The effects of warm-ups protocols aiming to promote post-activation potentiation in Wushu have not been properly analyzed. So, considering the scarce literature on the subject, the purpose of this study was to investigate the acute results of different warm-up protocols on anaerobic functions and lactate plasma levels in female Taolu athletes. Overall, the results of this research showed that there was a significant difference between the four lactate measurements, minimum power and fatigue index. In addition, there was no significant difference between maximum anaerobic power, average anaerobic power and lactate plasma levels with three warm up protocols. All protocols seem to be equally effective and could therefore be used interchangeably, at least in terms of the variables that were analyzed in this study. It is possible that neuromuscular responses could have been more specific to the type of warm-up used.
As our findings present all three WU protocols, WushuWU, StreWU, and SpeWU, showed a significant increase in blood lactate in comparison to before the warm-up, with a subsequent decrease after a 5-minute rest and after performing RAST (again, too assess the effects of PAP and not PAPE). Specific warm-up is a common activity in Taolu, including a collection of traditional movements consisting of light aerobic activity, with static and dynamic stretching used before competitions [33]. The specific warm-up places an emphasis on getting the body ready for the physiological demands of the Taolu. In other words, the lactate concentration previously has been reported to be 10.2±1.5 mmol/L after performing Taolu form [1]. We therefore designed different warm up protocols based on some activities that performed to make a pressure on anaerobic energy system that is a main energy source involved in Taolu. We found that blood lactate was increased after warm up (10.8-12.4 mmol/L) and RAST (15.5-16.3 mmol/L) almost at the same level of the blood lactate concentration during performing Taolu form [1] and that values reported by Goodwin et al. [34]. One of the standards of reaching VO2max is a lactate concentration of 8-12 mmol/L [35], meaning that RAST did promote maximal exertion. In a research done on cyclists, the validity of the RAST with the Wingate test was compared. The lactate concentrations in the RAST were 7.7±1.9 and 8.0±1.9 and 6.2±1.6 mmol/L at the rest times 4, 8 and 12 minutes after the test, respectively [36]. Overall, the results of present study show that subjects performed RAST with highest attempts and we also can figure out that performing RAST test can be a suitable pattern for Wushu athletes at Taolu style. It also can be assumed that all three warm-up methods (special for Wushu athletes and PAP methods) had a similar impact on lactate concentration, and it is possible that the pressure on athletes is the same. In this regard, our data about blood lactate after RAST and the blood lactate values reported previously [1, 34] could be conformation why we used RAST to monitor variables involved in Taolu form. As we mentioned Taolu performance take place about 80 seconds with involving mainly glycolytic system with performing high intensity and short duration[2], RAST was a suitable activity pattern to put the same exertion and intensity on variables involved in Taolu form.
Among the factors considered to be efficient for warm up activities like PAP and its efficiency, training status and type of individual activity are other factors that can play an important role in warm up process. It is possible that participants have benefited from the intervention, while others have seen their performance impaired. It has been suggested that the most desirable response of PAP has been demonstrated in trained people and competitive athletes [19], although contradictory findings have been reported [37]. In our study, data is supporting the latter: The Wushu athletes under investigation had enough experience and all of them were the Iran and Kermanshah athletes, and Wushu itself is a sport requiring a combination of speed, power and force. This points to PAP being a very complex phenomenon, where a proper balance between potentiation and fatigue have to be achieved, and this balance might be highly individualized [38].
Our findings showed that the minimum power and fatigue index were significantly different. Some researchers reported same result as the present investigation [5, 20, 24], but the study of RAST and on athletes with physiological feature similar to Wushu athletes, was not found. Still, Till et al. investigated the PAP effect on sprint and jump performance of male academy soccer players and showed that these functions did not have any significant change [5]. Another study [24] examined the total change of jump and maximum jump, peak power, vertical peak force, rate of force development and relative force, and observed that there was no significant difference in variables, but the displacement rate in PAP group was more than non-PAP groups. Also, an investigation explored if changes in muscle architecture affected PAP [20], and the results showed that protocols did not create any significant difference in the performance of the vertical jump, but protocols with moderate and high intensity made some intensive changes in muscle architecture. Performing PAP programs, involved energy producer systems and athletes’ experiences can be the main factors of existed differences. The significant difference was reported on the group that performed the strength protocol. For example, StreWU, including 2 sets and 4 repeats of Squat with 70 % 1RM, had a significant impact on minimum power comparing to WushuWU (3.42 vs. 2.9 w/kg/m) that means StreWu probably prevent force output reduction during RAST protocol and maintain the difference between peak power and minimum power with lowest variation. This could provide athlete in situation to perform RAST with high stability and show lower fatigue index.
