Resistance training prescription for muscle strength and hypertrophy in healthy adults: a systematic review and Bayesian network meta-analysis.

OBJECTIVE: To determine how distinct combinations of resistance training prescription (RTx) variables (load, sets and frequency) affect muscle strength and hypertrophy. DATA SOURCES: MEDLINE, Embase, Emcare, SPORTDiscus, CINAHL, and Web of Science were searched until February 2022. ELIGIBILITY CRITERIA: Randomised trials that included healthy adults, compared at least 2 predefined conditions (non-exercise control (CTRL) and 12 RTx, differentiated by load, sets and/or weekly frequency), and reported muscle strength and/or hypertrophy were included. ANALYSES: Systematic review and Bayesian network meta-analysis methodology was used to compare RTxs and CTRL. Surface under the cumulative ranking curve values were used to rank conditions. Confidence was assessed with threshold analysis. RESULTS: The strength network included 178 studies (n=5097; women=45%). The hypertrophy network included 119 studies (n=3364; women=47%). All RTxs were superior to CTRL for muscle strength and hypertrophy. Higher-load (>80% of single repetition maximum) prescriptions maximised strength gains, and all prescriptions comparably promoted muscle hypertrophy. While the calculated effects of many prescriptions were similar, higher-load, multiset, thrice-weekly training (standardised mean difference (95% credible interval); 1.60 (1.38 to 1.82) vs CTRL) was the highest-ranked RTx for strength, and higher-load, multiset, twice-weekly training (0.66 (0.47 to 0.85) vs CTRL) was the highest-ranked RTx for hypertrophy. Threshold analysis demonstrated these results were extremely robust. CONCLUSION: All RTx promoted strength and hypertrophy compared with no exercise. The highest-ranked prescriptions for strength involved higher loads, whereas the highest-ranked prescriptions for hypertrophy included multiple sets. PROSPERO REGISTRATION NUMBER: CRD42021259663 and CRD42021258902.

Comparison of the Dynamic Postural Control During Lifting and Lowering an External Load in Low Back Pain: A Cross-Sectional Study.

OBJECTIVE: This study aimed to compare dynamic postural control between individuals with and without chronic low back pain (LBP) through load lifting and lowering. METHODS: This cross-sectional study included 52 male patients with chronic LBP (age: 33.37 ± 9.23 years) and 20 healthy male individuals (age: 31.75 ± 7.43 years). The postural control parameters were measured using a force plate system. The participants were instructed to stand barefoot (hip-width apart) on the force plate and lift a box (10% of the weight of the participants) from the waist height to overhead and then lower it from overhead to waist height. The interaction between the groups and tasks was determined using a 2-way repeated-measures analysis of variance. RESULTS: There was no significant interaction between the groups and tasks. Regardless of the groups, postural control parameters including amplitude (P = .001) and velocity (P < .001) in anterior-posterior (AP) direction, phase plane in medial-lateral (ML) direction (P = .001), phase plane in AP-ML direction (P = .001), and the mean total velocity (P < .001) were lesser during the lowering compared with lifting. The results indicated that, regardless of the tasks, the postural control parameters including velocity (P = .004) and phase plane in AP direction (P = .004), velocity in ML direction (P < .001), phase plane (AP-ML) (P = .028), and mean total velocity (P = .001) in LBP were lesser compared with the normal group. CONCLUSION: Different tasks affected postural control differently in patients with LBP and healthy individuals. Moreover, postural control was more challenged during the load-lowering than the load-lifting task. This may have been a result of a stiffening strategy. It may be that the load-lowering task might be considered as a more influential factor for the postural control strategy. These results may provide a novel understanding of selecting the rehabilitation programs for postural control disorders in patients.

Dose-response association of aerobic and muscle-strengthening physical activity with mortality: a national cohort study of 416 420 US adults.

