Recovery from exercise is an important component of any athlete's training and competition program. Indeed, to attenuate the fatiguing effects of strenuous exercise, numerous recovery strategies such as hydrotherapy (26,27), compression garments (18), massage (17), and active recovery (20) are commonly used by athletes of all levels. It has been suggested that accelerating the recovery process may improve subsequent performances, maximize training quality/quantity, and prevent injury or illness (19).
Vascular occlusion (OCC) (5) and sequential intermittent pneumatic compression (SIPC) are 2 recovery aids that are available commercially and increasingly being used by athletes because of their portability and ease of use compared with traditional recovery methods (such as hydrotherapy) (Figure 1). Briefly, OCC consists of repeated brief periods (several minutes) of blood flow restriction and reperfusion on targeted limbs and is usually implemented by a large blood pressure cuff (5,15). Sequential intermittent pneumatic compression devices consist of inflatable boots, which enclose the foot to the upper thigh. A series of compartments in the boot inflate sequentially from distal to proximal and remain pressurized until all compartments are inflated before simultaneously deflating and restarting the inflation sequence. Both OCC and SIPC have clinical origins, which provide direction to their potential use as recovery tools after exercise (1,6,9,16).
The proposed beneficial effects of OCC on exercise performance and recovery have been attributed to postocclusion increases in blood flow associated with elevated adenosine levels (22) and activation of ATP-sensitive potassium channels (15), which potentially result in elevated blood flow and enhanced skeletal muscle contractile function (5). Whereas, devices that apply pneumatic compression, like SIPC (which are used in the clinical treatment of deep vein thrombosis, venous insufficiency, and acute musculoskeletal injuries (1,9)), may provide a recovery benefit from exercise as they decrease swelling and edema, as well as elevating blood flow and improving emptying of lower extremity veins (25).
Despite anecdotal support of these 2 techniques by athletes, there are relatively few scientific published studies on their effectiveness for enhancing recovery from exercise. Beaven et al. (5) investigated effects of OCC as a recovery strategy after a repeated sprint task. Although limited to a few specific measures, it was reported that improvements in countermovement jump (CMJ) and squat jump (SJ) variables were observed when compared with a control group. In contrast, in an investigation examining the recovery benefits of a compression boot that inflated and deflated in a peristaltic manner (i.e., the entire boot inflates simultaneously rather than sequentially), the authors reported that this form of pneumatic compression provided no benefit on recovery after eccentric-type exercise (11). Although compression garments are commonly used for recovery, the literature is unclear as to their effectiveness, with criticisms directed towards the type and degree of compression they apply (23). Sequential intermittent pneumatic compression devices, because of their pneumatic compression, are able to exert a greater degree of pressure (∼80 mm Hg) on the targeted limb compared with compression garments (∼15–30 mm Hg) (23). Interestingly, in a clinical setting, compression applied in a sequential manner, like SIPC, is the most effective mode of pneumatic compression for clinical use (1,10). As such, the SIPC device, rather than peristaltic, may be more effective at enhancing recovery from exercise in an athletic population.
To our knowledge, no previous study has investigated the effects of OCC or SIPC on recovery from resistance exercise. The highly demanding nature of resistance exercise results in temporary acute decreases in muscle strength and power through the buildup of metabolites, mechanical damage to the muscle architecture, and impaired neuromuscular function (18,20). Therefore, the aim of this study was to examine the effects of OCC and SIPC (compared with a passive control) on muscle strength and power variables after a resistance training bout.
Experimental Approach to the Problem
To examine the effects of OCC and SIPC (compared with a passive control) on muscle strength and power variables after a resistance training bout, participants were required to complete a familiarization trial followed by 3 experimental conditions separated by at least 1 week (Figure 2). This study implemented a counterbalanced cross-over design. For each experimental condition, participants performed a fatiguing bout of resistance exercise with a series of performance and perceptual measures assessed before exercise, immediately after exercise, and 1 hour and 24 hours after exercise (Figure 2). After the postexercise performance measures, participants were assigned to 1 of the 3 different recovery interventions: (a) OCC, (b) SIPC, or (c) passive control (CON) (Figure 2). The recovery condition was not revealed to the participant until after the postexercise measures.
