Exercise-induced muscle damage (EIMD) after eccentric contractions is a well described condition, which is clinically marked by functional impairments, such as decreased maximal force production capacity, changes in force production optimal length, increased passive tension, and muscle edema.1, 2, 3 These changes may lead to limitation of athletic performance4, 5 and increased risk of injury.6

The muscle function recovery after damage events is a relevant issue and has attracted attention of many researchers, physical therapists and athletic coaches. Aiming to fostering muscle recovery, contrast water therapy, cryotherapy with ice bags or cold water immersion, low intensity active exercise, phototherapy, massage and compression garment are some recovery strategies employed.5, 7, 8, 9, 10, 11, 12

The use of compressive garments to improve the muscle recovery has shown promising results.10, 12, 13 There are evidences that this treatment modality may promote a more rapid recovery of muscle function, and reduced post-exercise muscle soreness and swelling,12, 14 with potential benefits mediated via physical, physiological or psychological effects, although underlying mechanisms are not well elucidated.14

Despite the promising results, it should be noted that the large majority of studies where the compressive garments are employed involve lower limb. In a recent meta-analysis, Hill et al.12 listed twelve studies that achieved established criteria and only three of them13, 15, 16 included the use of compression sleeve worn after damage exercises of upper arm. Interestingly, in these studies the compression sleeve was worn for 72 or 120 h following damaging exercise, while there are studies reporting effective results wearing compression stockings by only 12 h following lower limb damaging exercises.9, 10, 17

It is important to note that the post-exercise recovery strategies should not only be effective, but also promote treatment adhesion, which involves the treatment time necessary to achieve effective results. Notwithstanding, treatment periods of 72 h or more seem to be long, while treatments for short periods, as 12 h, may improve the treatment adhesion, but, to our knowledge, there are no studies that have investigated the efficacy of compression sleeve worn for short-time periods, as 12 h, on recovery from the symptoms of EIMD from upper arm muscles. This issue gains relevance because upper body exercise results in greater levels of muscle damage and soreness than lower body exercise.18, 19, 20 Then, it is possible to hypothesize that the use of compression sleeves by short-time periods may not be sufficient to promote an effective recovery as observed when compression garments are applied for lower-body.

Therefore, this study was carried out to assess the efficacy of compression sleeve worn for short-time periods (12 h), on recovery from the symptoms of EIMD from upper arm muscles.

In a randomized controlled study, thirteen subjects, without previous experience with eccentric exercises and who had not performed regular resistance training in the past 6 months, provided informed consent to participate in this study. Ethical approval (protocol # 06615313.8.0000.0055) was provided by the ethics committee of the State University of Southwest Bahia, according to the Declaration of Helsinki.

Subjects were screened to confirm that they had no neuromuscular diseases and musculoskeletal problems for the non-dominant upper extremity before the study's beginning. Additionally, they were asked to refrain from unaccustomed exercise or vigorous physical activity and not to take any anti-inflammatory drugs or other therapeutic modalities during the experimental period.

This study was designed to verify the effect of a compressive sleeve, donned immediately after an eccentric exercise bout, on muscle recovery. Subjects were randomly placed into two groups: TREATED (n = 7) and CONTROL (n = 6), and no significant differences in age, height, body mass were evident between the groups. A crossover experimental design was not used because of the frequent reports about the protective effect promoted by repeated bouts of eccentric exercise.3, 21

An eccentric exercise protocol, using weighted dumbbells, was adopted from previous studies.3, 22 To determine the dumbbell weight for eccentric exercise, each subject was requested to sit on a custom made preacher curl bench with his shoulder joint angle at 45° flexion with 0° abduction, and pull a handle attached to a load cell (EMG System, São Jose dos Campos, Sao Paulo, Brazil) using the non-dominant arm.

The elbow joint angle was set at 90°, and the subject was asked to flex the elbow joint maximally while keeping the forearm supinated. This measurement was taken three times immediately before the eccentric exercise, with a 45-s rest between trials, and the average peak force from the three trials was used to determine the dumbbell weight. No significant difference in dumbbell weight was found between the groups (see Table 1).

Table 1. Mean ± SE of anthropometric characteristics, exercise load, and baseline values of muscle soreness and UAC from TREATED and CONTROL groups.

