Effects of a structured midsole on spatio-temporal variables and running economy in overground running

Research to enhance running performance has led to the design of a leaf spring-structured midsole shoe (LEAF). In treadmill running, it has been shown that LEAF led to an increased running economy and increased stride length (SL) through a horizontal foot shift during stance compared to a standard foam shoe (FOAM). The purpose of this study was to analyse whether (a) these findings can also be observed in overground running and (b) relations exist between spatio-temporal variables and running economy. Ten male long-distance heel-strike runners ran at their individual 2?mmol/l blood lactate speed with LEAF and FOAM in randomized order. Kinematic data were recorded with an inertial measurement unit synchronized with 2D video. Oxygen consumption was measured using an automated metabolic gas analysis system. Blood lactate was collected after each run. The strike pattern was unaffected by LEAF. SL was increased by 0.9?±?1.1?cm (95% CI 0.2 to 1.5; p?=?.040; d_z?=?0.76), stride rate (SR) was reduced by ?0.4?±?0.3?strides/min (95% CI ?0.6 to ?0.1; p?=?.029; d_z?=?0.82) and oxygen consumption tended to be reduced by 1% (?0.4?±?0.6?ml/min/kg; 95% CI ?0.8 to 0.0; p?=?.082; d_z?=?0.62) when running with LEAF compared to FOAM. Changes in oxygen consumption in LEAF were correlated with SL (r?=?0.71; p?=?.022) and SR (r?=??0.68; p?=?.031). It can be concluded that LEAF has the potential to cause small changes in spatio-temporal variables during running. Runners increasing SL and decreasing SR in response to LEAF can achieve small improvements in running economy, which is beneficial in terms of performance.     

Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners

Abstract

The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([Vdot]O_2max), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [Vdot]O_2max (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups < 0.08). All three modes of strength training used concurrently with endurance training were effective in improving treadmill running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as improving sprinting ability at the end of a race.     

男子铁人三项运动员高原训练期跑步训练的科研监控

铁人三项虽然包括游泳、骑车和长跑三个项目,但是跑步对总成绩的影响最大,我国男子铁人三项运动员在游泳和骑车赛段中并不逊色于国外的优秀运动员,但是跑步赛段中的差距却很明显。在本次高原训练中迫切需要建立科研与训练相结合的模式,发掘优秀队员的潜能,提高单项成绩,创造我国男子铁人三项最好成绩。     

Effects of resistance training on performance in previously trained endurance runners: A systematic review

The aim of this work was to identify, synthesize and evaluate the results of randomized controlled trials examining the effects of resistance training on performance indicators in previously trained endurance runners. A database search was carried out in PubMed, Science Direct, OvidSPMedLine, Wiley, Web of Science, ProQuest and Google Scholar. In accordance with the PRISMA checklist, 18 published articles dated prior to May 2016 involving 321 endurance runners were reviewed using the PEDro scale. Resistance training led to general improvements in muscular strength, running economy, muscle power factors, and direct performance in distances between 1,500 and 10,000 m. Such improvements were not accompanied by a significant increase in body mass or signs of overtraining. However, improvements did not occur in all cases, suggesting that they might depend on the specific characteristics of the resistance training applied. Although current evidence supports the effectiveness of resistance training to improve performance in already trained endurance runners, the methodological inconsistencies identified suggest that the results should be interpreted with caution. Future studies ought to investigate the benefits of resistance training in endurance runners while considering the existence of possible differentiated effects based on the specific characteristics of the resistance training carried out.     

