Review

Introduction: In youth swimming, researchers are interested in understanding how anthropometry and parameters related to swimming technique (biomechanics, energetics, and efficiency) influence the performance. However, there is not any review in the literature that consolidates the body of knowledge of this topic. The objective of this study was to review systematically the current body of work on the influence of determinant factors related to swimming technique (biomechanics, energetics, and efficiency) and anthropometry in the young performance of swimmers.

Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to identify relevant studies.

Results: After screening, 240 studies were analyzed and 59 related to swimming performance, and its determinant factors were retained for synthesis. Studies revealed a high-quality index by PEDro scale (mean score was 7.17 ± 1.40). Twenty-five studies were longitudinal designs and the remaining 34 cross-sectional designs. Most of the studies (N = 39, 66.1%) reported concurrently two or more determinant factors (anthropometrics, biomechanics, energetics, and efficiency).

Conclusion: Youth swimming research relies on a multifactorial assessment. From the synthesis, it is possible to conclude that the performance of young swimmers is characterized by a multifactorial, holistic, and dynamic phenomenon. Better performance has always been related to better swimming technique and higher anthropometrics. This suggests that both anthropometrics (i.e., nature) and training (i.e., nurture) play key roles in the swimming performance of young swimmers.

Proposal of a Conditioning Activity Model on Sprint Swimming Performance

This study aimed to propose a conditioning activity (CA) model to stimulate improvement on neuromuscular responses, mechanical parameters and for the 50-m freestyle swimming. Thirteen male swimmers (19 ± 3 years and performances of 77% in relation to World Championship records) performed four CA protocols followed by a maximum performance in the 50-m freestyle. In the first protocol (P1) swimmers performed a standard warm-up (∼15 min); in the second protocol (P2) lunges (3 × 85% of the one-repetition maximum); in the third (P3) pull-ups (3 maximum repetitions) and box jumps 40 cm high and 60 cm deep (1 × 5 with 10% of the corporal weight); and in the fourth protocol (P4) a combination of exercises from the second and third protocols. CA protocols had no effect on the standard warm-up. However, P2 performance (27.01 ± 1.25 s) was similar to P1 (27.01 ± 1.18 s) and presented higher positive effects in mechanical parameters for the swim start performance in comparison to other protocols, contributing to improvements in the 50-m freestyle. In addition, turnaround time also had a negative effect, mainly in P3 (3.12 ± 0.28 s), signaling the improvement of this variable in all protocols (P1: 3.30 ± 0.38 s; P2: 3.17 ± 0.30 s; P4: 3.17 ± 0.34 s). P2 (after: 80 ± 11%; before: 82.7 ± 9.9%) and P3 (after: 82.7 ± 9.9%; before: 85.1 ± 9.7%) presented a possible positive effect on the percentage of voluntary activation in relation to P1 (after: 79.3 ± 10.7%; before: 76.3 ± 12%). In conclusion, the proposed conditioning activity protocols were not efficient for performance improvement in the 50-m freestyle compared to the standard model and seem to specifically influence each phase of the event.

Postactivation potentiation effects of Back Squat and Barbell Hip Thrust exercise on vertical jump and sprinting performance

BACKGROUND

This study aimed to determine and compare the post-activation potentiation (PAP) effects of the Back Squat (SQ-PAP) and Hip Thrust (HT-PAP) exercises in terms of vertical jump height (VJ), 20-yard dash and 40-yard dash time in physically active university students. Considering the Force-vector theory, it was hypothesized that HT-PAP would induce greater potentiation for 40-yard dash than SQ-PAP whereas SQ-PAP would induce greater potentiation for 20-yard dash and VJ than HT-PAP.