Once the load of the dumbbell was determined, the subjects were instructed to lower the dumbbell from an elbow flexion of 50° to an extended position of 170° in approximately 4–5 s, when the investigator removed the dumbbell from the arm, and the subject returned the arm to the start position for the next eccentric contraction. Subjects were verbally encouraged and guided to lower the dumbbell at a consistent velocity by following a count given by the investigator. The movement was repeated 30 times with a 45-s rest between contractions.

Immediately after the eccentric exercise bout the volunteers donned a sleeve compression (group TREATED) or no intervention (group CONTROL). Volunteers were randomized by using a simple drawing of lots (A and B), and those allocated into the lot A received a compression sleeve (group TREATED) while those into the lot B received none intervention (group CONTROL).

The subjects in the TREATED group wore the compression sleeve for 12 h following the eccentric damage protocol and were only allowed to remove for bathing to ensure that the total time out of the compression garment did not exceed 30 min. Compression sleeve was made with 90% polyamide and 10% lycra (elastane) fibers, and covered the non-dominant arm from axillary line to mid-forearm.

The dependent variables consisted of elbow flexion peak force with the elbow joint angle set at 90°, upper arm circumference (UAC) and muscle soreness. The isometric muscle strength, UAC, and muscle soreness measures were taken before and at 24, 48, 72 and 96 h after eccentric exercise.

The isometric muscle strength was recorded as described previously to determine the dumbbell weight. All isometric muscle strength measures were taken before, and at 24, 48, 72 and 96 h after the eccentric exercise bout. The highest peak force among the three trials from each day was used for statistical comparisons, and the isometric muscle strength recorded at 24–96 h after exercise bout was normalized by the measure recorded before the exercise bout to allow comparisons between groups.

Upper arm circumference was assessed at 8 cm above the elbow joint with a Gulick tape measure, while the subject was standing and allowing the arm to hang down by the side of the hips. The measurement point was marked on the subject's arm to ensure consistent placement of the tape measure, and the average value of three measurements was used for further analysis, as used by Chen et al.3 The same experienced investigator assessed the UAC over time for all subjects to ensure the reliability of measures.

The level of muscle soreness of the exercised arm was assessed using a visual analog scale (VAS) consisting of a 100-mm line representing “no pain” at one end (0 mm) and “very, very painful” at the other (100 mm). The subjects were asked to indicate the level pain on the line when the investigator extended the elbow joint maximally. The same investigator assessed the muscle soreness over time for all subjects, and the procedure was standardized as described in previous studies.3, 22

The anthropometric characteristics and exercise load (i.e., dumbbell weight for exercise bout), as well as the baseline measures of Isometric muscle strength, muscle soreness and UAC from groups were compared with unpaired student t test. For elbow flexion peak force and UAC the measures after exercise bout and intervention were normalized using each subject’ own initial baseline (i.e., measure before exercise bout and intervention) measurement as reference. Dependent variables were assessed with a two-way model analysis of variance (2 groups × 5 times) with repeated measures over time points and group as between-subjects factors to compare the normalized force, normalized UAC and VAS for the groups (TREATED and CONTROL) following exercise bout. Multiple comparisons were made according to Bonferroni's method (0.05/number of comparisons). A significance level of P < 0.05 was used for all statistical procedures. Results are presented as mean ± SE. Statistical analysis was completed using the PASW 18 statistical package (SPSS Inc., Chicago, IL).

Anthropometric characteristics and the exercise load (i.e., dumbbell weight for the exercise bout) from the TREATED and CONTROL groups were not different. Similar baseline values were also observed for muscle soreness and UAC (see Table 1).

For the normalized force, a significant main effect for measures (F4,55 = 5.51; P = 0.001) was observed. Normalized force decreased significantly after the eccentric exercise bout for both groups, reaching impairments of ∼43% and ∼34%, for CONTROL and TREATED groups, respectively, 24 h after exercise. Despite of this, a significant main effect for groups or group measure interactions was not observed (see Figure 1A).

Figure 1. Mean ± SE of normalized force (A), normalized upper arm circumference (B) and muscle soreness (C) from TREATED and CONTROL groups before (PRE), and 24, 48, 72 and 96 h after an eccentric exercise bout. *Significantly different from measure PRE (P < 0.05).