OBJECTIVES: To investigate the dose-response association of aerobic physical activity (PA) and muscle-strengthening exercise (MSE) with all-cause mortality. METHODS: National Health Interview Survey data (1997-2014) were linked to the National Death Index through 2015, which produced a cohort of 416 420 US adults. Cox proportional-hazard models were used to estimate HRs and 95% CIs for the associations of moderate aerobic PA (MPA), vigorous aerobic PA (VPA) and MSE with mortality risk. Models controlled for age, sex, race-ethnicity, income, education, marital status, survey year, smoking status, body mass index and chronic conditions. RESULTS: Relative to those who engaged in no aerobic PA, substantial mortality risk reduction was associated with 1 hour/week of aerobic PA (HR: 0.85, 95% CI: 0.83 to 0.86) and levelled off at 3 hours/week of aerobic PA (0.73, 0.71 to 0.75). Similar results were observed for men and women and for individuals younger and older than 60 years. MSE conferred additional mortality risk reduction at 1 time/week (0.89, 0.81 to 0.97) and appeared no longer beneficial at 7 times/week (0.99, 0.94 to 1.04). CONCLUSION: The minimum effective dose of aerobic PA for significant mortality risk reduction was 1 hour/week of MPA or VPA, with additional mortality risk reduction observed up to 3 hours/week. For older adults, only small decreases in mortality risk were observed beyond this duration. Completing MSE in combination with aerobic PA conferred additional mortality risk reduction, with a minimum effective dose of 1-2 times/week.

Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases: a systematic review and meta-analysis of cohort studies.

OBJECTIVE: To quantify the associations between muscle-strengthening activities and the risk of non-communicable diseases and mortality in adults independent of aerobic activities. DESIGN: Systematic review and meta-analysis of prospective cohort studies. DATA SOURCES: MEDLINE and Embase were searched from inception to June 2021 and the reference lists of all related articles were reviewed. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Prospective cohort studies that examined the association between muscle-strengthening activities and health outcomes in adults aged ≥18 years without severe health conditions. RESULTS: Sixteen studies met the eligibility criteria. Muscle-strengthening activities were associated with a 10-17% lower risk of all-cause mortality, cardiovascular disease (CVD), total cancer, diabetes and lung cancer. No association was found between muscle-strengthening activities and the risk of some site-specific cancers (colon, kidney, bladder and pancreatic cancers). J-shaped associations with the maximum risk reduction (approximately 10-20%) at approximately 30-60 min/week of muscle-strengthening activities were found for all-cause mortality, CVD and total cancer, whereas an L-shaped association showing a large risk reduction at up to 60 min/week of muscle-strengthening activities was observed for diabetes. Combined muscle-strengthening and aerobic activities (versus none) were associated with a lower risk of all-cause, CVD and total cancer mortality. CONCLUSION: Muscle-strengthening activities were inversely associated with the risk of all-cause mortality and major non-communicable diseases including CVD, total cancer, diabetes and lung cancer; however, the influence of a higher volume of muscle-strengthening activities on all-cause mortality, CVD and total cancer is unclear when considering the observed J-shaped associations. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020219808.

The Design and Simulation of a 16-Sensors Plantar Pressure Insole Layout for Different Applications: From Sports to Clinics, a Pilot Study.

The quantification of plantar pressure distribution is widely done in the diagnosis of lower limbs deformities, gait analysis, footwear design, and sport applications. To date, a number of pressure insole layouts have been proposed, with different configurations according to their applications. The goal of this study is to assess the validity of a 16-sensors (1.5 × 1.5 cm) pressure insole to detect plantar pressure distribution during different tasks in the clinic and sport domains. The data of 39 healthy adults, acquired with a Pedar-X® system (Novel GmbH, Munich, Germany) during walking, weight lifting, and drop landing, were used to simulate the insole. The sensors were distributed by considering the location of the peak pressure on all trials: 4 on the hindfoot, 3 on the midfoot, and 9 on the forefoot. The following variables were computed with both systems and compared by estimating the Root Mean Square Error (RMSE): Peak/Mean Pressure, Ground Reaction Force (GRF), Center of Pressure (COP), the distance between COP and the origin, the Contact Area. The lowest (0.61%) and highest (82.4%) RMSE values were detected during gait on the medial-lateral COP and the GRF, respectively. This approach could be used for testing different layouts on various applications prior to production.

Symptoms of pelvic organ prolapse in women who lift heavy weights for exercise: a cross-sectional survey.

