Effects of ibuprofen during 42-km trail running on oxidative stress, muscle fatigue, muscle damage and performance: a randomized controlled trial

ABSTRACT

Up to 75% of marathon runners ingest non-steroidal anti-inflammatory drugs (NSAIDs) during competition. Despite the doubt whether or not they contribute to performance, the effect of NSAID in endurance sports is unclear. We evaluated the effect of ibuprofen (IBU) use on oxidative stress, muscle damage, physical performance, and vertical jump of runners participating in a 42-km-trail running. The sample consisted of 12 men randomly divided into 2 groups: a placebo group (placebo) and an ibuprofen group (IBG). A 400-mg IBU capsule was administered to the IBG 15 min prior to the start of the trial and during the course after 5 h. In the intergroup analysis, placebo 70.1% increase (p < 0.0001; Cohen’s d = 4.77) of the thiobarbituric acid reactive substances (TBARS); the IBG exhibited a 31.46% increase of the sulphhydryl groups (SH) (p = 0.024, Cohen’s d = 0.27), 55% of squat jump (SJ) (p < 0.01; Cohen’s d = 1.41) with no significant effect on creatine kinase (CK), pace, speed, and finish time. In summary, IBU had positive evidence on oxidative stress and muscle fatigue, but had no effect on physical performance and muscle damage.

KEYWORDS:

• Ibuprofen
• oxidative stress
• muscle damage
• performance
• trail running

Introduction

Trail running (TR) is performed in hilly and mountainous environments and is characterized by a high technical complexity of terrains and paths (Gajardo-Burgos et al., 2021). During the course, extensive muscular activity and relevant overload in the eccentric contraction phase occurs due to natural slopes and obstacles (de Souza et al., 2020). These stimuli result in the hypercatabolism of muscle structures, such as cytoskeleton, sarcomeres, and T-tubes (Fridén & Lieber, 2001); increased levels of inflammatory biomarkers (Comassi et al., 2015); muscle damage (Jastrzȩbski et al., 2015); incidence of lesions (Newsham-West et al., 2010); and high stress related to oxidative signalling (Nieman et al., 2003). Oxidative stress (OS) is associated with long-term, strenuous, and high-intensity exercises, which increases oxygen uptake and the production of reactive oxygen species (ROS) (Mrakic-Sposta et al., 2015); and thus, ultramarathoners are potentially vulnerable to oxidative diseases (Mrakic-Sposta et al., 2015). It is important to maintain the balance of ROS production, since high concentrations often lead to pro-oxidant intracellular homoeostatic disorders and deleterious reactions with significant molecules, such as lipids, carbohydrates, proteins, and DNA (Weydert & Cullen, 2010).

The elevation of OS and the inflammatory response during long-term exercises are closely related to increased pain (Ndengele et al., 2008) and muscle fatigue (Goulart et al., 2020, Theofilidis et al., 2018). The lower limbs receive a great load of activity during the running and there are many reports of muscle pain (Rowlands et al., 2012) and influence the increase in the withdrawal rate of competitions (Millet, 2011). Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (IBU), are commonly believed to reduce pain and muscle damage among trail runners in an attempt to increase their running performance (de Souza et al., 2020).

IBU is a compound belonging to the group of derivatives of propionic acid, one of the NSAIDs popularly consumed and easily acquired in pharmacies (McGettigan & Henry, 2013, Torjesen, 2020) with 35–75% of ultramarathon runners found to ingest NSAID during competition (Hoffman & Fogard, 2011, Lipman et al., 2017). Its use promotes antipyretic, analgesic, and anti-inflammatory effects (Lima et al., 2016). However, the use of NSAIDs during strenuous exercise is questioned due to increased intestinal permeability and increased uptake of endotoxins into the blood, potentially resulting in inflammation and OS (Ashton et al., 2003, Baker et al., 2005). In addition, gastrointestinal symptom prevalence in ultra-endurance running events especially related to nausea, vomiting, abdominal pain and diarrhoea (Stamatakos et al., 2012). Previous investigations have verified that NSAIDs inhibit endo-prostaglandins and peroxidase, consequently, reducing the production of cytokines in the injured tissue and inhibiting inflammatory response (Rainsford, 2009). Others evidenced reported that the prolonged intake of NSAIDs enhances the lipid-reducing potential. This may be due to NSAID-dependent induction of reducing enzymes and inhibition of some oxidizing enzymes (Nawaz et al., 2021).