Participants performed all trials at the same time of day to minimize any circadian influences and were instructed to refrain from any form of exercise 24 hours before and 24 hours after the fatiguing resistance exercise bout. Alcohol was to be avoided 48 hours prior and caffeine 3 hours before each visit to the laboratory. Dietary intake was controlled by having participants record their normal diet throughout the first trial. To standardize energy intake during the recovery period, participants consumed the same self-selected postworkout snack at the beginning of each recovery period. The principal investigator monitored the diet diary to ensure that the diet was replicated during subsequent conditions.
Twelve healthy males with at least 2 years of training history, partaking in resistance exercise at least 3 times per week, volunteered to participate in the study, which was conducted during the winter months (southern hemisphere). Mean (±SD) age, height, and body mass were 24.0 ± 6.3 years (age range: 20–35 years), 180.4 ± 9.7 cm, and 84.8 ± 9.6 kg, respectively. Participants were considered well trained and had a mean three repetition maximum (3RM) of 138.3 ± 29.1 kg for a back squat. The study obtained prior ethics approval from the Australian Institute of Sport Research Ethics Committee and the Committee for Ethics in Human Research at the University of Canberra following the guidelines of the Declaration of Helsinki of the World Medical Association. Participants were informed of the benefits and risks associated with the study and provided informed written consent before participation.
The familiarization trial consisted of a standardized warm-up, the performance tests, as well as exposure to the OCC protocol and 10 minutes of the SIPC protocol. To determine the initial load for the exercise bout, a 3RM back squat test was also completed. The standardized warm-up consisted of 5-minute cycling at 60 W on a cycle ergometer (Monark, Varberg, Sweden) followed by a dynamic warm-up of 10 lunges and squats followed by 3 SJs and CMJs.
Fatiguing Resistance Exercise Bout
The fatiguing resistance exercise bout consisted of 100 back squats performed as 10 sets of 10 repetitions, with an initial resistance of 70% predicted 1RM. Predicted 1RM was determined from the 3RM back squat performed during the familiarization trial (predicted 1RM = [3RM/0.93] × 100) (3). During the movement, the bar was placed on the participants shoulders, feet under the bar, and legs fully extended. The bar was lowered until a knee angle of 90° was reached and then returned to the starting position. Any time the participant was unable to complete the target number of repetitions for a set without the assistance of a spotter, the load was decreased by 5% of the initial load for the following sets. The exercise bout was performed with no rest between repetitions and 3-minute rest between sets. Similar exercise bouts have been used successfully to induce muscle fatigue (7,8,14). Total lifting volume (total lifting volume = [weight] × [repetitions] × [sets]) was calculated for each exercise bout. On completion of the exercise bout, participants were asked a series of questions related to their effort (“How much of yourself did you give?”) using a modified Borg's scale where effort less than 100% is reported, and motivation (How motivated were you today?) and sensation (How hard was the exercise bout today?) presented as 5-point Likert scales (1 = most positive and 5 = least positive response) (13,24).
After postexercise outcome measures, participants undertook 1 of the 3 recovery strategies. First, CON—participants lay in a comfortable supine position for 45 minutes; second, OCC—participants lay in a comfortable supine position with a unilateral occlusion cuff (Flexiport Reusable Blood Pressure Cuff., Welch Allyn, Australia) fitted to the proximal portion of the leg and inflated to 220 mm Hg to induce an ischemic state. After 3 minutes, the cuff was alternated to the other leg for a further 3 minutes, before being repeated on each leg (totaling 12 minutes). The protocol used in this study is similar to that of Beaven et al. (5). Following the occlusion protocol, participants remained supine for 33 minutes; third, SIPC—participants lay in a comfortable supine position with Recovery Boots (RecoveryPump, LLC., USA) fitted to each leg. Using the manufacturer's guidelines for postexercise recovery, the 4 chambers were inflated sequentially to a pressure of 80 mm Hg with a deflation time of 15 seconds for 45 minutes in total.
