Phys Sportsmed. 2011 Nov; 39(4): 124-30
Tjoumakaris FP, Ganley TJ, Kapur R, Kelly J, Sennett BJ, Bernstein J

Through extensive survey analysis, we investigated expert opinion in sports medicine. The study had 3 purposes: to provide clinical guidance for cases in which the correct action is not necessarily apparent, to examine expert opinion itself, and to delineate areas of future study. A total of 500 members of the American Medical Society for Sports Medicine and the American Orthopaedic Society for Sports Medicine evaluated a set of 25 statements on unresolved issues in sports medicine. The following 10 statements were deemed false: "It's okay for 12-year-old pitchers to throw curve balls; it's the pitch count that matters"; "Resistance training ('weight lifting') should be avoided until physeal closure"; "Jogging during pregnancy is to be avoided"; "At an athletic event, if sideline coverage is offered by an emergency medical technician and athletic trainer, there is little additional benefit from having a physician present"; "Contact sport athletes who sustain a second concussion should be excluded from contact sports permanently"; "The utility of pre-season medical screening is derived from the history; as such, student-athletes should complete a questionnaire, with physical examination reserved for only those with a positive relevant history"; "Femoroacetabular impingement is a myth-the designation of anatomic variation as disease"; "An AC (acromioclavicular) separation in a contact athlete should not be treated surgically if the athlete won't give up the sport; it will fail"; "Ankle taping induces weakness and atrophy of the dynamic stabilizers of the ankle"; "Only autografts should be used in ACL (anterior cruciate ligament) surgery, as allografts have an unnecessary high failure rate in clinical practice." One statement was accepted as true: "Surgery to treat anterior (patello-femoral) knee pain in a patient with normal patellar mechanics and stability is contraindicated." In short, expert opinion may be a helpful adjunct to clinical practice. Expert opinion cannot replace individual judgment and certainly does not trump the primary medical literature. Yet when better evidence is lacking, expert opinion is valuable for even the staunchest practitioner of evidence-based medicine.

Int J Sports Physiol Perform. 2011 Dec; 6(4): 509-24
Ziv G, Lidor R

The soccer goalkeeper (GK) is required to perform strenuous actions during practice sessions and actual games. One of the objectives of those professionals who work with GKs is to obtain relevant information on physical characteristics and physiological attributes of GKs, and to use it effectively when planning training programs for them. This article has three purposes: (a) to review a series of studies (n = 23) on physical characteristics, physiological attributes, and on-field performances of soccer GKs; (b) to outline a number of methodological limitations and research concerns associated with these studies; and (c) to suggest several practical recommendations for soccer coaches who work with GKs. Four main findings emerged from our review: (a) professional adult GKs usually are over 180 cm tall and have a body mass of over 77 kg; (b) studies on agility and speed produced mixed results, with some showing similar values between GKs and field players and others showing reduced performance in GKs; (c) GKs usually have higher vertical jump values when compared with players playing the various field positions; (d) GKs cover approximately 5.5 km during a game, mostly by walking and jogging. Four methodological limitations and research concerns associated with the reviewed studies were discussed, among them the lack of a longitudinal approach and the lack of on-field performance studies. Three practical recommendations are made for coaches, one of which is that coaches should adopt a careful approach when selecting testing protocols and devices for the assessment of GKs' physiological attributes.