Studies that evaluated the performance of athletes after IBU use during strenuous exercise present conflicting and inconclusive results (Da Silva et al., 2011, de Souza et al., 2020). According to previous study (McAnulty et al., 2007), there was an increase in OS after IBU use but without any improvement in athletic performance after a 160 km run. Furthermore, no improvement in creatine kinase, oxygen consumption, pain, vertical jumps, and exhaustive running test 48 h post the muscle damage induction protocol (Da Silva et al., 2015). Additionally, they observed no improvement in running time, pace, and running speed but detected squat (−10.90%) and countermovement jump (−9.91%) reduction in individuals who used IBU before and during the TR. Furthermore, it is important to assess the beneficial and/or detrimental effects of IBU during long-distance running, since it is estimated that up to 75% of participant consume IBU (Lipman et al., 2017).

The 42-km TR includes a high degree of training conducted in harsh and rocky conditions. Instead of running down slopes, the race includes intense muscle movement and eccentric exhaustion. This appears to increase damage to muscle tissues such as cytoskeletons, sarcomeres, T-tubules, and sarcolemma (Fridén & Lieber, 2001), and amplifies tissue, kidney, and renal harm (Shin et al., 2016), inflammatory biomarkers (Comassi et al., 2015), and injury or disease occurrence (Botting, 2006, Newsham-West et al., 2010).

However, there is a lack of strong evidence to inform athletes about the efficacy of IBU (Da Silva et al., 2015, de Souza et al., 2020). More evidence is required to test the efficacy of IBU to minimize oxidative stress and muscle damage, as well as evaluating its capacity to enhance performance. This study aimed to investigate the impact of prophylactic use of IBU on markers of oxidative stress, muscle damage, and 42 km TR running performance.

Materials and methods

Study design

The randomized control trial was conducted at the 42k Challenge competition occurred at the Serra de Itabaiana National Park, Sergipe, Brazil. A total of 69 athletes enrolled in the event, and after participants provided informed consent, they were screened for eligibility, 12 male volunteer runners were randomized using a table of random numbers generated by a blind coordinator and allocated into two groups: ibuprofen (IBG: n = 6, 41.83 ± 9.30 years, 73.13 ± 14.43 kg, 1.71 ± 0.10 m, 19.9 ± 6.2% body fat) and placebo (placebo, n = 6, 40.33 ± 9.15 years, 78.48 ± 9.75 kg, 1.76 ± 0.06 m, 18.8 ± 4, 5% body fat). The inclusion criteria were men, half-marathon time between 01:45 and 02:00 hs and the absence of muscle, joint, or heart problems and hypertension in the last 5 months. The primary outcomes were prophylactic use of IBU on performance, markers of oxidative stress and muscle damage after the 42 km TR. This competition is considered 42 km high-level TR integrated into mountain routes with a maximum 700 m altitude, 3 km accumulated difference, 8 km single track, 5 km technical stretch, and 26 km trail. The high degree of technical difficulty of the test led to the withdrawal of 2 participants due to injury and 6 others because they exceed the cut-off time (9 h) (Figure 1).

Figure 1. Study flowchart.

Ethics approval

The procedures followed the regulatory norms of research involving human beings, Resolution No. 466/12 of the National Health Council, in accordance with the ethical principles contained in the Declaration of Helsinki (1964, reworded in 1975, 1983, 1989, 1996, 2000, and 2008) of the World Medical Association. For the study, all were clarified about the study, and signed the authorization (free, informed, and consented) in accordance with Resolution 510/2016 of the National Health Council, a research regulatory standard involving the use of data. The experimental procedures followed ethic standards and was approved by the Federal University of Sergipe Ethics Committee CAAE -02,197,018.90000.5546 following the guidelines for data collection in humans. Procedures for venous blood collection and administration of medications were followed according to safety protocols recommended by the World Health Organization (WHO) and the Brazilian Ministry of Health (Table 1 A, B, and C).

Administration of ibuprofen, procedures, and instruments

A 400-mg IBU capsule (Advil, GSK, RJ, Brazil) was administered 15 min prior to the start of the race and again after 5 h of running for all IBG athletes.

Venous blood collection was performed from all the participants, pre and post competition, to evaluate the markers of muscle damage and OS. To evaluate the race performance and jump performance, squat jump (SJ) and countermovement jump (CMJ) were performed, and the total time of test, speed, and pace was quantified. The pace of athletes per kilometre was verified through the results of the competition using chips (RFid technology, SP, Brazil) fixed in the runners’ shoes.

