The latest medical research on Sports Medicine

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about sports medicine gathered by our medical AI research bot.

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A Randomized Trial of Healthy Weight Gain in Athletic Individuals.

Medicine and Science in Sports

To evaluate the outcomes of a 10-week diet and exercise regimen designed to promote healthy weight gain with excess energy from peanut-containing or high-carbohydrate foods.

19 male and 13 female athletes were randomly assigned to receive 500 additional kcal/day above typical intake through provision of either peanut-based whole foods/snacks (PNT group) or a similar, high-carbohydrate, peanut-free snack (CHO group) along with supervised, whole-body RT (3 days/week for 60-120 minutes). Body composition was assessed by dual-energy x-ray absorptiometry at baseline and post-intervention. Results: Total body mass (TBM) increased 2.2 ± 1.3 kg with 1.5 ± 1.1 kg as LBM after week 10. The PNT group (N = 16; 27 ± 7 years; 10 men, 6 women) gained less TBM than the CHO group (N = 16; 23 ± 3 years; 9 men, 7 women) (1.6 ± 1.1 kg vs 2.7 ± 1.2 kg, respectively, P = 0.007) with no differences in LBM (1.2 ± 1.1 kg vs 1.9 ± 1.0 kg, P = 0.136).

These results suggest that the addition of 500 kcal/day from whole foods/snacks in combination with a rigorous RT program promotes a similar weight gain of ~0.22 kg/week, primarily as LBM, over 10 weeks in both male and female athletes. However, snack macronutrient content may impact the effectiveness of this regimen.

Five Weeks of Sprint Interval Training Improve Muscle Glycolytic Content and Activity But Not Time to Task Failure in Severe Intensity Exercise.

Medicine and Science in Sports

This study examined the impact of a 5 weeks sprint interval training (SIT) intervention on time to task failure (TTF) during severe intensity constant work rate (CWR) exercise, as well as in glycolytic enzymatic content and activity, and glycogen content.

Fourteen active males were randomized into either a SIT group (n = 8) composed of 15 SIT-sessions over 5 weeks, or a control group (n = 6). At pre-training period, participants performed: i) ramp incremental test to measure the cardiorespiratory function; ii) CWR cycling TTF at 150% of the power output (PO) at the respiratory compensation point (RCP-PO) with muscle biopsies at rest and immediately following task failure. After 5 weeks, the same evaluations were repeated (i.e., exercise intensities matched to current training status), and an additional cycling CWR matched to pre-training 150% RCP-PO was performed only for TTF evaluation. The content and enzymatic activity of glycogen phosphorylase (GPhos), hexokinase (HK), phosphofructokinase (PFK), and lactate dehydrogenase (LDH), as well as the glycogen content, were analyzed. Content of monocarboxylate transporter isoform 4 (MCT4) and muscle buffering capacity were also measured.

Despite improvements in total work performed at CWR post-training, no differences were observed for TTF. The GPhos, HK, PFK, and LDH content and activity, and glycogen content also improved post-training only in the SIT group. Further, the MCT4 concentrations and muscle buffering capacity was also improved only for SIT group. However, no difference in glycogen depletion was observed between groups and time.

Five weeks of SIT improved the glycolytic pathway parameters and total work performed, however, glycogen depletion was not altered during CWR severe intensity exercise, and TTF remained similar.

Plant Protein Blend Ingestion Stimulates Post-Exercise Myofibrillar Protein Synthesis Rates Equivalently to Whey in Resistance-Trained Adults.

Medicine and Science in Sports

Whey protein ingestion is typically considered an optimal dietary strategy to maximize myofibrillar protein synthesis (MyoPS) following resistance exercise. While single source plant protein ingestion is typically less effective, at least partly, due to less favorable amino acid profiles, this could theoretically be overcome by blending plant-based proteins with complementary amino acid profiles. We compared the post-exercise MyoPS response following the ingestion of a novel plant-derived protein blend with an isonitrogenous bolus of whey protein.

