The flavonoid quercetin is purported to have potent antioxidant and anti-inflammatory properties. This study examined if quercetin supplementation attenuates indicators of exercise-induced muscle damage in a doubleblind laboratory study. Thirty healthy subjects were randomized to quercetin (QU) or placebo (PL) supplementation and performed 2 separate sessions of 24 eccentric contractions of the elbow flexors. Muscle strength, soreness, resting arm angle, upper arm swelling, serum creatine kinase (CK) activity, plasma quercetin (PQ), interleukin-6 (IL-6), and C-reactive protein (CRP) were assessed before and for 5 d after exercise. Subjects then ingested nutrition bars containing 1,000 mg/d QU or PL for 7 d before and 5 d after the second exercise session, using the opposite arm. PQ reached 202 ± 52 ng/ml after 7 d of supplementation and remained elevated during the 5-d postexercise recovery period (p < .05). Subjects experienced strength loss (peak = 47%), muscle soreness (peak = 39 ± 6 mm), reduced arm angle (–7° ± 1°), CK elevations (peak = 3,307 ± 1,481 U/L), and arm swelling (peak = 11 ± 2 mm; p < .0001), indicating muscle damage and inflammation; however, differences between treatments were not detected. Eccentric exercise did not alter plasma IL-6 (peak = 1.9 pg/ml) or CRP (peak = 1.6 mg/L) relative to baseline or by treatment. QU supplementation had no effect on markers of muscle damage or inflammation after eccentric exercise of the elbow flexors.
Kevin S. O’Fallon, Diksha Kaushik, Bozena Michniak-Kohn, C. Patrick Dunne, Edward J. Zambraski and Priscilla M. Clarkson
Piotr Basta, Łucja Pilaczyńska-Szczȩśniak, Donata Woitas-Ślubowska and Anna Skarpańska-Stejnborn
This investigation examined the effect of supplementation with Biostimine, extract from aloe arborescens Mill. leaves, on the levels of pro-oxidant–antioxidant equilibrium markers and anti- and proinflammatory cytokines in rowers subjected to exhaustive exercise. This double-blind study included 18 members of the Polish Rowing Team. Subjects were randomly assigned to the supplemented group (n = 9), which received one ampoule of Biostimine once daily for 4 weeks, or to the placebo group (n = 9). Subjects performed a 2,000-meter-maximum test on a rowing ergometer at the beginning and end of the preparatory camp. Blood samples were obtained from the antecubital vein before each exercise test, 1 min after completing the test and after a 24-hr recovery period. Superoxide dismutase and glutathione peroxidase activity as well as the concentration of thiobarbituric acid reactive substances (TBARS) were assessed in erythrocytes. In addition, total antioxidant capacity (TAC) and creatine kinase activity were measured in plasma samples, and cytokine (IL-6, IL-10) concentrations were determined in the serum. Before and after Biostimine supplementation, exercise significantly increased the values of SOD, IL-6, IL-10, and TBARS in both groups. However, postexercise and recovery levels of TBARS were significantly lower in athletes receiving Biostimine than in controls. After supplementation, TAC was the only variable with the level being significantly higher in the supplemented group than in the placebo group. Consequently, we can conclude that Biostimine supplementation reduces the postexercise level of TBARS by increasing the antioxidant activity of plasma but has no effect on inflammatory markers.
J. Mark Davis, Catherine J. Carlstedt, Stephen Chen, Martin D. Carmichael and E. Angela Murphy
Quercetin, a natural polyphenolic flavonoid substance present in a variety of food plants, has been shown in vitro and in animal studies to have widespread health and performance benefits resulting from a combination of biological properties, including antioxidant and anti-inflammatory activity, as well as the ability to increase mitochondrial biogenesis. Little is known about these effects in humans, however, especially with respect to exercise performance. The authors determined whether quercetin ingestion would enhance maximal aerobic capacity and delay fatigue during prolonged exercise in healthy but untrained participants. Twelve volunteers were randomly assigned to 1 of 2 treatments: (a) 500 mg of quercetin twice daily dissolved in vitamin-enriched Tang or (b) a nondistinguishable placebo (Tang). Baseline VO2max and bike-ride times to fatigue were established. Treatments were administered for a period of 7 days using a randomized, double-blind, placebo-controlled, crossover study design. After treatment both VO2max and ride time to fatigue were determined. Seven days of quercetin feedings were associated with a modest increase in VO2max (3.9% vs. placebo; p < .05) along with a substantial (13.2%) increase in ride time to fatigue (p < .05). These data suggest that as little as 7 days of quercetin supplementation can increase endurance without exercise training in untrained participants. These benefits of quercetin may have important implications for enhancement of athletic and military performance. This apparent increase in fitness without exercise training may have implications beyond that of performance enhancement to health promotion and disease prevention.
