One experience that unites active people, athletes, and non-athletes, is the onset of muscle pain or soreness from intense exercise. It’s accepted that delayed onset muscle soreness (DOMS) occurs when the body is repeatedly exposed to demanding or unaccustomed exercise or high-intensity eccentric muscle contractions. In general, DOMS continues to increase after exercise, peaking between 24 to 72 hours afterwards.
The mechanisms are being researched, but DOMS is a major cause of reduced exercise performance, loss of muscle strength, and range of motion, and is a common reason for continual psychological discontent.
Improving the body’s recovery capabilities is receiving ever more emphasis by researchers and practitioners such as performance specialists, coaches, and trainers. The following four approaches cover some of the latest recovery techniques proposed to reduce exercise-induced inflammation, soreness, and improve adaptation and future exercise performance.
1. Temperature-Based Strategies
Cold Water Immersion (CWI)
Cooling has been suggested to have a number of physiological effects including drop in muscle temperature, reduced muscle damage and inflammation, reduced heart rate and cardiac output, vasoconstriction and reduced edema formation, and analgesic effects. However, the actual mechanisms underlying these benefits are still uncertain.
Although there is no gold standard temperature protocol, a typical recommendation for cold water immersion (CWI) is to cool the water to 5-15°C (41-59°F). In a meta-analysis of 21 studies, the average improvement in performance measures (such as endurance, strength, sprint, and jump) was 2-3%. It’s worth noting that the beneficial effects of cooling on recovery have been greater for resistance exercise situations (i.e. eccentric weight-bearing exercise) compared to endurance exercise situations and sports (i.e. swimming and cycling). Although many cooling methods exist, the best outcomes have been reported with CWI over other forms of cooling such as ice packs, ice vests, and ice towels.
The change to muscle temperature could explain how CWI helps recovery, but it has been proposed that another mechanism may be also involved: the effect of hydrostatic pressure. Hydrostatic pressure gradients are induced by the body’s immersion in water, causing a fluid shift or “squeeze” within the body from the interstitial compartment (the space that bathes the cells of tissues) to the intravascular compartment (the blood). This fluid shift from one compartment to the other may reduce edema and muscle inflammation and damage. The increase in hydrostatic pressure results in a rise of central blood volume and cardiac output, increasing blood flow and clearance of waste products. This may explain why cooling packs or vests have not shown recovery potential–the area they’re cooling may be too small to elicit any hydrostatic pressure changes.
Whole-Body Cryotherapy (WBC)
Cheeky cryodip, anyone? A new cooling technique called whole-body cryotherapy (WBC), using a cryogenic chamber or “cryosauna” has become increasingly popular with the athletic elite.
Studies have investigated the influence of short exposures to cold dry air temperatures below -110°C (-116°F). Although few studies exist on the effect of cryotherapy technology, and more research is needed, the use of -110°C to -140°C (-116°F to -220°F) in an environmentally-controlled room for short durations (approximately 3-5 minutes) immediately post-exercise may have positive effects on recovery. During exposure, individuals wear minimal clothing, gloves, a headband covering the ears, a nose and mouth guard, and dry slippers and socks to reduce any risk of cold-related injury. I did it. It was cool…both literally and figuratively!
A recent review by Banfi et al. found evidence that WBC can change important physiological parameters. These include decreases in proinflammatory cytokines (signaling molecules that regulate or promote the inflammatory response), adaptive responses in antioxidant status, and positive effects on markers of muscle damage. Although there have been some evidence that WBC improves the perception of recovery and muscle soreness after various exercises and sports, the translation to enhanced functional recovery or performance benefits is not yet known. Cryotherapy labs have begun to emerge with single sessions costing around $70. To get your hands on your own cryosauna will cost upwards of $50,000, and until more data becomes available on the comparison and respective benefits of the strategies, you may be better off (at least financially) with CWI therapy for now.
Hot water immersion (HWI)
Throughout history, warm and hot water temperatures have been use for muscle relaxation after physical exertion. The Greek philosopher Plato noted and recommended the use of hot water baths for their benefits. More recently, hot water immersion (HWI) has been shown to result in changes in circulatory, pulmonary, renal, and musculoskeletal systems also as a result of increased hydrostatic pressures. Although whole-body HWI has shown benefits compared to say the leg only, these benefits (when tested) have shown to be inferior when compared to CWI strategies. Alternating from cool to warm water however, known as contrast water therapy (CWT), has been shown to accelerate the clearance of blood lactate and creatine kinase which are markers of muscle damage and soreness. Commonly tested CWT protocols involve alternating 3–7 times between 1 min CWI and 1–2 min HWI, accumulating 6–15 min in the water.