Osteoporos Int. 2012 Jan 13;
Callréus M, McGuigan F, Ringsberg K, Akesson K

Recreational physical activity in 25-year-old women in Sweden increases bone mineral density (BMD) in the trochanter by 5.5% when combining regularity and impact. Jogging and spinning were especially beneficial for hip BMD (6.4-8.5%). Women who enjoyed physical education in school maintained their higher activity level at age 25. INTRODUCTION: The aims of this study were to evaluate the effects of recreational exercise on BMD and describe how exercise patterns change with time in a normal population of young adult women. METHODS: In a population-based study of 1,061 women, age 25 (±0.2), BMD was measured at total body (TB-BMD), femoral neck (FN-BMD), trochanter (TR-BMD), and spine (LS-BMD). Self-reported physical activity status was assessed by questionnaire. Regularity of exercise was expressed as recreational activity level (RAL) and impact load as peak strain score (PSS). A permutation (COMB-RP) was used to evaluate combined endurance and impacts on bone mass. RESULTS: More than half of the women reported exercising on a regular basis and the most common activities were running, strength training, aerobics, and spinning. Seventy percent participated in at least one activity during the year. Women with high RAL or PSS had higher BMD in the hip (2.6-3.5%) and spine (1.5-2.1%), with the greatest differences resulting from PSS (p < 0.001-0.02). Combined regularity and impact (high-COMB-RP) conferred the greatest gains in BMD (FN 4.7%, TR 5.5%, LS 3.1%; p < 0.001) despite concomitant lower body weight. Jogging and spinning were particularly beneficial for hip BMD (+6.4-8.5%). Women with high-COMB-RP scores enjoyed physical education in school more and maintained higher activity levels throughout compared to those with low scores. CONCLUSION: Self-reported recreational levels of physical activity positively influence BMD in young adult women but to maximize BMD gains, regular, high-impact exercise is required. Enjoyment of exercise contributes to regularity of exercising which has short- and long-term implications for bone health.

J Strength Cond Res. 2012 Jan 3;
Póvoas SC, Seabra AF, Ascensão AA, Magalhães J, Soares JM, Rebelo AN

This study aimed to analyze elite team handball physical and physiological demands during match play. Time-motion (N = 30) and heart rate (HR; N = 60) analyses were performed throughout ten official matches. The defined locomotor categories were: standing still, walking, jogging, fast running, sprinting, backwards movement, sideways medium-intensity movement and sideways high-intensity movement and playing actions studied were jumps, shots, stops when preceded by high-intensity activities, changes of direction and one-on-one situations. During matches the mean distances covered were 4370 ± 702.0 m. Around 80% of total time was spent standing still (43.0 ± 9.27%) and walking (35.0 ± 6.94%), and only 0.4 ± 0.31% with sprinting. The most frequent high-intensity actions were stops, changes of direction and one-on-one situations. Effective mean HR was 157 ± 18.0 bpm (82 ± 9.3% of HRmax) and total HR was 139 ± 31.9 bpm (72 ± 16.7% of HRmax). HR, time spent in high-intensity activities, frequency of stops, changes of direction, one-on-one situations and most intense periods of the game were higher during the first half than during the second half (p ≤ 0.05). The opposite was observed for the number of time-outs and the time between each change of activity (p = 0.00). Handball is an intermittent exercise that primarily utilizes aerobic metabolism, interspersed by high-intensity actions that greatly tax anaerobic metabolism. Additionally, exercise intensity decreases from the first to the second half of the match, suggesting that neuromuscular fatigue may occur during the game. The training of elite handball players should comprise exercises targeting the ability to perform specific high-intensity actions throughout the game and to rapidly recover during the less intense periods.

J Sports Med Phys Fitness. 2011 Dec; 51(4): 664-9
Zorba E, Cengiz T, Karacabey K

Increasing prevalence of obesity and related diseases especially in children and adolescent has gained more scientific attention. The present study was conducted to determine the effects of regular exercise on childhood obesity often associated with clinical conditions such as hypertension, dyslipidemia and diabetes already at a young age.The subjects were 40 obese children at 11±1 years and with Body Mass Index (BMI) of at least 30 kg/m2 who volunteered to the study and randomly classified into exercising and non-exercising control group. Physical load of the exercising group was first determined by the Karvonen protocol after which to the subjects underwent a 12-week aerobic exercise training program primary consisting of walking and jogging exercise. Blood pressure, biochemical cardiovascular risk factors and body composition were assessed before and after the exercise-training period and compared to the non-exercising control group.In the exercising group, statistically significant changes were observed in the circumference of forearm, elbow, calf, knee, waist, chest and hip, as well as skin fold thickness of chest, subscapulae, calf, abdomen, suprailiac and leg. Similarly, total cholesterol, triglyceride, LDL, VLDL and insulin levels were found to be lower and HDL levels higher than in the non-exercising control group.While treating obesity in children, a major emphasis should be directed towards increasing regular physical activity and supported with dietary interventions. By this approach the risk of other chronic diseases often associated with obesity could be minimized thereby improving the quality of life.