Effects of strength,explosive and plyometric training on energy cost of running in ultra-endurance athletes

The aim of the present study was to evaluate the effects of a 12-week home-based strength, explosive and plyometric (SEP) training on the cost of running (Cr) in well-trained ultra-marathoners and to assess the main mechanical parameters affecting changes in Cr. Twenty-five male runners (38.2?±?7.1 years; body mass index: 23.0?±?1.1?kg·m^?2; V˙O₂max: 55.4?±?4.0 mlO₂·kg^?1·min^?1) were divided into an exercise (EG?=?13) and control group (CG?=?12). Before and after a 12-week SEP training, Cr, spring-mass model parameters at four speeds (8, 10, 12, 14?km·h^?1) were calculated and maximal muscle power (MMP) of the lower limbs was measured. In EG, Cr decreased significantly (p?<?.05) at all tested running speeds (?6.4?±?6.5% at 8?km·h^?1; ?3.5?±?5.3% at 10?km·h^?1; ?4.0?±?5.5% at 12?km·h^?1; ?3.2?±?4.5% at 14?km·h^?1), contact time (t_c) increased at 8, 10 and 12?km·h^?1 by mean +4.4?±?0.1% and t_a decreased by ?25.6?±?0.1% at 8?km·h^?1 (p?<?.05). Further, inverse relationships between changes in Cr and MMP at 10 (p?=?.013; r?=??0.67) and 12?km·h^?1 (p?<?.001; r?=??0.86) were shown. Conversely, no differences were detected in the CG in any of the studied parameters. Thus, 12-week SEP training programme lower the Cr in well-trained ultra-marathoners at submaximal speeds. Increased t_c and an inverse relationship between changes in Cr and changes in MMP could be in part explain the decreased Cr. Thus, adding at least three sessions per week of SEP exercises in the normal endurance-training programme may decrease the Cr.     

Effect of two different intensity distribution training programmes on aerobic and body composition variables in ultra-endurance runners

The aim of this study was to compare the effects of two different intensity distribution training programmes (polarized (POL) and threshold (THR)) on aerobic performance, strength and body composition variables in ultra-endurance runners. Twenty recreationally trained athletes were allocated to POL (n?=?11; age: 40.6?±?9.7 years; height: 175.4?±?7?cm; weight: 73.5?±?10.8?kg; fat mass 18.4?±?6.0%; VO₂max: 55.8?±?4.9?ml/kg/min) or THR group (n?=?9; age: 36.8?±?9.2 years; height: 178.5?±?4.2?cm; weight: 75.5?±?10.4?kg; fat mass 14.9?±?5.3%; VO₂max: 57.1?±?5.2?ml/kg/min) and performed the 12 weeks training programme. Both programmes had similar total time and load but a different intensity distribution (POL?=?79.8?±?2.1% in Zone 1; 3.9?±?1.9% in Zone 2; 16.4?±?1.5% in Zone 3; THR?=?67.2?±?4.6% in Zone 1; 33.8?±?4.6% in Zone 2; 0% in Zone 3). Body composition, isokinetic strength and aerobic running performance were measured before and after each programme. Both groups decreased fat mass after training (POL= Δ–11.2%; p?=?.017; ES?=?0.32; THR= Δ–18.8%; p?p?=?0.003; ES?=?0.71) and 12?km/h (Δ–4.5%; p?=?.026; ES?=?0.73) and running time to exhaustion (Δ2.4%; p?=?.011; ES?=?0.33). No changes were observed in strength and no significant differences were observed between the group in any variable. Compared with THR distribution, 12 weeks of POL training efficiently improves aerobic performance in recreational ultra-endurance runners.     

Effects of plyometric training on maximal-intensity exercise and endurance in male and female soccer players

In a randomised controlled trial design, effects of 6 weeks of plyometric training on maximal-intensity exercise and endurance performance were compared in male and female soccer players. Young (age 21.1 ± 2.7 years) players with similar training load and competitive background were assigned to training (women, n = 19; men, n = 21) and control (women, n = 19; men, n = 21) groups. Players were evaluated for lower- and upper-body maximal-intensity exercise, 30 m sprint, change of direction speed and endurance performance before and after 6 weeks of training. After intervention, the control groups did not change, whereas both training groups improved jumps (effect size (ES) = 0.35–1.76), throwing (ES = 0.62–0.78), sprint (ES = 0.86–1.44), change of direction speed (ES = 0.46–0.85) and endurance performance (ES = 0.42–0.62). There were no differences in performance improvements between the plyometric training groups. Both plyometric groups improved more in all performance tests than the controls. The results suggest that adaptations to plyometric training do not differ between men and women.     