Ten healthy, resistance trained, young adults (male/female: 8/2; age: 26 ± 6 y; BMI: 24 ± 3 kg·m-2) received a primed continuous infusion of L-[ring-2H5]-phenylalanine and completed a bout of bilateral leg resistance exercise before ingesting 32 g protein from whey (WHEY) or a plant protein blend (BLEND; 39.5% pea, 39.5% brown rice, 21.0% canola) in a randomized, double-blind crossover fashion. Blood and muscle samples were collected at rest, and 2 and 4 h after exercise and protein ingestion, to assess plasma amino acid concentrations, and postabsorptive and post-exercise MyoPS rates.

Plasma essential amino acid availability over the 4 h postprandial post-exercise period was ~44% higher in WHEY compared with BLEND (P = 0.04). From equivalent postabsorptive values (WHEY, 0.042 ± 0.020%·h-1; BLEND, 0.043 ± 0.015%·h-1) MyoPS rates increased following exercise and protein ingestion (time effect; P < 0.001) over a 0-2 h (WHEY, 0.085 ± 0.037%·h-1; BLEND, 0.080 ± 0.037%·h-1) and 2-4 h (WHEY, 0.085 ± 0.036%·h-1; BLEND, 0.086 ± 0.034%·h-1) period, with no differences between conditions during either period or throughout the entire (0-4 h) postprandial period (time × condition interactions; all P > 0.05).

Ingestion of a novel plant-based protein blend stimulates post-exercise MyoPS to an equivalent extent as a whey protein, demonstrating the utility of plant protein blends to optimize post-exercise skeletal muscle reconditioning.

The Effects of Load, Crank Position, and Sex on the Biomechanics and Performance during an Upper Body Wingate Anaerobic Test.

Medicine and Science in Sports

The upper body Wingate Anaerobic Test (WAnT) is a 30-second maximal effort sprint against a set load (percentage of body mass). However, there is no consensus on the optimal load and no differential values for males and females, even when there are well-studied anatomical and physiological differences in muscle mass for the upper body. Our goal was to describe the effects of load, sex, and crank position on the kinetics, kinematics, and performance of the upper body WAnT.

Eighteen participants (9 females) performed three WAnTs at 3, 4, and 5% of body mass. Arm crank forces, 2D kinematics, and performance variables were recorded during each WAnT.

Our results showed an increase of ~49% effective force, ~36% peak power, ~5° neck flexion, and ~ 30° shoulder flexion from 3-5% load (p < .05). Mean power and anaerobic capacity decreased by 15%, with no changes in fatigue index (p < .05). The positions of higher force efficiency were at 12 and 6 o'clock. The least force efficiency occurred at 3 o'clock (p < .05). Sex differences showed that males produced 97% more effective force and 109% greater mean power than females, with 11.7% more force efficiency (p < .001). Males had 16° more head/neck flexion than females, and females had greater elbow joint variability with 17° more wrist extension at higher loads. Males cycled ~32% faster at 3 vs 5% load with a 65% higher angular velocity than females. Grip strength, MVIC, mass, and height positively correlated with peak and mean power (p < .001).

In conclusion, load, sex, and crank position have a significant impact on performance of the WAnT. These factors should be considered when developing and implementing an upper body WAnT.

No sign of weakness: a systematic review and meta-analysis of hip and calf muscle strength after anterior cruciate ligament injury.

Brit J Sports Med

We aimed to determine hip and lower-leg muscle strength in people after ACL injury compared with an uninjured control group (between people) and the uninjured contralateral limb (between limbs).

Primary ACL injury with mean age 18-40 years at time of injury. Studies had to measure hip and/or lower-leg muscle strength quantitatively (eg, dynamometer) and report muscle strength for the ACL-injured limb compared with: (i) an uninjured control group and/or (ii) the uninjured contralateral limb. Risk of bias was assessed according to Cochrane Collaboration domains.