Gait Posture. 2011 Dec 26;
Fourchet F, Kelly L, Horobeanu C, Loepelt H, Taiar R, Millet GP

This study aimed to compare foot plantar pressure distribution while jogging and running in highly trained adolescent runners. Eleven participants performed two constant-velocity running trials either at jogging (11.2±0.9km/h) or running (17.8±1.4km/h) pace on a treadmill. Contact area (CA in cm(2)), maximum force (F(max) in N), peak pressure (PP in kPa), contact time (CT in ms), and relative load (force time integral in each individual region divided by the force time integral for the total plantar foot surface, in %) were measured in nine regions of the right foot using an in-shoe plantar pressure device. Under the whole foot, CA, F(max) and PP were lower in jogging than in running (-1.2% [p<0.05], -12.3% [p<0.001] and -15.1% [p<0.01] respectively) whereas CT was higher (+20.1%; p<0.001). Interestingly, we found an increase in relative load under the medial and central forefoot regions while jogging (+6.7% and +3.7%, respectively; [p<0.05]), while the relative load under the lesser toes (-8.4%; p<0.05) was reduced. In order to prevent overloading of the metatarsals in adolescent runners, excessive mileage at jogging pace should be avoided.

Arch Phys Med Rehabil. 2012 Jan; 93(1): 115-22
Munguía-Izquierdo D, Santalla A, Legaz-Arrese A

To evaluate the reliability and validity of a body monitoring device against measures obtained from indirect calorimetry (IC) in patients with fibromyalgia syndrome (FMS) during various incremental exercise intensities.Cross-sectional reliability and validity study.Testing was completed in a university exercise physiology laboratory.Women (N=25) with FMS, with a mean age ± SD of 48.6±8.4 years and a median symptom duration of 15 years (25th-75th percentiles, 10-23y), were recruited to the study.Not applicable.Patients walked and jogged on a treadmill at 4 intensities (50m·min(-1), 0% grade [n=25]; 83.3m·min(-1), 0% grade [n=25]; 116.7m·min(-1), 0% grade [n=21]; 116.7m·min(-1), 2.5% grade [n=13]) during 2 measurement conditions, while IC and a multiple-sensor body monitor measured energy expenditure (EE). The differences between the readings (test 1 - test 2) and the SD of the differences, intraclass correlation coefficient (ICC), 95% confidence interval (CI) for the ICC, coefficient of repeatability, intrapatient SD, standard error of mean (SEM), minimal detectable change, Wilcoxon signed-rank test, and Bland-Altman graphs were used to examine reliability. The magnitude of the associations between IC and the body monitoring device, ICC, 95% CI for the ICC, paired t tests, and Bland-Altman graphs were used to examine the validity of the body monitoring device versus the IC.Moderate to excellent test-retest reliability was found for the 4 bouts of exercise (ICC=.73-.76). The SEM and minimal detectable change were satisfactory for the 4 bouts of exercise (.54-1.18kcal·min(-1) and 1.51-3.28kcal·min(-1), respectively). The differences mean between test and retest were lower than the SEM for the 4 bouts of exercise, varying from -.17 to .14kcal·min(-1). No significant differences were found between test and retest for any bout. The Bland-Altman plots and the coefficients of repeatability indicated that the differences between repeated tests would lie within 2 SDs in 95% of the cases for the 4 bouts of exercise. Significant associations were found between the body monitoring device and IC measurements of EE for the 4 bouts of exercise (r=.87-.99). The differences for all bouts between the 2 methods were nonsignificant, except for the second bout (P<.001). The ICCs and Bland-Altman plots of EE for the 4 bouts showed high agreement (ICCs=.84-.99) and sufficient accuracy for quantifying EE during exercise in patients with FMS.The body monitoring device provided a valid and reliable estimate of EE in patients with FMS during walking on horizontal and inclined surfaces in a laboratory setting across various exercise intensities.