Performance and Perceptual Measures
The performance and perceptual measures were measured/recorded before exercise, immediately after exercise, and 1 hour and 24 hours after exercise (Figure 2).
Participants were seated on an isokinetic dynamometer (Humac Norm, Model 770; Computer Sports Medicine, Inc., Stoughton, MA, USA) and secured with straps across the chest, hips, and tested leg to isolate movement to the quadriceps. The highest isokinetic peak torque obtained from 5 maximal voluntary contractions of the nondominant leg at 30 degrees per second was recorded, as previously described (14). Three submaximal and 1 maximal practice repetitions acted as a warm-up, and a rest period of 30 seconds was allowed between contractions. Visual feedback, displaying real-time force, and verbal encouragement were used to encourage maximal effort.
Participants performed a set of 4 static SJs. The SJ was performed from a squat position with knees bent at approximately 90°. The participants held this position for 3 seconds before jumping vertically for maximum height (2). Participants then performed a set of 4 CMJs. Participants were instructed to make a downward countermovement to a self-selected half-squat position and then jump vertically for maximum height in 1 continuous movement (2). Two-minute rest separated the SJ and CMJ tests, and a 10-second rest interval was enforced between each jump repetition (2).
All jumps were performed with a wooden broomstick held across the upper deltoids to accommodate performance quantification using a Gymaware optical encoder (50-Hz sample period; Kinetic Performance Technology, Canberra, Australia). Jump height (in centimeter) was measured for each SJ and CMJ (7). Data traces were checked visually for errors by the principal investigator after each set of four jumps.
Perceptual Measures of Recovery
After the standardized warm-up and before undertaking the muscle dynamometry, participants' perceived recovery and muscle soreness were recorded. The perceived recovery status (PRS) scale (21) is a modified Borg's CR10 scale and measures the participants' perceived recovery (0 = very poorly recovered, 10 = very well recovered). Borg's CR10 scale was also adapted to measure muscle soreness (0 = nothing at all, 10 = extremely high), as described previously (27,28). The participants performed a standardized half squat before assessing muscle soreness (28).
Recovery Protocol Rating
Within 5 minutes after recovery, the participant was asked to rate each recovery strategy on a 5-point Likert scale (1 = like very much and 5 = dislike very much). This scale has been used previously to subjectively measure the participant's perception of a recovery protocol (13).
Parametric data are presented as mean ± SD, and statistical significance was set at p ≤ 0.05. A 2 factor repeated-measures analysis of variance was used to determine changes in performance outcomes (condition [OCC, SIPC, and CON] and time [pre, post, 1 hour post, and 24 hours post]) and to identify week-to-week differences in the total lifting volume during the fatiguing resistance exercise bout and between the different recovery conditions. When sphericity was violated, Greenhouse-Geisser corrections were used. Where significance was found, post hoc pairwise comparisons were performed using Bonferroni's adjustment for multiple comparisons.
For nonparametric data (i.e., the PRS scale, soreness scale, and RPE), Friedman's tests were conducted to determine differences in perceptual measures for the fatiguing resistance exercise bout, recovery intervention rating, PRS scale, and soreness scale. Where results indicated a significant difference was present, post hoc Wilcoxon's signed-rank test with a Bonferroni's correction for multiple comparisons was used. All analyses were conducted using SPSS for Windows (version 21.0; IBM, NY, USA).
Concentric peak isokinetic torque at 30 degrees per second (p < 0.001) (Figure 3) decreased significantly over time. Concentric peak isokinetic torque at 30 degrees per second was significantly higher at 24 hours compared with post (p = 0.003), but there were no significant differences in peak torque between conditions (p = 0.561) (Figure 3).
Mean vertical jump height for SJ (p < 0.001) and CMJ (p < 0.001) significantly decreased over time (Figure 4). There were no significant differences in mean jump height for SJ (p = 0.843) and CMJ (p = 0.879) between conditions (Figure 4).