Twenty-eight studies were included (n=23 measured strength ≤12 months post-ACL reconstruction). Most examined hip abduction (16 studies), hip extension (12 studies) and hip external rotation (7 studies) strength. We found no meaningful difference in muscle strength between people or between limbs for hip abduction, extension, internal rotation, flexion or ankle plantarflexion, dorsiflexion (estimates ranged from -9% to +9% of comparator). The only non-zero differences identified were in hip adduction (24% stronger on ACL limb (95% CI 8% to 42%)) and hip external rotation strength (12% deficit on ACL limb (95% CI 6% to 18%)) compared with uninjured controls at follow-ups >12 months, however both results stemmed from only two studies. Certainty of evidence was very low for all outcomes and comparisons, and drawn primarily from the first year post-ACL reconstruction.

Our results do not show widespread or substantial muscle weakness of the hip and lower-leg muscles after ACL injury, contrasting deficits of 10%-20% commonly reported for knee extensors and flexors. As it is unclear if deficits in hip and lower-leg muscle strength resolve with appropriate rehabilitation or no postinjury or postoperative weakness occurs, individualised assessment should guide training of hip and lower-leg strength following ACL injury.

CRD42020216793.

Trends in adherence to the 24-h movement guidelines among US adolescents from 2011 to 2019: Evidence from repeated cross-sectional cycles of the Youth Risk Behavior Surveillance System.

Scandinavian J Med Sci Sports

Adherence to the 24-h movement guidelines is associated with various health benefits, but given the novelty of these integrative recommendations, little is known about year-to-year trends in guideline adherence in adolescents. This study investigated trends of adherence to the 24-h movement guidelines among US adolescents.

Data from 2011 to 2019 cycles of the Youth Risk Behavior Surveillance System were used, which included 62 589 US adolescents aged 14-17 years (female: unweighted sample size = 31 876, 51%; weighted% = 50.1%). Participants self-reported their demographic information (i.e., sex, age, race/ethnicity), physical activity, screen time and sleep duration. Meeting the 24-h movement guidelines was operationalized as simultaneously engaging in 60 min or more of moderate-to-vigorous physical activity, no more than 2 h of screen time, and 8-10 h of sleep per day. Trend analysis was used to examine the secular changes in adherence to the integrated guidelines from 2011 to 2019.

Downward trends in adherence to the 24-h movement guidelines were observed among adolescents from 2011 (3.6%) to 2019 (2.6%). After stratification by sex, age, and race/ethnicity, similar downward trends in the guideline adherence were observed in females and Black/African American adolescents. The lowest prevalence of meeting the individual guidelines was for the PA guidelines (25.6%). Movement guideline adherence was consistently lowest among females, older adolescents, and those who identified as Black/African American.

Adherence to the 24-h movement guidelines has declined among US adolescents over the past decade. Interventions should prioritize an integrative approach that could increase concurrent adherence to each of the 24-h movement guideline, particularly among female, older and minority adolescents.

Groin injuries in women's premier league football in Norway: A two-season prospective cohort study describing clinical and imaging characteristics.

Scandinavian J Med Sci Sports

To describe the prevalence, incidence, and burden of groin injuries in the Norwegian women's premier football league and to describe their clinical and imaging characteristics.

During the 2020 and 2021 seasons, players in the Norwegian women's premier league reported groin injuries weekly, using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems (OSTRC-H2). We calculated weekly prevalence, incidence, and burden of groin injuries. The team physical therapists classified the player-reported injuries based on the Doha classification system. Injuries with more than 3 days' time loss or reported in 2 consecutive weeks were eligible for magnetic resonance imaging (MRI).