Diving Hyperb Med. 2011 Dec; 41(4): 183-8
Jurd KM, Thacker JC, Seddon FM, Gennser M, Loveman GA

The effect of pre-dive exercise on post-decompression venous gas emboli (VGE) remains contentious. The aim of our study was to investigate the effect of timing, intensity and mode of exercise before diving on post-decompression VGE production.Fifteen male volunteers performed three identical 100 min chamber dives to 18 metres' sea water. Two of the three dives were conducted with prior exercise at 24 or 2 h; a dive without prior exercise formed the control. Moderate-intensity impact exercise consisted of jogging on the spot for one minute followed by ten star jumps, repeated for a total of 40 min at 70% of maximum heart rate. Post-dive Doppler monitoring began within 2 min of surfacing and was carried out for at least 180 min. VGE were assessed using the Kisman-Masurel (KM) code and the Kisman Integrated Severity Score (KISS).The median peak KM grade for each condition following the dives was not significantly different. Pre-dive exercise at 2 h resulted in a significant reduction in the mean KISS compared to the control (11.3 versus 17.2, P < 0.04, Wilcoxon sign-ranked test). Moderate-intensity jogging/star jump exercise used in this series of dives resulted in significantly lower mean KISS (11.3 versus 21.8, P < 0.04) and median KM grade over 180 min (P < 0.006, Mann Whitney U test) compared to high intensity cycling exercise used previously.This study suggests that moderate-intensity impact exercise reduces VGE production when conducted 2 h prior to diving.

Zhonghua Yan Ke Za Zhi. 2011 Sep; 47(9): 854-7
Liang YB, Wu Y, Li SZ, Sun LP, Wang NL

In the 1960s, it had been observed that physical exercises could reduce the intraocular pressure (IOP) in patients with glaucoma. However, the effect of IOP reduction varied with exercise type and intensity, as well as the duration after exercise. Difference of lowering the IOP in glaucoma patients and healthy people were also observed. The mechanisms of reducing the IOP by exercise were very complicated and believed to be associated with the lower concentration of norepinephrine, the rising of colloid osmotic pressure, the co-action of nitric oxide and endothelin after exercise, and also related to the gene polymorphism of β2-adrenergic receptor. Physical exercise, such as jogging, walking and bicycle riding, could be suggested as a complimentary therapy in addition to the pharmaceutical and surgical therapies available for glaucoma patients, even though the mechanism for lowering IOP is not clear enough.

J Strength Cond Res. 2012 Jan; 26(1): 121-30
Gabbett TJ

The purpose of this study was to investigate the sprinting demands of National Rugby League (NRL) competition and characterize the sprinting patterns of different rugby league playing positions. Thirty-seven elite rugby league players (mean ± SE age: 23.6 ± 0.5 years) underwent global positioning satellite analysis during 104 NRL appearances. The majority (67.5%) of sprint efforts were across distances of <20 m. The most common sprint distance for hit-up forwards was 6-10 m (46.3%). Outside backs had a greater proportion (33.7%) of sprint efforts over distances of ≥21 m. The proportion of sprint efforts over 40 m or greater for hit-up forwards, wide running forwards, adjustables, and outside backs was 5.0, 7.4, 5.0, and 9.7%, respectively. Of the sprints performed, approximately 48.0% involved contact, approximately 58.0% were preceded by forward locomotion (forward walking, jogging, or striding), whereas over 24.0% occurred from a standing start. Hit-up forwards more commonly sprinted from a standing start, or after lateral movement, whereas forward striding activities more commonly preceded sprint efforts for the adjustables and outside backs. The majority of sprint efforts were performed without the ball (78.7 vs. 21.3%). Most sprint efforts (67.5%) were followed by a long recovery (i.e., ≥5 minutes). Outside backs had the greatest proportion (76.1%) of long duration recovery periods and the smallest proportion (1.8%) of short duration recovery periods (i.e., <60 seconds) between sprints. The results of this study demonstrate differences among rugby league playing positions for the nature of sprint efforts and the typical distances covered during these efforts. Furthermore, the activities preceding and the recovery periods after sprint efforts were different among playing positions. These findings suggest that rugby league sprint training should be tailored to meet the individual demands of specific playing positions.