Aimee L. Thornton, Cailee W. McCarty and Mollie-Jean Burgess
Shoulder pain is a common musculoskeletal condition that affects up to 25% of the general population. Shoulder pain can be caused by any number of underlying conditions including subacromial impingement syndrome, rotator-cuff tendinitis, and biceps tendinitis. Regardless of the specific pathology, pain is generally the number 1 symptom associated with shoulder injuries and can severely affect daily activities and quality of life of patients with these conditions. Two of the primary goals in the treatment of these conditions are reducing pain and increasing shoulder range of motion (ROM).3 Conservative treatment has traditionally included a therapeutic exercise program targeted at increasing ROM, strengthening the muscles around the joint, proprioceptive training, or some combination of those activities. In addition, these exercise programs have been supplemented with other interventions including nonsteroidal anti-inflammatory drugs, corticosteroid injections, manual therapy, activity modification, and a wide array of therapeutic modalities (eg, cryotherapy, EMS, ultrasound). Recently, low-level laser therapy (LLLT) has been used as an additional modality in the conservative management of patients with shoulder pain. However, the true effectiveness of LLLT in decreasing pain and increasing function in patients with shoulder pain is unclear.
Focused Clinical Question:
Is low-level laser therapy combined with an exercise program more effective than an exercise program alone in the treatment of adults with shoulder pain?
Robert Carter III, Samuel N. Cheuvront and Michael N. Sawka
We report our observations on one soldier with abnormal hyperthermia during exercise in the heat compared with prior exercise and following acute local (non-febrile) infection. Also, we report on 994 heat stroke hospitalizations in the U.S. Army. It is known that prior infection is a risk factor for heat illness and some of the 37 heat stroke deaths cited infections (eg, pneumonia, influenza) in the medical records.
This case report illustrates complete recovery from abnormal hyperthermia, which occurred in a laboratory setting during mild, low intensity exercise. In a field setting, this case may have resulted in serious heat illness. As with most of the heat stroke cases, rapid medical attention (ie, cooling and rehydration) and the age group (19 to 26) that represents majority of the heatstroke cases in U.S. Army are likely factors that contribute successful treatment of heatstroke in the field environment.
We conclude that acute inflammatory response can augment the hyperthermia of exercise and possibly increase heat illness susceptibility. Furthermore, it is important for health care providers of soldiers and athletes to monitor acute local infections due to the potential thermoregulatory consequences during exercise in the heat.
Keith Tolfrey, Julia K. Zakrzewski-Fruer and James Smallcombe
Three publications were selected based on the strength of the research questions, but also because they represent different research designs that are used with varying degrees of frequency in the pediatric literature. The first, a prospective, longitudinal cohort observation study from 7 to 16 years with girls and boys reports an intrinsic reduction in absolute resting energy expenditure after adjustment for lean mass, fat mass, and biological maturity. The authors suggest this could be related to evolutionary energy conservation, but may be problematic now that food energy availability is so abundant. The second focuses on the effect of acute exercise on neutrophil reactive oxygen species production and inflammatory markers in independent groups of healthy boys and men. The authors suggested the boys experienced a “sensitized” neutrophil response stimulated by the exercise bout compared with the men; moreover, the findings provided information necessary to design future trials in this important field. In the final study, a dose-response design was used to examine titrated doses of high intensity interval training on cardiometabolic outcomes in adolescent boys. While the authors were unable to identify a recognizable dose-response relationship, there are several design strengths in this study, which was probably underpowered.