METHODS

Seventeen kinesiology and exercise science students (8 male and 9 female) who resistance train at least 3 times/week (age, 21.71±1.49 years; body mass, 75.58±11.89 kg; height, 173.98±11.88 cm and training experience 5.47±2.00 years) joined this study. They performed three experimental sessions namely; baseline (BL), SQ-PAP loading session and HT-PAP loading session with 48 hours interval with a randomized open crossover study design. BL session was also accepted as control and familiarization session. SQ-PAP and HT-PAP exercises were performed roughly at 90% of 1 Repetition maximum (1 RM) of the subjects with three repetitions. Subjects were tested for vertical jump height (VJ), 20-yard dash and 40-yard dash time before and 8 minutes after each PAP loading exercise.

RESULTS

Statistical analysis revealed that the potentiation effects of SQ-PAP and HT-PAP exercises on VJ height, 20-yard and 40-yard dash were similar that none of the loading exercises with 8 min rest interval had any increasing or detrimental performance effect on VJ (P=0.923), 20-yard dash (P=0.133) as well 40-yard dash time (P=0.570).

CONCLUSIONS

These findings demonstrate that none of the loading protocols with above mentioned exercises have any detrimental or improving effects on VJ height, 20-yard dash and 40-yard dash time for physically active university students who joined this study. Although no acute potentiation effect has been found, this study also shows that SQ-PAP, HT-PAP exercises can be used interchangeably and safely to avoid training monotony during longer training periods for chronic adaptations.

Effects on performance of active and passive hypoxia as a re-warm-up routine before a 100-metre swimming time trial: a randomized crossover study

Passive and active hypoxia could be used as a tool during a transitional phase to maintain the effects of warm-up and optimize athletic performance. Our purpose was to evaluate and compare the effects of four different re-warm-up strategies, i.e. rest in normoxia (RN) at FiO₂ = 20.9%, rest in hypoxia (RH) at FiO₂ = 15%, active (5 minutes dryland-based exercise circuit) in normoxia (AN) and active in hypoxia (AH), during the transitional phase, on subsequent 100 m maximal swimming performance. Thirteen competitive swimmers (n = 7 males; n = 6 females; age: 15.1±2.1 years; height: 164.7±8.8 cm; weight: 58.1±9.7 kg; 100 m season’s best time 72.0±11.8 s) completed a 20-minute standardized in-water warm-up followed by a 30-minute randomized transitional phase and 100 m freestyle time trial. Compared to AH (73.4±6.2 s), 100 m swim time trials were significantly (p = 0.002; η² = 0.766) slower in RN (75.7±6.7 s; p = 0.01), AN (75.2±6.7 s; p = 0.038) and RH (75.0±6.4 s; p = 0.009). Moreover, compared to AH (36.3±0.4ºC), tympanic temperature was significantly lower (p<0.001; η² = 0.828) at the end of the transitional phase in passive conditions (RN: 35.9±0.6; p = 0.032; RH: 36.0±0.4; p = 0.05). In addition, countermovement jump height at the end of the transitional phase was significantly higher in active than in passive conditions (p = 0.001; ^η2 = 0.728). A dryland-based circuit under hypoxia could be useful to swimmers, once it has attenuated the decline in tympanic temperature during a 30-minute transitional phase after warm-up, improving 100 m swimming performance in young amateur swimmers.

Effect of Tethered Swimming as Postactivation Potentiation on Swimming Performance and Technical, Hemophysiological, and Psychophysiological Variables in Adolescent Swimmers

OBJECTIVES

To investigate whether tethered swimming (TS) performed 8 minutes before a 50-m freestyle swimming sprint could be an effective postactivation potentiation method to improve performance in young swimmers.

METHODS

Fourteen regional-level male adolescent swimmers (age 13.0 [2.0] y; height 161.1 [12.4] cm; body mass 52.5 [9.5] kg) underwent 2 trial conditions in a randomized and counterbalanced order (1 experimental [TS], 1 control) on different days. During the experimental session, the participants performed a standard warm-up of 1200 m followed by a TS exercise, which consisted of 3 × 10-second maximal efforts of TS with 1-minute rests between bouts. In the control condition, the warm-up phase was immediately followed by 200 m at a moderate pace (same duration as the TS in the experimental session). Performance (time trial); biomechanical (stroke length), physiological (blood lactate concentrations), and psychophysiological (ratings of perceived exertion) variables; and countermovement-jump (CMJ) flight time were collected.