Upper arm circumference and muscle soreness showed a significant main effect for measures (F4,55 = 6.49; P < 0.001 for UAC and F4,55 = 6.95; P < 0.001 for muscle soreness), with an increase after exercise bout for both groups. Furthermore, no significant main effect for groups or group × measure interactions was observed (see Figure 1B and C).

The primary finding of this investigation was that the use of a compression sleeve for short-time period (12 h) was not effective to improve the recovery from the symptoms of EIMD from upper arm muscles. This finding is in line with our hypothesis that compression sleeve worn for short-time periods may not be sufficient to promote an effective recovery from EIMD, what diverge when lower-body compression garments are applied.

Benefits from compression garments may be mediated by creating an external pressure gradient, which partially compensate changes in osmotic pressure and reduces the space available for swelling.12, 23, 25 Despite speculative aspect of this hypothesis, it could explain positive results from compressive garments, decreasing exudates and the degree of chemotaxis, thus attenuating the inflammatory response and perceived pain.12, 23

Although the underlying mechanisms are not well elucidated, the use of compression garments to enhancing recovery from muscle damage has been recognized,12 but positive results are predominantly observed when compression garments are employed for lower limb,12 while for the upper arm there are only two studies with positive results.13, 16

Kraemer et al.16 submitted healthy young women to an upper-arm damaging exercise (elbow flexors) and allocated them into two groups, a control group (i.e., none intervention) and an intervention group, that used a compressive sleeve throughout a recovery period of 5 days (i.e., 120 h). These authors observed a significant recovery from the symptoms of EIMD (prevented loss of elbow motion, decreased perceived soreness, reduced swelling, and promoted recovery of force production), suggesting a benefic effect of compressive sleeve. However, it is important to note that, in the cited study, significant differences between groups for force production and perceived soreness were observed predominantly after the third day of recovery period, which correspond to a ∼72 h of continuous compressive sleeve use.

Similar results were found from Kraemer et al.,13 but involving healthy young men and the use of compressive sleeve for 72 h. Interestingly, Carling et al.15 found no differences in recovery from EIMD (perceived soreness, range of motion (ROM), arm circumference, and force production) of upper arms (elbow flexors) between control and compression sleeve used for 72 h.

Such results suggest a potential benefit from the use of compressive sleeve in recovery from EIMD, but it has been tested only with compression sleeves worn for long periods (i.e., 72 h or more), while many studies showed positive results when compression stockings are used for 12 h following lower limb damaging exercises.9, 10, 17

In this context, we assessed the efficacy of compression sleeves worn for short-time periods (12 h) on recovery from the symptoms of EIMD from upper arm muscles and found that it was not effective to improve the recovery. Our results confirm the suggested hypothesis that short-time periods of compression sleeve may not result in effective results as observed when lower-body compression garments are applied.

It is known that upper body exercise results in greater levels of muscle damage and soreness than lower body exercise,18, 19, 20 and this different muscle susceptibility to EIMD (mainly with eccentric actions) may result from the different architecture of arm and leg muscles,24 such that mechanical stress per muscle unit differs between these two muscle groups when performing exercises at the same intensity (i.e., a percentage of maximum).

Additionally, Jamurtas et al.18 proposed that submaximal eccentric actions of lower body muscles, such as downhill walking and descending stairs, are routinely performed during daily activities and it is well documented that, following repeated bouts of eccentric exercise, the muscles adapt to protect against further damage.26 This difference in the susceptibility to EIMD from upper and lower limb muscles may explain our findings, such that the same intervention, as the use of compressive garments, applied with the same parameters, may not produce similar outcomes. As for many other therapeutic interventions, the time to exposure or treatment may influence the outcome, and for compression sleeves, the minimum intervention period seems to be greater than 12 h. Further studies should focus on this issue: What is the minimum intervention time with compression sleeves to fostering muscle recovery after damaging exercises?

Our results, together with previous findings, suggest that 12 h of compressive garment is not enough to improve the recovery from EIMD in upper arm muscles, and longer periods of compressive garment should be necessary to achieve positive outcomes.

Authors declare that they don’t have any conflict of interests.

Acknowledgments

Mikhail Santos Cerqueira, Lucio Santos Borges and José Alberto dos Santos Rocha would like to thank Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB) and Universidade Estadual do Sudoeste da Bahia (UESB), respectively, for the scholarship concession (# 046/2012).

Received 3 June 2014

Accepted 29 July 2014

Corresponding author. rafaelpereira@brjb.com.br