Acute Effects of Two Different Warm-Up Protocols on Flexibility and Lower Limb Explosive Performance in Male and Female High Level Athletes

摘要

This study examined the effects of two different warm-up protocols on lower limb power and flexibility in high level athletes. Twenty international level fencers (10 males and 10 females) performed two warm-up protocols that included 5-min light jogging and either short (15s) or long (45s) static stretching exercises for each of the main leg muscle groups (quadriceps, hamstrings and triceps surae), followed by either 3 sets of 3 (short stretching treatment), or 3 sets of 5 tuck jumps (long stretching treatment), in a randomized crossover design with one week between treatments. Hip joint flexion was measured with a Lafayette goniometer before and after the 5-min warm-up, after stretching and 8 min after the tuck jumps, while counter movement jump (CMJ) performance was evaluated by an Ergojump contact platform, before and after the stretching treatment, as well as immediately after and 8 minutes after the tuck jumps. Three way ANOVA (condition, time, gender) revealed significant time (p < 0.001) and gender (p < 0.001) main effects for hip joint flexion, with no interaction between factors. Flexibility increased by 6. 8 ± 1.1% (p < 0.01) after warm-up and by another 5.8 ± 1.6% (p < 0.01) after stretching, while it remained increased 8 min after the tuck jumps. Women had greater ROM compared with men at all time points (125 ± 8° vs. 94 ± 4° p<0.01 at baseline), but the pattern of change in hip flexibility was not different between genders. CMJ performance was greater in men compared with women at all time points (38.2 ± 1.9 cm vs. 29.8 ± 1.2 cm p < 0.01 at baseline), but the percentage of change CMJ performance was not different between genders. CMJ performance remained unchanged throughout the short stretching protocol, while it decreased by 5.5 ± 0.9% (p < 0.01) after stretching in the long stretching protocol However, 8 min after the tuck jumps, CMJ performance was not different from the baseline value (p = 0.075). In conclusion, lower limb power may be decreased after long periods of stretching, but performance of explosive exercises may reverse this phenomenon.Key points class="unordered" style="list-style-type:disc">Stretching of the main leg muscle groups for 45 s results in a relatively large decrease (by 5.5%) in subsequent jumping performanceStretching of the main leg muscle groups for only 15 s results in an increase in flexibility similar to that of the longer duration stretching (by 12.6%), with no change in subsequent jumping performancePerformance of a PAP exercise such as tuck jumps may reverse the negative effects of long duration stretching on leg muscle power. However, jumping performance is not increased above baselineSpeed/power athletes should be advised against using long duration stretching. The number of repetitions of a PAP exercise such as the tuck jumps, should be further examined in order to induce an increase in explosive performance during competition class="kwd-title">Key words: Countermovement jump, stretching, post-activation potentiation, fencing class="head no_bottom_margin" id="sec1-1title">IntroductionAthletes competing in speed/power sports are often required to have both high leg muscle power and flexibility in order to perform explosive and wide movements and avoid injuries during training and competition (Baechle et al., ; Behm and Chaouachi, ). Prior to training and competition, athletes perform a warm-up routine, aiming to prepare their muscles to attain maximal power and coordination as well as to increase joint range of motion. These are attained by increasing muscle temperature, usually through light exercise, and by performing kinetic patterns that mimic movements of the sport (Baechle et al., ; Shellock and Prentice, ). A typical warm-up contains both stretching exercises and maximal or near maximal muscle actions, so that ample and explosive movements can be performed in the training or competition that follows (Young and Behm, ). However, several studies have shown that static stretching exercises that are commonly used by athletes prior to training or competition may impair muscle power, sprint speed, agility and balance (Bacuraeu et al., ; Mac Millian et al., ; Winchester et al., ). The duration of static stretching seems to play a critical role in these performance impairments (Behm and Chaouachi, ).On the other hand the dynamic general or specific explosive movements that are typically performed during warm-up may induce a phenomenon called post-activation potentiation (PAP) that enhances muscle power in the following 3-20 minutes (Gelen, ; Hilficker et al., ; Hodgson et al., ; Kilduff et al., ). Although the effects of stretching and dynamic muscle actions on consequent explosive movements are opposing (decrease and increase muscle power, respectively), most previous studies have examined their effects separately. For example, Thompsen et al., reported lower vertical and long jump performance following static stretching, compared with another condition where dynamic exercises with or without an external load (vest) were used. Furthermore, Gellen, () and Vetter, , demonstrated the negative effects of static stretching on jumping, sprint, and specific soccer drills performed after general warm-up, while Chaouachi et al. (href="#ref10" rid="ref10" class=" bibr popnode tag_hotlink tag_tooltip" id="__tag_331379215">2010) in their study conducted in highly trained sprinters, asserted that static stretching exercises to point of discomfort applied 5 min after a general warm-up did not adversely affect sprinting and jumping performance. Interestingly, dynamic stretching can reduce or even reverse the detrimental effects of static stretching (Gelen, href="#ref16" rid="ref16" class=" bibr popnode tag_hotlink tag_tooltip" id="__tag_331379227">2010; Behm and Chaouachi, href="#ref6" rid="ref6" class=" bibr popnode tag_hotlink tag_tooltip" id="__tag_331379196">2011; Turki et al., href="#ref41" rid="ref41" class=" bibr popnode tag_hotlink tag_tooltip" id="__tag_373098786">2011).Only a few studies have examined the acute effects of different warm-up methods on power and sport-specific performance. For example, Tsolakis et al., href="#ref38" rid="ref38" class=" bibr popnode">2010a did not find any significant differences on flexibility, jumping ability and leg functional characteristics of fencing performance after either static or ballistic stretching of the lower limbs in international level fencers, suggesting that both types of stretching can be used during pre-competition warm-up of a speed/power sport However, there is a lack of studies examining the effects of a realistic pre-competition warm-up, containing both stretching and potentiating exercises, on flexibility and muscle power.Therefore, the aim of this study was to examine the combined effect of stretching and muscle potentiating exercises that are used in a speed/power sport warm-up, on leg muscle power and flexibility. More specifically, the effect of two different stretching durations (long and short) was studied in combination with pre-conditioning tuck jumps, used to enhance muscle power. It was hypothesized that the longer static stretching protocol would adversely affect power performance (Behm and Chaouachi, href="#ref6" rid="ref6" class=" bibr popnode tag_hotlink tag_tooltip" id="__tag_331379204">2011href="#ref10" rid="ref10" class=" bibr popnode tag_hotlink tag_tooltip" id="__tag_331379218">), but the plyometric exercises (tuck jumps) would counteract the detrimental effects of static stretching (Tillin and Bishop, href="#ref36" rid="ref36" class=" bibr popnode tag_hotlink tag_tooltip" id="__tag_331379225">2009).