Blood collection

Minutes prior to the start of the test and immediately after the end of the race, 10 ml of blood was collected. The venous puncture was performed by means of the vacuum collection system in the cubital fossa using collection tubes (InjeXvácuo_® with clot activator, Injex, SP, Brazil). After the blood collection, the serum of the participants was obtained after centrifugation for 10 min at 800 g at 4°C and, then, was separated and stored in a freezer at −80°C for further analysis. Blood collection was performed by a team of qualified nurses.

Determination of markers of tissue injury and oxidative stress

The quantification of the tissue lesion caused by the 42-km TR test was determined by the enzyme creatine kinase (CK), by means of the colorimetric measurement in a UV/VIS spectrophotometer at 340 nm using a commercial kit (Labtest_®, MG, Brazil).

The quantification of OS was determined by the TBARS lipid oxidation marker (thiobarbituric acid reactive substances) as described by Lapenna et al.,(Lapenna et al., 2001). In addition, the concentration of total sulphhydryl group (SH) were also determined as a marker of the glutathione-dependent cellular antioxidant system according to the methodology described by Faure (Faure & Lafond, 1995). The TBARS and SH results were expressed in MDA/ml serum.

Evaluation of squat jump (SJ) and countermovement jump (CMJ)

For the evaluation of the SJ and CMJ tests, the 50 × 60 cm conductive surface contact mat (Probotics Inc., USA) connected to a display (Probotics Inc., USA) was used. The height of the vertical jump, which is the time interval between loss of contact of the feet with the carpet and subsequent contact after the fall, was measured(Bosco et al., 1983).

Statistical Analysis

Results are represented as mean and standard deviation from the mean. A statistically significant difference was adopted between the samples for p < 0.05. All blood tests were performed in triplicate. After evaluating the normality of the data using the Shapiro–Wilk test, the intragroup changes were statistically evaluated using the paired t test for a single sample to verify the effect of exercise on muscle damage markers and OS, and the intergroup changes by the t test unpaired for multiple samples to assess the effect of IBU on muscle damage markers and post-exercise OS. To assess the effect size, Cohen’s d test was used, adopting cut-off points of 0.02–0.15 for small effect, 0.16 to 0.35 for medium effect and greater than 0.35 like big effect. version 7.0 (GraphPad Software, San Diego, CA, USA) was used.

Results

In evaluating the baseline and placebo, a reduction in the vertical jump score was observed, with −44% (t = 3,654; p < 0.0001; Cohen’s d = 3.80) and −36% Placebo vs. IBG (t = 3,521p < 0.0001, Cohen’s d = 1.41) for SJ (Figure 2A). However, no difference in the CMJ (t = 2,141; p = 0.233, Cohen’s d = 0.32) (Figure 2B), pace (t = 1,866; p = 0.283, Cohen’s d = 0.41), speed (t = −2,112; p = 0.197, Cohen’s d = 0.23), and finish time (t = 0,586; p = 0.281, Cohen’s d = 0.20) were noted (Figure 3A, B, and C).

Figure 2. Effect of 42-km trail running (TR) test on jump performance. (A) SJ: squat jump (B) CMJ: Countermovement jump. IBG: Ibuprofen group. * p < 0.001.

Figure 3. Effect of ibuprofen on race performance after 42-km trail running (TR) test. (A) Pace, (B) Speed, and (C) Finish time; IBG: Ibuprofen group.

A 70.1% increase (t = −5,676; p < 0.0001; Cohen’s d = 4.77) was evidenced in the OS TBARS marker after the TR test in the Placebo (Figure 4A) together with the reduction of the endogenous antioxidant defence system dependent on glutathione SH in the order of 40.1% (t = −2,885; p < 0.0001; Cohen’s d = 1.06) (Figure 4B), there was also an increase in glutathione system 31.41% (t = −2,607; p = 0.024; Cohen’s d = 0.27) in the IBG group compared to the placebo group.

Figure 4. Effect of trail running (TR) test on oxidative stress markers. (A) TBARS: Thiobarbituric acid reactive substances (B) SH: Derivatives of sulphhydryl. IBG: Ibuprofen group. **** p < 0.001; * p < 0.05.

At the end of the race, a significant increase of 303% (t = −4,655; p < 0.0001; Cohen’s d = 1.41) of the CK tissue injury marker in muscle tissue was observed in relation to the baseline moment; however, no muscle tissue damage was observed with IBU administration (Figure 5A).

Figure 5. Effect of 42-km trail running test (TR) on the creatine kinase (CK) muscle damage marker. * p < 0.01. IBG: Ibuprofen group.