INTRODUCTION AND HYPOTHESIS: The aim of the study was to determine the prevalence of symptoms of pelvic organ prolapse (POP), defined as the sensation of a vaginal bulge, and associated risk factors in women over 18 years of age who lift light (≤15 kg), moderate (16-50 kg), and heavy (>50 kg) weights for exercise, and those who do not lift weights for exercise. METHODS: Women completed an online survey about risk factors for pelvic floor dysfunctions, physical activity history, and pelvic floor symptoms. A question about a vaginal bulge sensation from the validated Pelvic Floor Distress Inventory (PFDI-20) was used to indicate symptoms of POP. Relationships between symptoms of POP and possible risk factors were assessed through logistic regression analysis. RESULTS: Of the 3,934 survey participants, the total prevalence of POP symptoms was 14.4% (n = 566). Category of weight lifted, age, vaginal parity, history of constipation or hemorrhoids, and family history of POP were significantly associated with symptoms. Physically active women lifting weights ≤15 kg were more likely to report symptoms of pelvic organ prolapse than women lifting weights greater than 50 kg (59.7% vs 15.2%; adjusted odds ratio 2.1; 95% confidence interval 1.7-3.4). There was no relationship between POP symptoms and body mass index, forceps delivery, cesarean section, hysterectomy, or menopausal status. CONCLUSION: Physically active women who lift heavy weights for exercise do not have an increased prevalence of POP symptoms. Advice on the contribution of heavy weight lifting as part of a physical activity regime to the pathophysiology of POP requires further investigation.

Resistance training induced changes in strength and specific force at the fiber and whole muscle level: a meta-analysis.

PURPOSE: Considerable debate exists as to whether increases in strength that occur with resistance exercise are the result of increases in muscle size. Most studies have attempted to answer this question using assessments of whole muscle size and voluntary muscle strength, but examining changes at the individual muscle fiber level may also provide some insight. The purpose of this meta-analysis was to compare adaptations at the whole muscle and individual fiber level. METHODS: A meta-analysis was conducted in February, 2018 including all previously published papers and was analyzed using a random effects model. RESULTS: There were no differences (p = 0.88) when comparing hypertrophy at the whole muscle (4.6%) and individual fiber level (7.0%), but significantly larger (p < 0.001) strength gains were observed at the whole muscle level (43.3%) relative to the individual fiber (19.5%). Additionally, there was an increase in the specific tension of type 1 muscle fibers (p = 0.013), but not type 2 muscle fibers (p = 0.23) which was driven by similar increases in strength (type 1: 17.5%, type 2A: 17.7%), despite differences in muscle size (type 1: 6.7%, type 2A: 12.1%). CONCLUSION: These results support the hypothesis that the neural adaptations play a large role in increasing isotonic whole muscle strength, but also demonstrate that an improvement in specific tension of type 1 muscle fibers is present. These results would suggest that some mechanism intrinsic to the muscle fiber, and independent of muscle growth, may also be contributing to strength increases in response to resistance exercise providing an avenue for future research.

Effects of a highly intensive clean and jerk exercise on blood pressure and arterial stiffness in experienced non-professional weight lifters.

PURPOSE: Weight lifting training has gained much popularity in recent years and is frequently used in non-professional and professional settings. However, little is known about the acute effects of a highly intensive weight lifting exercise (clean and jerk) on the hemodynamic reaction. METHODS: 18 non-professional experienced weight lifters were recruited. Hemodynamic parameters were obtained and measured at baseline (T1), after warming up (T2), and after a highly intensive clean and jerk exercise (90-95% of personal best; T3). Further, 15 (T4), and 30 min (T5) post-exercise measurements were conducted. Evaluated parameters were heart rate (HR) (b/min), peripheral and central systolic and diastolic blood pressure (pSysBP, pDiaBP, cSysBP, cDiaBP) (mmHg), pulse wave velocity (PWV) (m/s), and double product (DP). RESULTS: All hemodynamic values increased from T1 up to T3 with significantly higher values measured at T3 compared to T1 and T2. Values of measured parameters at T3 were as follows: HR: 94.4 ± 15.6 b/min, pSysBP: 147.1 ± 15.9 mmHg, pDiaBP: 87.4 ± 12.2 mmHg, cSysBP: 129.3 ± 13.8 mmHg, cDiaBP: 89.9 ± 12.8 mmHg, and: 5.8 ± 0.5 m/s, DP: 14053 ± 3669. Post-exercise (T4, T5), all values returned to baseline levels. CONCLUSIONS: Results indicate that a highly intensive weight lifting exercise led to an acute increase of blood pressure and an acute stiffening of the arteries. Yet, increases were moderate and did not reach disproportionately high levels and returned to baseline levels within 15 min post-exercise. Hence, no negative acute effects of a maximum weight lifting exercise on the hemodynamic system are observed.

Effects of Acute Aerobic and Resistance Exercise on Cognitive Function and Salivary Cortisol Responses.