Perceptual Measures of Recovery Status
Perceived recovery status decreased (0 = very poorly recovered, 10 = very well recovered) significantly (p < 0.001) over time for all 3 of the recovery conditions (Figure 5). There were no significant differences in PRS between conditions at any time point (pre [p = 0.690], post [p = 0.886], 1 hour [p = 0.406], and 24 hours [p = 0.401]). Participants perceived soreness (0 = nothing at all, 10 = extremely high) increased significantly (p < 0.001) over time for all 3 of the recovery conditions (Figure 5). There were no significant differences in perceived soreness between conditions at any time point (pre [p = 0.428], post [p = 0.735], 1 hour [p = 0.145], and 24 hours [p = 0.275]).
Recovery Protocol Rating
The OCC (mean rank = 1.92, p = 0.030) and SIPC (mean rank = 1.58, p = 0.020) recovery interventions were rated significantly higher than the control recovery intervention (mean rank = 2.50).
Fatiguing Resistance Exercise Bout
The average total weight lifted during the fatiguing resistance exercise bout was similar between conditions (OCC = 10,220.2 ± 2,100.0 kg, SIPC = 10,216.9 ± 2,211.8 kg, and CON = 10,047.3 ± 2,190.1 kg; p = 0.97). Participant ratings of effort (mean rank = 1.83–2.13 and p = 0.629–0.895) were similar between all conditions after the fatiguing resistance exercise bout.
The main finding of this study is that OCC and SIPC did not further improve recovery of muscular performance after a fatiguing resistance exercise bout relative to a passive control. Perceptual measures of recovery and muscle soreness were also not significantly different compared with the passive control, despite participants reporting that they preferred the novel recovery interventions. These findings have important implications for the use of both OCC and SIPC, as the described protocols were not effective at increasing recovery after resistance exercise.
The results of this study are consistent with the overall findings of previous recovery studies on OCC (5) and a compression boot similar to SIPC (11) that were applied in a different context. Beaven et al. (5) previously reported that the same OCC protocol used in our study did not significantly improve the recovery of maximal leg press dynamometry after a different exercise bout consisting of leg exercise (6 × leg press, 3 × SJ and 3 × CMJ) and repeated sprints. However, in contrast to this study, they did report benefits to recovery of CMJ (eccentric peak velocity) and SJ (eccentric power and eccentric peak acceleration) after strenuous exercise. Although some beneficial effects were reported, similar to this study, there was no statistically significant difference in recovery of CMJ and SJ mean jump height. Cochrane et al. (11) previously reported that compression boots, inflated in a nonsequential manner, did not improve recovery of peak and average concentric isokinetic torque at 30 degrees per second of the quadriceps. The same study also found no significant difference between their compression boot and a control condition on CMJ performance (11).
In this study, participants' rating of PRS remained reduced and muscle soreness elevated significantly at 24 hours compared with baseline, indicating that muscle damage may still have been present (18). Postexercise swelling, contributing to the stimulation of pain afferents, peaks intramuscularly at 24–48 hours after exercise (12,18). It is possible that OCC or SIPC may have benefits beyond the 24-hour recovery window reported in this study.
The participants in our study were well trained in resistance exercise, and many of the actions associated with resistance exercise have a considerable eccentric bias (4). A repeated bout effect, after eccentric muscle actions, is associated with improved recovery of muscle function and decreased soreness after similar exercise (4). Consequent to the fatiguing resistance exercise bout used in our study, muscle force was attenuated at post (−15%), 1 hour (−11%), and 24 hours (−4%) compared with baseline. In comparison, when untrained participants have previously completed a similar fatiguing resistance exercise bout and the same performance test as our study, muscular force was still reduced by 21% after 24 hours (14). The repeated bout effect may explain why our participants were able to better reproduce performance after the fatiguing resistance exercise bout compared with an untrained population (14). A greater degree of fatigue may have allowed a greater scope for the recovery strategies to show an improved recovery profile compared with the control condition.