Effects of concurrent training on interleukin-6, tumour necrosis factor-alpha and C-reactive protein in middle-aged men

Abstract

The purpose of this study was to evaluate the effects of moderate- to high-intensity resistance and concurrent training on inflammatory biomarkers and functional capacity in sedentary middle-aged healthy men. Participants were selected on a random basis for resistance training (n = 12), concurrent training (n = 11) and a control group (n = 13). They performed three weekly sessions for 16 weeks (resistance training: 10 exercises with 3 × 8–10 repetition maximum; concurrent training: 6 exercises with 3 × 8–10 repetition maximum, followed by 30 minutes of walking or running at 55–85% [Vdot]O_2peak). Maximal strength was tested in bench press and leg press. The peak oxygen uptake ([Vdot]O_2peak) was measured by an incremental exercise test. Tumour necrosis factor-α, interleukin-6 and C-reactive protein were determined. The upper- and lower-body maximal strength increase for both resistance (+42.52%; +20.9%, respectively) and concurrent training (+28.35%; +21.5%, respectively) groups (P = 0.0001).[Vdot]O_2peak increased in concurrent training when comparing pre- and post-training (P = 0.0001; +15.6%). No differences were found in tumour necrosis factor-α and interleukin-6 for both groups after the exercise. C-reactive protein increased in resistance training (P = 0.004). These findings demonstrated that 16 weeks of moderate- to high-intensity training could improve functional capacity, but did not decrease inflammatory biomarkers in middle-aged men.     

Effects of intermittent sprint and plyometric training on endurance running performance

PurposeThe purpose of this study was to compare the effects of intermittent sprint training and plyometric training on endurance running performance.MethodsFourteen moderately trained male endurance runners were allocated into either the intermittent sprint training group (n = 7) or the plyometric training group (n = 7). The preliminary tests required subjects to perform a treadmill graded exercise test, a countermovement jump test for peak power measurement, and a 10-km time trial. Training included 12 sessions of either intermittent sprint or plyometric training carried out twice per week. On completion of the intervention, post-tests were conducted.ResultsBoth groups showed significant reduction in weekly training mileage from pre-intervention during the intervention period. There were significant improvements in the 10-km time trial performance and peak power. There was also significant improvement in relative peak power for both groups. The 10-km time trial performance and relative peak power showed a moderate inverse correlation.ConclusionThese findings showed that both intermittent sprint and plyometric training resulted in improved 10-km running performance despite reduction in training mileage. The improvement in running performance was accompanied by an improvement in peak power and showed an inverse relationship with relative peak power.     

The validity of endurance running performance on the Curve 3TM non-motorised treadmill

This study aimed to test the validity of a non-motorised treadmill (NMT) for the measurement of self-paced overground endurance running performance. Ten male runners performed randomised 5-km running time trials on a NMT and an outdoor athletics track. A range of physiological and perceptual responses was measured, and foot strike was classified subjectively. Performance time was strongly correlated (r = 0.82, ICC = 0.86) between running modes, despite running time being significantly longer on the NMT (1264 ± 124 s vs. 1536 ± 130 s for overground and NMT, respectively; P < 0.001). End blood lactate concentration and rating of perceived exertion were significantly higher on the NMT compared to overground. Integrated electromyography was significantly lower on the NMT for three muscles (P < 0.05), and mean stride rate was also significantly lower on the NMT (P = 0.04). Cardiorespiratory responses of heart rate, oxygen uptake and expired air volume demonstrated strong correlations (r = 0.68–0.96, ICC = 0.75–0.97) and no statistical differences (P > 0.05). Runners were consistently slower on the NMT, and as such it should not be used to measure performance over a specific distance. However, the strong correlations suggest that superior overground performance was reflected in relative terms on the NMT, and therefore, it is a valid tool for the assessment of endurance running performance in the laboratory.     