On average, 3.9% (95% CI: 3.4-4.4) of players reported a groin injury at any time; of which 78% caused time loss. The incidence rate was 1.6 injuries/1000 h (95% CI: 1.3-2.0) and their burden was 11 days lost/1000 h. The physical therapists examined 67 of 124 player-reported groin injuries (53%). Adductor-related injury was most common (55%) followed by iliopsoas (15%) and rectus femoris-related (12%). Pubic-related injuries caused most time loss (median: 24 days, IQR: 5-133). In this study, 42 injuries were investigated with MRI; 8 (19%) showed no changes, 6 (14%) an acute musculotendinous lesion, and 32 (76%) a nonacute finding (e.g., central symphyseal disc protrusion, tendinopathies).

The incidence rate and burden of groin injuries were high. Adductor-related injuries were most common, but pubic-related injuries caused most time loss. Most MRI examinations demonstrated nonacute findings.

Characterization of the in vivo transient responses of the femoral cartilage by means of quantitative ultrasound imaging techniques.

Scandinavian J Med Sci Sports

Quantitative ultrasound (QUS) techniques are new diagnostic tools able to identify changes in structural and material properties of the investigated tissue. For the first time, we evaluated the capability of QUS techniques in determining the in vivo transient changes in knee joint cartilage after a stressful task.

An ultrasound scanner collecting B-mode and radiofrequency data simultaneously was used to collect data from the femoral cartilage of the right knee in 15 participants. Cartilage thickness (CTK), ultrasound roughness index (URI), average magnitude ratio (AMR), and Nakagami parameters (NA) were evaluated before, immediately after and every 5 min up to 45 min a stressful task (30 min of running on a treadmill with a negative slope of 5%).

CTK was affected by time (main effect: p < 0.001). Post hoc test showed significant differences with CTK at rest, which were observed up to 30 min after the run. AMR and NA were affected by time (p < 0.01 for both variables), while URI was unaffected by it. For AMR, post hoc test showed significant differences with rest values in the first 35 min of recovery, while NA was increased compared to rest values in all time points.

Data suggest that a single running trial is not able to modify the integrity of the femoral cartilage, as reported by URI data. In vivo evaluation of QUS parameters of the femoral cartilage (NA, AMR, and URI) are able to characterize changes in cartilage properties over time.

The Dejour classification for trochlear dysplasia shows slight interobserver and substantial intraobserver reliability.

Knee Surg Sports Traumatol Arthrosc

Trochlear dysplasia is one of the main risk factors for recurrent patellar dislocation. The Dejour classification identifies four categories that can be used to classify trochlear dysplasia. The purpose of this study is to evaluate the inter- and intraobserver reliability of the Dejour classification for trochlear dysplasia. The hypothesis was that both intra- and interobserver reliability would be at least moderate.

Level I.

The mean age of patients was: 14.6 years; 60% were female and 53% had open physis. The interobserver reliability κ probabilities were 0.2 (CR), 0.13 (MRI) and 0.12 (CR and MRI). The intraobserver reliability κ probabilities were 0.45 (CR), 0.44 (MRI) and 0.65 (CR and MRI).

The Dejour classification for trochlear dysplasia has slight interobserver reliability and substantial intraobserver reliability.

Fitness Level- and Sex-Related Differences in Pulmonary Limitations to Maximal Exercise in Normoxia and Hypoxia.

Medicine and Science in Sports

Both maximal-intensity exercise and altitude exposure challenge the pulmonary system that may reach its maximal capacities. Expiratory flow limitation (EFL) and exercise-induced hypoxemia (EIH) are common in endurance-trained athletes. Furthermore, due to their smaller airways and lung size, women, independently of their fitness level, may be more prone to pulmonary limitations during maximal-intensity exercise; particularly when performed in hypoxic conditions. The objective of this study was to investigate the impact of sex and fitness level on pulmonary limitations during maximal exercise in normoxia and their consequences in acute hypoxia.