RESULTS

TS warm-up had no significant effect on 50-m swimming performance (P = .27), postexercise ratings of perceived exertion, stroke length, or CMJ flight time (P ≥ .05). Blood lactate concentrations significantly increased at the end of the warm-up in the TS condition only (interaction effect: F1.91,29.91 = 4.91, P = .01, η2 = .27) and after the 50-m trial in both conditions (F1.57,20.41 = 62.39, P = .001, η2 = .82).

CONCLUSIONS

The present study demonstrated that 3 × 10-second TS exercises performed 8 minutes prior to the event did not affect ratings of perceived exertion, stroke length, or CMJ flight time. In addition, tethered swimming did not affect 50-m freestyle sprint performance in young swimmers.

Impact of Active and Passive Hypoxia as Re-Warm-Up Activities on Rugby Players' Performance

The aim of this study was to analyse the effect of four types of re-warm-up (R-WU) activity, namely rest in normoxia (RN) at FiO2 = 20.9%, rest in hypoxia (RH) at FiO2 = 15%, activity (4 × 5 jumps/15 s) in normoxia (AN) and activity in hypoxia (AH) on physical performance. Ten elite male rugby players completed a 15-min warm-up followed by one of the 15-min randomized R-WU strategies. After R-WU, countermovement jump (CMJ), 20 m sprint and repeat sprint ability (RSA) tests were assessed. Compared to passive strategies (RN and RH), tympanic temperature was higher after active R-WU (AN and AH) (p = 0.016). Higher values of CMJ height (p = 0.037) and 20 m sprint (p = 0.02) were found in AH than in RN. In addition, mean RSA was lower (p = 0.008) in AH than in RN and RH. Blood lactate concentration was higher (p = 0.007) after RN and AN strategies than after AH. Muscle O2 saturation (p = 0.021) and total Hb (p = 0.042) were higher after AH than after the other three conditions and after RN, respectively. Therefore, an active R-WU under hypoxia could be useful to elite rugby players, once it had attenuated the decline in tympanic temperature during a 15-min period after warm-up, improving jump, sprint and RSA performance.

Influence of Slow-Paced Breathing on Inhibition After Physical Exertion

This research aims to investigate whether slow-paced breathing (SPB) improves adaptation to psychological stress, and specifically inhibition, when it is performed before or after physical exertion (PE). According to the resonance model, SPB is expected to increase cardiac vagal activity (CVA). Further, according to the neurovisceral integration model, CVA is positively linked to executive cognitive performance, and would thus play a role in the adaptation to psychological stress. We hypothesized that SPB, in comparison to a control condition, will induce a better adaptation to psychological stress, measured via better inhibitory performance. Two within-subject experiments were conducted with athletes: in the first experiment (N = 60) SPB (or control – neutral TV documentary) was realized before PE (“relax before PE”), and in the second experiment (N = 60) SPB (or the watching TV control) was realized after PE (“relax after PE”). PE consisted of 5 min Burpees, a physical exercise involving the whole body. In both experiments the adaptation to psychological stress was investigated with a Stroop task, a measure of inhibition, which followed PE. Perceived stress increased during PE (partial η² = 0.63) and during the Stroop task (partial η² = 0.08), and decreased during relaxation (partial η² = 0.15), however, no effect of condition was found. At the physiological level PE significantly increased HR, RF, and decreased CVA [operationalized in this research via the root mean square of successive differences (RMSSD)] in both experiments. Further, the number of errors in the incongruent category (Stroop interference accuracy) was found to be lower in the SPB condition in comparison to the control condition, however, these results were not mediated by RMSSD. Additionally, the Stroop interference [reaction times (RTs)] was found to be lower overall in “relax before PE,” however, no effect was found regarding SPB and Stroop interference (RTs). Overall, our results suggest that SPB realized before or after PE has a positive effect regarding adaptation to psychological stress and specifically inhibition, however, the underlying mechanisms require further investigation.