Differences in clinical outcomes showing positive results and the lack of substantial benefits from adopting OCC and SIPC recovery strategies in our study may also be due to the treatment duration. For example, clinical treatment with SIPC can involve multiple applications per day, up to a total of 3 hours and often combined with other specific pharmacological or physical treatments (11,25). Hence, after the fatiguing exercise, SIPC protocols with longer treatment duration or multiple treatments per day may offer improved recovery effects. However, it is important to consider that increasing the duration and number of treatments may decrease the practicality of SIPC to an athlete.
The current investigation showed no benefit of SIPC and OCC after fatiguing a back squat training session. It should be noted, however, that both SIPC and OCC can be altered such that other protocols with varied pressures, durations, or pauses can be performed. As there are no clear guidelines for either of the devices for recovery, future research using modified protocols, or in combination with other recovery strategies (e.g., active recovery), may offer alternative uses for both of these portable devices.
Furthermore, the physiological changes associated with SIPC and OCC may be of benefit to recovery from other types of exercise. For example, both recovery devices, either directly or by underlying mechanisms, increase blood flow. Increased blood flow has been assumed to be an underlying mechanism of commonly used recovery protocols through the repletion of ATP and the increased removal of metabolic byproducts after cycling (26) and team sport (19). As such, exercise where the predominant source of fatigue may be through depletion of muscle glycogen or accumulation of metabolic byproducts, for instance, may benefit from these 2 potential recovery strategies. Future research into the application of these portable recovery strategies would be required to ascertain their effectiveness on recovery from other modes of exercise.
Despite anecdotal support for these 2 techniques, this study indicates that neither strategy was able to expedite the recovery of muscular performance or perceptual measures any further than passive rest after a fatiguing bout of resistance exercise.
The authors would like to acknowledge the efforts of the study participants. The results of this study do not constitute endorsement of the product by the authors or the National Strength and Conditioning Association.
1. Airaksinen O, Kolari PJ, Miettinen H. Elastic bandages and intermittent pneumatic compression for treatment of acute ankle sprains. Arch Phys Med Rehabil 71: 380–383, 1990.
2. Argus CK, Gill ND, Keogh JWL, McGuigan MR, Hopkins WG. Effects of two contrast training programs on jump performance in rugby union players during a competition phase. Int J Sports Physiol Perform 7: 68–75, 2012.
3. Baechle TR, Earle RW. Essentials of Strength Training and Conditioning. Champaign, IL: National Strength and Conditioning Association, 2008. pp. 397.
4. Barnett A. Using recovery modalities between training sessions in elite athletes: Does it help? Sports Med 36: 781–796, 2006.
5. Beaven CM, Cook CJ, Kilduff L, Drawer S, Gill N. Intermittent lower-limb occlusion enhances recovery after strenuous exercise. Appl Physiol Nutr Metab 37: 1132–1138, 2012.
6. Bøtker HE, Kharbanda R, Schmidt MR, Bøttcher M, Kaltoft AK, Terkelsen CJ, Munk K, Andersen NH, Hansen TM, Trautner S. Remote ischaemic conditioning before hospital admission, as a complement to angioplasty, and effect on myocardial salvage in patients with acute myocardial infarction: A randomised trial. Lancet 375: 727–734, 2010.
7. Byrne C, Eston R. The effect of exercise-induced muscle damage on isometric and dynamic knee extensor strength and vertical jump performance. J Sports Sci 20: 417–425, 2002.
8. Byrne C, Eston R. Maximal-intensity isometric and dynamic exercise performance after eccentric muscle actions. J Sports Sci 20: 951–959, 2002.
9. Chen AH, Frangos SG, Kilaru S, Sumpio BE. Intermittent pneumatic compression devices—Physiological mechanisms of action. Eur J Vasc Endovasc Surg 21: 383–392, 2001.
10. Chleboun GS, Howell JN, Baker HL, Ballard TN, Graham JL, Hallman HL, Perkins LE, Schauss JH, Conatser RR. Intermittent pneumatic compression effect on eccentric exercise-induced swelling, stiffness, and strength loss. Arch Phys Med Rehabil 76: 744–749, 1995.