This study aimed to determine the comparative effectiveness of aerobic vs. resistance exercise on cognitive function. In addition, salivary cortisol responses, as an indicator of arousal-related neuroendocrine responses, were assessed as a potential mechanism underlying the effects of these 2 modes of acute exercise on cognition. Forty-two young adults were recruited and performed the Stroop task after 1 session of aerobic exercise, resistance exercise, and a sedentary condition performed on separate days. Saliva samples were collected at baseline and immediately and 30 min after treatment conditions. Acute exercise, regardless of exercise modality, improved multiple aspects of cognitive function as reflected by the Stroop task. Cortisol responses were higher after both modes of acute exercise compared with the sedentary condition and were higher at baseline and 30 min afterward compared with immediately after treatment conditions. These findings suggest that acute exercise of moderate intensity facilitates cognitive function, and, although salivary cortisol is influenced by acute exercise, levels were not related to improvements in cognition.

The systemic myokine response of decorin, interleukin-6 (IL-6) and interleukin-15 (IL-15) to an acute bout of blood flow restricted exercise.

PURPOSE: Blood flow restricted resistance exercise (BFR-RE) is an emerging hypertrophy training modality. A complete profile of its mechanisms of action has yet to be elucidated. Cytokines are universal intercellular messengers. Recent research has implicated certain cytokines (termed "myokines") in skeletal muscle hypertrophy pathways; however, little research has been conducted on the systemic myokine response to BFR-RE as potential hypertrophic biomarkers. Therefore, this project was conducted to determine any differences in the systemic myokine response between BFR-RE and control conditions. METHODS: The appearance of systemic myokines interleukin-6 (IL-6), interleukin-15 (IL-15), and decorin were measured following acute bouts of low-load resistance exercise, BFR-RE, and high-load resistance exercise in physically active young males to determine if BFR-RE modifies the exercise-induced systemic myokine response. RESULTS: No measurable levels of IL-6 were observed during the project. No significant effects were observed for IL-15. A significant time (11.91% increase pre to post exercise; p < 0.05) but no condition or condition by time effect was observed for decorin. CONCLUSION: These findings suggest that BFR-RE does not modify the systemic myokine appearance of IL-6, IL-15, or decorin when compared to control conditions.

Primary somatosensory cortex necessary for the perception of weight from other people's action: A continuous theta-burst TMS experiment.

The presence of a network of areas in the parietal and premotor cortices, which are active both during action execution and observation, suggests that we might understand the actions of other people by activating those motor programs for making similar actions. Although neurophysiological and imaging studies show an involvement of the somatosensory cortex (SI) during action observation and execution, it is unclear whether SI is essential for understanding the somatosensory aspects of observed actions. To address this issue, we used off-line transcranial magnetic continuous theta-burst stimulation (cTBS) just before a weight judgment task. Participants observed the right hand of an actor lifting a box and estimated its relative weight. In counterbalanced sessions, we delivered sham and active cTBS over the hand region of the left SI and, to test anatomical specificity, over the left motor cortex (M1) and the left superior parietal lobule (SPL). Active cTBS over SI, but not over M1 or SPL, impaired task performance relative to sham cTBS. Moreover, active cTBS delivered over SI just before participants were asked to evaluate the weight of a bouncing ball did not alter performance compared to sham cTBS. These findings indicate that SI is critical for extracting somatosensory features (heavy/light) from observed action kinematics and suggest a prominent role of SI in action understanding.

Factors associated with participation in resistance training: a systematic review.

OBJECTIVE: Regular participation in resistance training (RT) is critical to health and recommended in most international physical activity guidelines. Few people, however, participate in RT. The purpose of this review was to assess the demographic, behavioural, intrapersonal, interpersonal and environmental factors associated with participating in RT. DATA SOURCES: Eligible studies were from English peer-reviewed published articles that examined correlates or determinants of RT in adult samples. Searches were performed from August 2015 to April 2016 in six databases. RESULTS: We identified 51 independent data sets, from nine countries, primarily of moderate to high quality, and 23 factors related to participating in RT. Education, perceived health status, quality of life, affective judgements, self-efficacy, intention, self-regulation behaviours, subjective norm and programme leadership were associated with RT. CONCLUSION: Low education levels and poor health status were associated with low participation rates in RT. Intrapersonal factors including affective judgements, self-efficacy, and self-regulation behaviours, and interpersonal factors including subjective norms and programme leadership may be important for promoting RT behaviours.

Resistance training interventions across the cancer control continuum: a systematic review of the implementation of resistance training principles.