Fifty-one participants were distributed across four different groups according to sex and fitness level. Participants visited the laboratory on three occasions to perform maximal incremental cycling tests in normoxia and hypoxia (inspired oxygen fraction = 0.14) and two hypoxic chemosensitivity tests. Pulmonary function and ventilatory capacities were evaluated at each visit.

EIH was more prevalent (62.5% vs. 22.2%, p = 0.004) and EFL less common (37.5% vs. 70.4%, p = 0.019) in women than men. EIH prevalence was different (p = 0.004) between groups of trained men (41.7%), control men (6.7%), trained women (50.0%), and control women (75.0%). All EIH men but only 40% of EIH women exhibited EFL. EFL individuals had higher slope ratio (p = 0.029), higher ventilation (V̇E) (p < 0.001), larger ΔVO2max (p = 0.019) and lower hypoxia-related V̇E increase (p < 0.001).

Women reported a higher EIH prevalence than men, regardless of their fitness level, despite a lower EFL prevalence. EFL seems mainly due to the imbalance between ventilatory demands and capacities. It restricts ventilation, leading to a larger performance impairment during maximal exercise in hypoxic conditions.

Tibial spine volume is smaller in ACL-injured athletes compared to healthy athletes.

Knee Surg Sports Traumatol Arthrosc

The aim of this study was to investigate whether the whole tibial spine volume and femoral intercondylar notch volume are risk factors for anterior cruciate ligament (ACL) injury. The hypothesis was that the whole tibial spine volume and femoral notch volume would be smaller in athletes who sustained ACL injury than in athletes with no history of ACL injury.

Level Ⅲ.

Fifty-one athletes undergoing unilateral anatomical ACL reconstruction (17 female, 34 male: average age 22.0 ± 7.5) and 19 healthy collegiate athletes with no previous knee injury (eight female, 11 male: average age 20.1 ± 1.3) were included in this study. The whole tibial spine volume in the ACL-injured group (2.1 ± 0.5 cm3) was 20.7% smaller than in the ACL-intact group (2.7 ± 0.7 cm3) (p = 0.005). No differences were observed between the femoral notch volume in the ACL-injured group (9.5 ± 2.1 cm3) and the ACL-intact group (8.7 ± 2.7 cm3) (n.s.).

The main finding of this study was that the whole tibial spine volume of the ACL-injured group was smaller than the ACL-intact group. A small tibial spine volume can be added to the list of anatomical risk factors that may predispose athletes to ACL injury.

Almost 79% survival rate at 10-year follow-up for the patellofemoral joint arthroplasty: An Italian prosthetic registry study.

Knee Surg Sports Traumatol Arthrosc

The aims of the present study were (1) to evaluate the survival of patellofemoral joint (PFJ) arthroplasty in a large cohort of patients using data obtained from an Italian regional arthroplasty registry and (2) to collect clinical outcomes of a subgroup of patients, with a minimum follow-up of 4 years. The hypotheses were that PFJ arthroplasty is a procedure that had good survival and clinical outcomes, not inferior to those reported in the literature for primary total knee arthroplasty (TKA).

Level IV.

A total of 126 arthroplasties in 114 patients were included in the final analysis (mean age at surgery 60.1 ± 11.5 years old). The main causes of patellofemoral arthroplasty were primary osteoarthritis (88%) and posttraumatic arthritis (7%). The survival was 90.4 ± 30.6 and 78.8 ± 51.5 at 5 and 10 years of follow-up, respectively. At the latest follow-up, 23 implants failed (18.3%). The main cause of revision was osteoarthrosis progression (34.8%). A total of 44 patients were contacted by telephone to collect clinical outcomes: Western Ontario and McMaster Universities Osteoarthritis Index, functional Knee Society Score, Forgotten Joint Score and Oxford Knee Score. These patients reported good to excellent scores at a medium follow-up of 10.3 ± 4.7 years.

The PFJ showed good survival and clinical outcomes and could be considered a valuable option for patients affected by isolated patellofemoral osteoarthritis.