Discussion

The aim of this study was to evaluate the effect of IBU use on variables of oxidative stress, muscle damage, physical performance, and vertical jump of race participating in the 42 km trail run. The main findings of the present study were as follows: (1) The use of IBU had a significant effect on oxidative stress as well as on SJ and (2), in contrast IBU had no influence on physical performance.

Was observed that both the prophylactic use of IBU and the intensity of the test was able to resynthesize and re-establish the losses of electrons. Possibly activating the the antioxidant defence system after 42 km. Homoeostasis by lipid peroxidation was manifested in the overall results compared to IBG vs. Placebo, elevation of sulphhydryl derivatives, and vertical jump in IBG, in contrast with increased TBARS and CK when IBU was not ingested. This analysis proposes an adaptive response mediated by NSAIDs during moderate long-term exercise.

The possible protection against fatigue protocols shares a common link between anti-inflammatory action and overproduction of ROS (Lima et al., 2016), since there is an enzymatic inhibition of cyclooxygenase-1 and both cyclooxygenase-2 after the use of NSAIDs (Botting, 2006). This use blocks the oxidative cascade of arachidonic acid, diminishing the expression of the proinflammatory enzymes (Rainsford, 2009), and reducing the production of OS and EROs. The elevation of the SH group corroborated this analysis, favouring the endogenous protection of ROS, after altering enzymatic functions in the oxidative signalling pathway (Finkel, 2012), and establishing endoantioxidant action (i.e. glutathione) on the oxidative balance (Harris & Hansen, 2012).

Paradoxically, IBU use is controversial, since there is an inhibition of prostaglandins (Rainsford, 2009) and the absence of proprioceptive activation of pain, which makes it difficult to detect for the presence of lesions. However, ultra-running trials provoke high rates of muscle injury (Kłapcińska et al., 2013), especially on slow-twitch fibres (Zimowska et al., 2017), regardless of the age or the experience of the runners (Jastrzȩbski et al., 2015), which questions the efficacy of IBU use in increasing athletic performance. In the present study, there was no evidence of improvements in performance (pace, running speed and running time) and muscle damage (CK) in the IBG group, indicating that IBU was not able to prevent tissue damage in the sample.

It appears that the OS do not directly relate of the performance results. Oxidative stress was reduced in the IBG, but it was not accompanied by significant improvement in performance. Furthermore, together with the concentration CK data in this group, it could be speculated that the masked pain might result in increased damage during running activities. This result corroborates with the studies by de Souza et al. (2020) that do not identify improvement in CK concentration related to physical performance after the race regardless of the use of IBU.

The lack of control in NSAID use may still result in poor performance, as high doses were related to muscle strength impairment and hypertrophic adaptations in muscle gene and protein expression after 8 weeks of resistance training in young adults (Lilja et al., 2018). A dose-dependent relationship of anti-inflammatory drugs was suggested for the maximization of growth or muscle strength. In contrast, this study failed to identify improvement in physical performance but was able to observe increase in SJ score with IBU use, reiterated by the pre-race vs post-race reduction of the placebo runners. This fact can be favourable evidence, as SJ and CMJ are less affected by fatigue. This was justified in previous trials because IBU relieves gastrocnemius muscle pain by maintaining the SJ score at the end of the 42-km race (de Souza et al., 2020), as evidenced by the attenuation of isometric contraction of the quadriceps and eccentric torque 24 h after physical exercise (Lecomte et al., 1998).

However, despite the relevance of the results, the present study has some limitations: The sample size was relatively small, a follow-up on competitors was not done 24 and 48 h after the competition, which may restrict the experimental analysis. Others studies are suggested, attentive to the adverse effects related to the use of NSAIDs during the race, since gastrointestinal symptoms including nausea, reflux, dyspepsia, and abdominal pain are extremely common, evidenced gastrointestinal mucosal damages (An et al., 2020, Stamatakos et al., 2012).

Conclusion

Therefore, the presented use of IBU evidences a significant improvement in but no influence on physical performance and muscle injury in runners after 42 km run. Although the sulphhydryl and TBARS variables show consistent results for OS analysis, further investigations should be conducted to evaluate the effect of IBU on endogenous antioxidant enzymes such as catalase, superoxide dismutase, and glutathione peroxidase.

Acknowledgement

We would like to thank the Coordination Post-Graduation Program ofPhysical Education, Federal University of Sergipe (UFS) and the members ofGroup of Studies and Research of Performance, Sport, Health and ParalympicSports (GEPEPS) and Racing Club UFS.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.