J Strength Cond Res. 2011 Dec 8;
Suarez-Arrones LJ, Nuñez FJ, Portillo J, Mendez-Villanueva A

The purpose of the present study wasto examine match running performance and exercise intensity in a Rugby Sevens (7s) teamduring competitive club level matches.Time motion analyses (global position system) were performed on 7 male rugby players during 5 competitive matches in a 2-day tournament.Players covered an average distance of 1580.8±146.3 m per game (14 minutes).Over this distance, 34.8% (549.7±79.1 m) was spent standing and walking, 26.2% (414.8±105.1 m) jogging, 9.8% (154.6± 53.5 m) cruising, 15.5% (244.5±80.1 m) strinding, 5% (79.5±37.2 m) high-intensity running, and 8.7% (137.7±84.9 m) sprinting. The average maximal distance of sprints, the number of sprints, the minimum distance of sprint and the mean sprint distance over the game were: 29.5±11.7 m, 7.4±3.9 sprints, 9.1±5.7 m, and 18±7.6 m respectively. The player's work to rest ratio was 1:0.5. For over 75% of the game, players were exposed to heart rates above 80% of their maximal heart rate. There were not statistical differences between the first and second half in any of the variables analyzed. This study indicates that the physical demands of Rugby 7s are quite different from those encountered in other rugby codesand that the training regimes need to meet the increased overall running demands, the augmented high-intensity running actions, and the reduced work-to-rest ratios.

Eur J Appl Physiol. 2011 Nov 6;
Pointon M, Duffield R, Cannon J, Marino FE

This study examined the effects of cold water immersion (CWI) on recovery of neuromuscular function following simulated team-sport exercise in the heat. Ten male team-sport athletes performed two sessions of a 2 × 30-min intermittent-sprint exercise (ISE) in 32°C and 52% humidity, followed by a 20-min CWI intervention or passive recovery (CONT) in a randomized, crossover design. The ISE involved a 15-m sprint every minute separated by bouts of hard running, jogging and walking. Voluntary and evoked neuromuscular function, ratings of perceived muscle soreness (MS) and blood markers for muscle damage were measured pre- and post-exercise, immediately post-recovery, 2-h and 24-h post-recovery. Measures of core temperature (Tcore), heart rate (HR), capillary blood and perceptions of exertion, thermal strain and thirst were also recorded at the aforementioned time points. Post-exercise maximal voluntary contraction (MVC) and activation (VA) were reduced in both conditions and remained below pre-exercise values for the 24-h recovery (P < 0.05). Increased blood markers of muscle damage were observed post-exercise in both conditions and remained elevated for the 24-h recovery period (P < 0.05). Comparative to CONT, the post-recovery rate of reduction in Tcore, HR and MS was enhanced with CWI whilst increasing MVC and VA (P < 0.05). In contrast, 24-h post-recovery MVC and activation were significantly higher in CONT compared to CWI (P = 0.05). Following exercise in the heat, CWI accelerated the reduction in thermal and cardiovascular load, and improved MVC alongside increased central activation immediately and 2-h post-recovery. However, despite improved acute recovery CWI resulted in an attenuated MVC 24-h post-recovery.