2. Hyperbaric Oxygen (HBO)
Hyperbaric oxygen (HBO) therapy is the administration of 100% oxygen at environmental pressures above 1 atmosphere. Adopters of the strategy have ranged from medical research investigators to the competitive elite, such as swimmer Michael Phelps. It has been suggested that the use of HBO chambers could be an effective treatment for muscle damage and related inflammation. Hyperbaric oxygen treatment may work by reducing hypoxia (a condition when the body—or a certain part of the body—is low in oxygen) and enhancing blood supply in damaged tissues, attenuating oxidative damages and enhancing healing. Studies have shown promise in animal models. However, human studies involving muscle damage or sports-related injuries have not generally supported benefits of enhanced muscle recovery or repair. For example, a study by Babul et al. found no effect of exposure of human subjects, subsequent to eccentric exercise-induced muscle damage, to 100% oxygen at 2 atmospheres for 1 hour a day over 4 days, on muscle soreness, return of muscle strength, muscle swelling or markers of muscle damage. HBO chambers are mainly accessible by visiting private HBO therapy clinics, which are becoming increasingly accessible for exercise recovery purposes. A 1 hour session will cost around $100-150, and to get your own new HBO chamber would run just over $20,000.
3. Compressive Clothing
In recent years, the use of compressive clothing has boomed with athletes not only for the fashion forward but also for those that hope to reduce injury, enhance performance, and speed recovery. The recovery benefits as reported in the literature are similar to those reported for hydrotherapy, as compressive clothing create hydrostatic pressures that perform in a similar way. Benefits stem from the graduated pressure that extends medially from the limb extremities towards the body’s core. Studies have indicated that compression garments may reduce muscle soreness, as well as aid recovery of muscle damage. Furthermore reduced perception of fatigue and clearance of blood lactate and creatine kinase (markers of muscle damage and soreness) have also been reported.
4. Nutritional Strategies
The benefits of targeted protein intake, carbohydrate replacement, and rehydration strategies have been well reported for their muscle recovery attributes and are beyond the scope of this article. In relation to improvement of muscle damage and inflammation, nonsteroidal anti-inflammatory drugs (NSAIDS) like ibuprofen, indomethacin, Vioxx, and Celebrex are the most commonly used drugs by athletes of all levels used to improve performance by alleviating muscle pain and reducing debilitating inflammation and soreness as a result of intense exercise.
However, research of functional or “bioactive” food components found in plants (known as phytochemicals or phytonutrients) that target exercise recovery has gained great momentum in recent years. Some phytonutrients, which are free of undesirable side effects, have been reported to have powerful anti-inflammatory properties and are being investigated by researchers as potential recovery aids following exercise.
Certain phytonutrients like curcumin, quercetin, EGCG, ellagitannins, and anthocyanins have well-documented anti-inflammatory activities, and their role is now being investigated in humans in the recovery of exercise-induced inflammation and delayed onset muscle soreness (DOMS). Of these promising ingredients, studies have reported that spice-derived curcumin (found in turmeric) may reduce the extent of muscle damage and DOMS following intense exercise. Quercetin (found in foods such as apples, onions, and blueberries), much like curcumin, has relatively powerful anti-inflammatory activity given its ability to inhibit the activation of the proinflammatory “master controller” NF-kB. Ellagitannins and anthocyanins (similar large phytochemicals found in pomegranates and tart cherries) have also shown great promise. For example, an ellagitannin-rich pomegranate extract was shown to improve markers of muscle damage and strength recovery after intense eccentric exercise. Similar results of improvement has been reported by multiple researchers with the use of anthocyanin-rich tart cherry juice.
In short, if you are looking to optimize your recovery by adopting some of the latest physical and nutritional strategies, consider a wardrobe of snug compression clothing, swapping your NSAID pills for phytonutrient-rich nutritionals, and trading in your car for a nice new cryosauna.