11. Cochrane DJ, Booker HR, Mundel T, Barnes MJ. Does intermittent pneumatic leg compression enhance muscle recovery after strenuous eccentric exercise? Int J Sports Med 34: 969–974, 2013.
12. Connolly DAJ, Sayers SP, McHugh MP. Treatment and prevention of delayed onset muscle soreness. J Strength Cond Res 17: 197–208, 2003.
13. Cook CJ, Beaven CM. Individual perception of recovery is related to subsequent sprint performance. Br J Sports Med 47: 705–709, 2013.
14. Davies RC, Eston RG, Poole DC, Rowlands AV, DiMenna F, Wilkerson DP, Twist C, Jones AM. Effect of eccentric exercise-induced muscle damage on the dynamics of muscle oxygenation and pulmonary oxygen uptake. J Appl Physiol (1985) 105: 1413–1421, 2008.
15. De Groot PCE, Thijssen DHJ, Sanchez M, Ellenkamp R, Hopman MTE. Ischemic preconditioning improves maximal performance in humans. Eur J Appl Physiol 108: 141–146, 2010.
16. Eisen A, Fisman EZ, Rubenfire M, Freimark D, McKechnie R, Tenenbaum A, Motro M, Adler Y. Ischemic preconditioning: Nearly two decades of research. A comprehensive review. Atherosclerosis 172: 201–210, 2004.
17. Ernst E. Does post-exercise massage treatment reduce delayed onset muscle soreness? A systematic review. Br J Sports Med 32: 212–214, 1998.
18. French DN, Thompson KG, Garland SW, Barnes CA, Portas MD, Hood PE, Wilkes G. The effects of contrast bathing and compression therapy on muscular performance. Med Sci Sport Exerc 40: 1297, 2008.
19. Gill ND, Beaven CM, Cook C. Effectiveness of post-match recovery strategies in rugby players. Br J Sports Med 40: 260–263, 2006.
20. Kraemer WJ, Ratamess NA. Fundamentals of resistance training: Progression and exercise prescription. Med Sci Sport Exerc 36: 674–688, 2004.
21. Laurent CM, Green JM, Bishop PA, Sjökvist J, Schumacker RE, Richardson MT, Curtner-Smith M. A practical approach to monitoring recovery: Development of a perceived recovery status scale. J Strength Cond Res 25: 620–628, 2011.
22. Liu GS, Richards SC, Olsson RA, Mullane K, Walsh RS, Downey JM. Evidence that the adenosine A3 receptor may mediate the protection afforded by preconditioning in the isolated rabbit heart. Cardiovasc Res 28: 1057–1061, 1994.
23. MacRae BA, Cotter JD, Laing RM. Compression garments and exercise garment considerations, physiology and performance. Sports Med 41: 815–843, 2011.
24. Ross M, Garvican LA, Jeacocke NA, Laursen PB, Abbiss CR, Martin DT, Burke LM. Novel precooling strategy enhances time trial cycling in the heat. Med Sci Sport Exerc 43: 123, 2011.
25. Sheldon RD, Roseguini BT, Thyfault JP, Crist BD, Laughlin MH, Newcomer SC. Acute impact of intermittent pneumatic leg compression frequency on limb hemodynamics, vascular function, and skeletal muscle gene expression in humans. J Appl Physiol (1985) 112: 2099–2109, 2012.
26. Vaile J. Effect of cold water immersion on repeated cycling performance and limb blood flow. Br J Sports Med 45: 825–829, 2011.
27. Vaile J, Halson S, Gill N, Dawson B. Effect of hydrotherapy on the signs and symptoms of delayed onset muscle soreness. Eur J Appl Physiol 102: 447–455, 2008.
28. Versey NG, Halson SL, Dawson BT. Effect of contrast water therapy duration on recovery of running performance. Int J Sports Physiol Perform 7: 130–140, 2012.