On the contrary, several studies reported the increase of power function or speed after PAP [39–43]. For example, Linder et al. [41] investigated the effects of preload 4 repetition maximum on 100m sprint times in collegiate women. The results showed that the PAP group had 0.19 seconds improvement in the 100 m track sprint. A different research reported in improvement in performance of swimmers in 100 m freestyle swimming, by investigating the effect of PAP on the speed swimming performance. A significant improvement in 100-m freestyle swim time (0.54 seconds) has been reported for the PAP trial vs. the control trial [21]. The PAP response was also investigated on recreational trained athletes and showed that PAP is a suitable and durable method for increasing the explosive force performance of athletes [44]. Other authors evaluated the acute effects of PAP in Special Judo Fitness Tests (SJFT), and showed that contrast exercise (maximum force combined with plyometric exercises) before SJFT lead to an increase in power and speed of Judo performers more than plyometric or maximum force interventions separated [23]. Furthermore, a study concluded that the use of 1 to 3 sets of half squats performed at moderate to high training loads (1RM, 3RM, 5RM and 60% 1RM) may be a very effective strategy to meaningfully improve explosive performance of Counter Movement Jump (CMJ) in highly trained subjects [45]. Perhaps our study is suggesting that RAST may not be the most sensitive test to denote PAP, while vertical jumping tests may deliver better information. Another relevant issue concerns the balance between PAP and fatigue. It is also possible that our warm-up protocols have produced too much fatigue, impairing any benefits from PAP, because the mechanisms involving fatigue would likely surpass any benefits from PAP protocols. Alternatively, maybe such a prolonged warm-up (especially considering the nature of the competitive distance) brings such fatigue levels that the addition of PAP protocols in that timing are inducing more additional fatigue than an effective potentiation [16]. With a longer recovery time after PAP followed by a more prolonged and/or intense PAP workout, perhaps the desired potentiation effect would have been achieved. However, such potentiation could perhaps rely more on mechanisms behind PAPE, instead of the mechanisms involded in PAP.
Importantly, a difference in individual force (such as was observed in back squat 1RM) might influence the time of potentiation of subjects; after revocation stronger person needs less rest (5-10 min), while weaker person needs more durable rest (15-20 min) [22]. Even when performing a given set of repetitions with a pre-stipulated range of repetitions, these might widely diverge for the same percentage of 1-RM [46]. The variety of responses in people showed that in order for developing the performances, PAP should be considered individually [38, 45] and with regard to factors like method, volume, load, recovery and other individual differences.
In summary, all three warm-up protocols showed similar effects on blood lactate concentration from rest to after warm-up, before and after the RAST. Also, with the exception of the minimum power and FI, other factors like peak power and mean power showed the same results in all three WU protocols. A lower value of FI may indicate a greater ability to maintain anaerobic performance that was obsvered in StreWU protocol. And, a higher FI value may show higher perssure on Taulo athletes during warm up resulting to insufficient recovery after warm up.
PRACTICAL APPLICATIONS
The results show that a suitable warm-up before a competition can increase the functionality by influencing different physiological parameters, but different strength and speed based-PAP warm up protocols in this study did not create a significant change in most of variables. Considerng these findings, it is noted that the spicific sports such as Taolu form has not been affected by PAP WU protocols althought strengthed-based PAP protocols probably increase improvements in power-related performance in Taolu form. In additin, overly prolonged and/or intense warm-ups may generate more fatigue than potentiation, perhaps defeating the main purpose of this part of the training session. Finally, each athlete may perform the type of warm-up that enjoys the most, since similar effects will be produced and greater motivation may ensue. Future studies should expand on the inter-individual variability in response to different warm-up protocols, as well as analyze the individual motivations for performing each specific type of warm-up.