OBJECTIVES: The primary purpose of this systematic review is to examine the extant resistance training (RT) cancer research to evaluate the proportion of RT interventions that: (1) implemented key RT training principles (specificity, progression, overload) and (2) explicitly reported relevant RT prescription components (frequency, intensity, sets, reps). DESIGN: A qualitative systematic review was performed by two reviewers (CMF and PNH) who inspected the titles and abstracts to determine eligibility for this systematic review. Identified papers were obtained in full and further reviewed. Data were extracted to evaluate the application of principles of training, along with specific RT components. DATA SOURCES: Electronic databases (PubMed, EMBASE, CINAHL, Cochrane, PEDro, PsychInfo, Cancer Lit, Sport Discus, AMED, Cochrane Central Register of Controlled Trials) and reference lists of included articles from inception to May 2016. RESULTS: 37 studies were included. The principle of specificity was used appropriately in all of the studies, progression in 65% and overload in 76% of the studies. The most common exercise prescription (∼50%) implemented in the studies included in this review were 2-3 days/week, focusing on large muscle groups, 60-70% 1 repetition maximum (RM), 1-3 sets of 8-12 repetitions. CONCLUSIONS: Reporting of RT principles in an oncology setting varies greatly, with often vague or non-existent references to the principles of training and how the RT prescription was designed.

Injuries among weightlifters and powerlifters: a systematic review.

BACKGROUND: Olympic weightlifting and powerlifting are two sports that expose the body to great forces. Injury characteristics have not been systematically reviewed for these two growing sports. OBJECTIVE: The purpose of this study was to systematically review the literature regarding various definitions of injuries used, injury localisation, the prevalence and incidence of injuries and the associated risk factors for injuries in weightlifting and powerlifting. DESIGN: Systematic review. DATA SOURCES: Five databases, PubMed, MEDLINE, SPORTDiscus, Scopus and Web of Science, were searched between 9 March and 6 April 2015. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies assessing injury incidence and prevalence in Olympic weightlifting and powerlifting were included. The Quality assessment tool for observational cohort and cross-sectional studies was used to assess methodological quality. RESULTS: 9 studies were included in the review. Injury was defined fairly consistently across studies. Most studies were of low methodological quality. The spine, shoulder and the knee were the most common injury localisations in both sports. The injury incidence in weightlifting was 2.4-3.3 injuries/1000 hours of training and 1.0-4.4 injuries/1000 hours of training in powerlifting. Only one retrospective study had analysed possible risk factors. SUMMARY/CONCLUSIONS: The risk of injury in both sports were similar to other non-contact sports also requiring strength/power, but low compared to contact sports. The severity of injuries differed in the included studies. Since little has been studied regarding possible risk factors to injuries, further research is therefore warranted to explain why athletes get injured and how to prevent injuries. TRIAL REGISTRATION NUMBER: PROSPERO CRD42015014805.

Systematic Review and Meta-Analysis of the Effects of Exercise for Those With Cancer-Related Lymphedema.

OBJECTIVES: To evaluate the effects of exercise on cancer-related lymphedema and related symptoms, and to determine the need for those with lymphedema to wear compression during exercise. DATA SOURCES: CINAHL, Cochrane, EBSCOhost, MEDLINE, PubMed, ProQuest Health and Medical Complete, ProQuest Nursing and Allied Health Source, ScienceDirect, and SPORTDiscus databases were searched for trials published before January 1, 2015. STUDY SELECTION: Randomized and nonrandomized controlled trials and single-group pre-post studies published in English were included. Twenty-one (exercise) and 4 (compression and exercise) studies met inclusion criteria. DATA EXTRACTION: Data were extracted into tabular format using predefined data fields by 1 reviewer and assessed for accuracy by a second reviewer. Study quality was evaluated using the Effective Public Health Practice Project Quality Assessment Tool. DATA SYNTHESIS: Data were pooled using a random-effects model to assess the effects of acute and long-term exercise on lymphedema and lymphedema-associated symptoms, with subgroup analyses for exercise mode and intervention length. There was no effect of exercise (acute or intervention) on lymphedema or associated symptoms, with standardized mean differences from all analyses ranging between -0.2 and 0.1 (P values ≥.22). Findings from subgroup analyses for exercise mode (aerobic, resistance, mixed, other) and intervention duration (>12wk or ≤12wk) were consistent with these findings-that is, no effect on lymphedema or associated symptoms. There were too few studies evaluating the effect of compression during regular exercise to conduct a meta-analysis. CONCLUSIONS: Individuals with secondary lymphedema can safely participate in progressive, regular exercise without experiencing a worsening of lymphedema or related symptoms. However, there is insufficient evidence to support or refute the current clinical recommendation to wear compression garments during regular exercise.