10 weeks of heavy strength training improves performance-related measurements in elite cyclists

ABSTRACT

Elite cyclists have often a limited period of time available during their short preparation phase to focus on development of maximal strength; therefore, the purpose of the present study was to investigate the effect of 10-week heavy strength training on lean lower-body mass, leg strength, determinants of cycling performance and cycling performance in elite cyclists. Twelve cyclists performed heavy strength training and normal endurance training (E&S) while 8 other cyclists performed normal endurance training only (E). Following the intervention period E&S had a larger increase in maximal isometric half squat, mean power output during a 30-s Wingate sprint (P < 0.05) and a tendency towards larger improvement in power output at 4 mmol ? L^?1 [la^?] than E (P = 0.068). There were no significant difference between E&S and E in changes in 40-min all-out trial (4 ± 6% vs. ?1 ± 6%, respectively, P = 0.13). These beneficial effects may encourage elite cyclists to perform heavy strength training and the short period of only 10 weeks should make it executable even in the compressed training and competition schedule of elite cyclists.     

力量耐力训练对大鼠骨骼肌超微结构和酶的影响

研究旨在观察力量耐力训练对大鼠骨骼肌的超微结构以及氧化酶与无氧酶含量的影响,结果发现:受6 w力量耐力训练的影响,Gn、LDH、SDH以及ATPase含量明显升高,肌纤维排列整齐、线粒体体积增大,数量增多,线粒体嵴致密,表明力量耐力训练可以有效的提高机体的有氧和无氧代谢能力。     

The physiological effects of concurrent strength and endurance training sequence: A systematic review and meta-analysis

We conducted a systematic literature review and meta-analysis to assess the chronic effects of the sequence of concurrent strength and endurance training on selected important physiological and performance parameters, namely lower body 1 repetition maximum (1RM) and maximal aerobic capacity (VO₂max/peak). Based on predetermined eligibility criteria, chronic effect trials, comparing strength-endurance (SE) with endurance-strength (ES) training sequence in the same session were included. Data on effect sizes, sample size and SD as well other related study characteristics were extracted. The effect sizes were pooled using, Fixed or Random effect models as per level of heterogeneity between studies and a further sensitivity analyses was carried out using Inverse Variance Heterogeneity (IVHet) models to adjust for potential bias due to heterogeneity. Lower body 1RM was significantly higher when strength training preceded endurance with a pooled mean change of 3.96 kg (95%CI: 0.81 to 7.10 kg). However, the training sequence had no impact on aerobic capacity with a pooled mean difference of 0.39 ml.kg.min^?1 (95%CI: ?1.03 to 1.81 ml.kg.min^?1). Sequencing strength training prior to endurance in concurrent training appears to be beneficial for lower body strength adaptations, while the improvement of aerobic capacity is not affected by training order.     

The effects of maturation on jumping ability and sprint adaptations to plyometric training in youth soccer players

The aim of this study was to investigate the effects of maturation on power and sprint performance adaptations following 6 weeks of plyometric training in youth soccer players during pre-season. Sixty male soccer players were categorized into 3 maturity groups (Pre, Mid and Post peak height velocity [PHV]) and then randomly assigned to plyometric group and control group. Vertical jump, standing long jump, and 20-m sprint (with and without ball) tests were collected before- and after-intervention. After the intervention, the Pre, Mid and Post-PHV groups showed significant (P ≤ 0.05) and small to moderate effect size (ES) improvement in vertical jump (ES = 0.48; 0.57; 0.73), peak power output (E = 0.60; 0.64; 0.76), standing long jump (ES = 0.62; 0.65; 0.7), 20-m sprint (ES = ?0.58; ?0.66), and 20-m sprint with ball (ES = ?0.44; ?0.8; ?0.55) performances. The Post-PHV soccer players indicated greater gains than Pre-PHV in vertical jump and sprint performance after training (P ≤ 0.05). Short-term plyometric training had positive effects on sprinting and jumping-power which are important determinants of match-winning actions in soccer. These results indicate that a sixty foot contact, twice per week program, seems effective in improving power and sprint performance in youth soccer players.     