Two papers were selected for this commentary. The first paper (Citation 1) suggests that a 10-week, moderate-intensity exercise program performed early after allogeneic hematopoietic stem cell transplantation is feasible in this fragile population, and might improve cell cytotoxicity by redistributing subpopulations of NK cells. This study adds to the growing evidence that enhancing immune cell surveillance (e.g., NK cells) in response to exercise could benefit cancer patients. The second paper (Citation 2) studied neutrophil-related mediators of oxidative stress and inflammatory cytokines in response to exercise in children compared with adults. The authors found age/maturation-related differences in these responses. The paper provides a valuable introduction to the current knowledge of maturational changes in immune mediators’ response to exercise. Data about leukocyte function in response to exercise in healthy children and in children with clinical conditions is scant. The need for prospective large scale pediatric clinical exercise studies is clear. Molecular approaches to understand the mechanisms through which physical activity can improve health will help to shape guidelines that optimize the mode, frequency, intensity, and duration of the training intervention.
Brian D. Tran and Pietro Galassetti
The beneficial effects of exercise, including reduction of cardiovascular risk, are especially important in children with type 1 diabetes (T1DM), in whom incidence of lifetime cardiovascular complications remains elevated despite good glycemic control. Being able to exercise safely is therefore a paramount concern. Dysregulated metabolism in T1DM however, causes frequent occurrence of both hypo- and hyperglycemia, the former typically associated with prolonged, moderate exercise, the latter with higher intensity, if shorter, challenges. While very few absolute contraindications to exercising exist in these children, exercise should not be started with glycemia outside the 80–250 mg/dl range. Within this glycemic range, careful adjustments in insulin administration (reduction or infusion rate via insulin pumps, or overall reduction of dosage of multiple injections) should be combined with carbohydrate ingestion before/during exercise, based on prior, individual experience with specific exercise formats. Unfamiliar exercise should always be tackled with exceeding caution, based on known responses to other exercise formats. Finally, gaining a deep understanding of other complex exercise responses, such as the modulation of inflammatory status, which is a major determinant of the cardio-protective effects of exercise, can help determine which exercise formats and which individual metabolic conditions can lead to maximally beneficial health effects.
Shanna L. Karls, Kelli R. Snyder and Peter J. Neibert
For active individuals, plantar fasciitis (PF) is one of the most clinically diagnosed causes of heel pain. When conservative treatment fails, one of the next most commonly used treatments includes corticosteroid injections. Although PF has been identified as a degenerative condition, rather than inflammatory, corticosteroid injection is still commonly prescribed. However, the literature has not been examined to determine the effect of corticosteroid injection on PF.
Focused Clinical Question:
Are corticosteroid injections more effective than other interventions (placebo, platelet-rich plasma, and tenoxicam injections) in the short- and long-term treatment of PF?
Summary of Key Findings:
Corticosteroid injections are not more effective in the long-term treatment of PF pain than other treatments (platelet-rich plasma, tenoxicam).
Clinical Bottom Line:
The level 2 and 3 evidence shows that corticosteroids are more effective than placebo injections but are no more effective than tenoxicam injections and perhaps less effective than platelet-rich plasma treatment.
Strength of Recommendation:
Level 2 and 3 evidence suggests that corticosteroid injections are not more effective in the long-term treatment of PF than platelet-rich plasma or tenoxicam.
Tricia Majewski-Schrage and Kelli Snyder
Managing edema after trauma or injury is a primary concern for health care professionals, as it is theorized that delaying the removal of edema will increase secondary injury and result in a longer recovery period. The inflammatory process generates a series of events, starting with bleeding and ultimately leading to fluid accumulation in intercellular spaces and the formation of edema. Once edema is formed, the lymphatic system plays a tremendous role in removing excess interstitial fluid and returning the fluid to the circulatory system. Therefore, rehabilitation specialists ought to use therapies that enhance the uptake of edema via the lymphatic system to manage edema; however, the modalities commonly used are ice, compression, and elevation. Modalities such as these may be effective at preventing swelling but present limited evidence to suggest that the function of the lymphatic system is enhanced. Manual lymphatic drainage (MLD) is a manual therapy technique that assists the lymphatic system function by promoting variations in interstitial pressures by applying light pressure using different hand movements.
Focused Clinical Question:
Does MLD improve patient- and disease-oriented outcomes for patients with orthopedic injuries?