Olympic weightlifting training improves vertical jump height in sportspeople: a systematic review with meta-analysis.

PURPOSE: This systematic review was conducted to evaluate the effect of Olympic weightlifting (OW) on vertical jump (VJ) height compared to a control condition, traditional resistance training and plyometric training. METHODS: Five electronic databases were searched using terms related to OW and VJ. Studies needed to include at least one OW exercise, an intervention lasting ≥6 weeks; a comparison group of control, traditional resistance training or plyometric training; and to have measured VJ height. The methodological quality of studies was assessed using the Downs and Black Checklist. Random and fixed effects meta-analyses were performed to pool the results of the included studies and generate a weighted mean effect size (ES). RESULTS: Six studies (seven articles) were included in the meta-analyses and described a total of 232 participants (175 athletes and 57 physical education students) with resistance training experience, aged 19.5±2.2 years. Three studies compared OW versus control; four studies compared OW versus traditional resistance training; and three studies compared OW versus plyometric training. Meta-analyses indicated OW improved VJ height by 7.7% (95% CI 3.4 to 5.4 cm) compared to control (ES=0.62, p=0.03) and by 5.1% (95% CI 2.2 to 3.0 cm) compared to traditional resistance training (ES=0.64 p=0.00004). Change in VJ height was not different for OW versus plyometric training. CONCLUSIONS: OW is an effective training method to improve VJ height. The similar effects observed for OW and plyometric training on VJ height suggests that either of these methods would be beneficial when devising training programmes to improve VJ height.

Effects and dose-response relationships of resistance training on physical performance in youth athletes: a systematic review and meta-analysis.

OBJECTIVES: To quantify age, sex, sport and training type-specific effects of resistance training on physical performance, and to characterise dose-response relationships of resistance training parameters that could maximise gains in physical performance in youth athletes. DESIGN: Systematic review and meta-analysis of intervention studies. DATA SOURCES: Studies were identified by systematic literature search in the databases PubMed and Web of Science (1985-2015). Weighted mean standardised mean differences (SMDwm) were calculated using random-effects models. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Only studies with an active control group were included if these investigated the effects of resistance training in youth athletes (6-18 years) and tested at least one physical performance measure. RESULTS: 43 studies met the inclusion criteria. Our analyses revealed moderate effects of resistance training on muscle strength and vertical jump performance (SMDwm 0.8-1.09), and small effects on linear sprint, agility and sport-specific performance (SMDwm 0.58-0.75). Effects were moderated by sex and resistance training type. Independently computed dose-response relationships for resistance training parameters revealed that a training period of >23 weeks, 5 sets/exercise, 6-8 repetitions/set, a training intensity of 80-89% of 1 repetition maximum (RM), and 3-4 min rest between sets were most effective to improve muscle strength (SMDwm 2.09-3.40). SUMMARY/CONCLUSIONS: Resistance training is an effective method to enhance muscle strength and jump performance in youth athletes, moderated by sex and resistance training type. Dose-response relationships for key training parameters indicate that youth coaches should primarily implement resistance training programmes with fewer repetitions and higher intensities to improve physical performance measures of youth athletes.

Citius, Altius, Fortius: beneficial effects of resistance training for young athletes: Narrative review.

The motto of the Olympic Games is Citius, Altius, Fortius which is Latin for 'Faster, Higher, Stronger'. It is a clarion call to all competitors, including the youngest, to engage in training strategies that prepare athletes to be the best in the world. Existing research indicates that various forms of resistance training can elicit performance improvements in young athletes. Stronger young athletes will be better prepared to learn complex movements, master sport tactics, and sustain the demands of training and competition. An integrative training programme grounded in resistance training and motor skill development can optimise a young athlete's potential to maximise their athletic and sporting performance, while reducing the risk of a sports-related injury. Resistance training may be especially important for modern-day young athletes who are more likely to specialise in one sport at an early age at the expense of enhancing general physical fitness and learning diversified sport skills. Structured interventions that include qualified instruction; targeted movement practice; and strength and conditioning activities that are developmentally appropriate, progressive and technique driven are needed to attain a level of athleticism that is consistent with the Olympic motto.