两种训练方式对男大学生STI的影响

为了探讨同属有氧训练的短期耐力和力量性耐力训练对男大学生STI的影响．分别在训练前、训练6周和训练8周后测试了20名男大学生的S11。结果发现：耐力训练6周后LVET、QS2就有显著性延长．而力量性耐力训练8周后LVET、QS2才有显著性延长。这提示：短期耐力训练和力量性耐力训练都能延长LVET和QS2，但存在一个不同的训练时间阈值。     

The compatibility of concurrent high intensity interval training and resistance training for muscular strength and hypertrophy: a systematic review and meta-analysis

The purpose of this systematic review and meta-analysis is to assess the effect of concurrent high intensity interval training (HIIT) and resistance training (RT) on strength and hypertrophy. Five electronic databases were searched using terms related to HIIT, RT, and concurrent training. Effect size (ES), calculated as standardised differences in the means, were used to examine the effect of concurrent HIIT and RT compared to RT alone on muscle strength and hypertrophy. Sub-analyses were performed to assess region-specific strength and hypertrophy, HIIT modality (cycling versus running), and inter-modal rest responses. Compared to RT alone, concurrent HIIT and RT led to similar changes in muscle hypertrophy and upper body strength. Concurrent HIIT and RT resulted in a lower increase in lower body strength compared to RT alone (ES = ?0.248, p = 0.049). Sub analyses showed a trend for lower body strength to be negatively affected by cycling HIIT (ES = ?0.377, p = 0.074) and not running (ES = ?0.176, p = 0.261). Data suggests concurrent HIIT and RT does not negatively impact hypertrophy or upper body strength, and that any possible negative effect on lower body strength may be ameliorated by incorporating running based HIIT and longer inter-modal rest periods.     

Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners

The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([V·]O(?max)), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [V·]O(?max) (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups < 0.08). All three modes of strength training used concurrently with endurance training were effective in improving treadmill running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as improving sprinting ability at the end of a race.     

掌握生理现象的规律指导体育教学与训练

论述了在体育教学和运动训练中如何运用"条件反射"、"超量恢复"、"间歇训练"、"极点"等生理现象的规律,同时论证了正确认识这些规律对提高体育教学、运动训练质量及运动技术水平能起到较大的促进作用.     

Effects of a verbal and visual feedback system on running technique,perceived exertion and running economy in female novice runners

The purpose of this study was to determine the effects of a verbal and visual feedback system on running technique, ratings of perceived exertion (RPE), and running economy. Twenty‐two female novice runners were randomly assigned to experimental (n = 11) and control (n = 11) groups. The experimental subjects received verbal and visual feedback concerning their running technique prior to and during each training run. Training involved 15 20‐min treadmill running sessions over a 5‐week period. The control group adhered to the same training routine but did not receive feedback concerning their running technique. High‐speed (100 Hz) photography was used to collect biomechanical data. A submaximal oxygen consumption test and Borg's RPE scale were used to collect data concerning running economy and perceived exertion, respectively. Statistical analysis using ANCOVA revealed that the proposed feedback system had a significant (P < 0.01) effect on the experimental group's running technique by affecting the following desired changes relative to the control group: greater relative stride lengths, shorter support time, greater ankle dorsiflexion during support and greater knee flexion during support and non‐support. There were no significant differences between the groups in submaximal VO₂ or RPE. The results of this study suggest that verbal and visual feedback are effective means of eliciting modifications in running style in female novice runners. The link between modifications in running style and improvements in running economy and perceived exertion remains unclear.