Kinematic determinants of early acceleration in field sport athletes

Acceleration performance is important for field sport athletes that require a high level of repeat sprint ability. Although acceleration is widely trained for, there is little evidence outlining which kinematic factors delineate between good and poor acceleration. The aim of this study was to investigate the kinematic differences between individuals with fast and slow acceleration. Twenty field sport athletes were tested for sprint ability over the first three steps of a 15m sprint. Subjects were filmed at high speed to determine a range of lower body kinematic measures. For data analysis, subjects were then divided into relatively fast (n = 10) and slow (n = 10) groups based on their horizontal velocity. Groups were then compared across kinematic measures, including stride length and frequency, to determine whether they accounted for observed differences in sprint velocity. The results showed the fast group had significantly lower (∼11-13%) left and right foot contact times (p < .05), and an increased stride frequency (∼9%), as compared to the slow group. Knee extension was also significantly different between groups (p < .05). There was no difference found in stride length. It was concluded that those subjects who are relatively fast in early acceleration achieve this through reduced ground contact times resulting in an improved stride frequency. Training for improved acceleration should be directed towards using coaching instructions and drills that specifically train such movement adaptations. ©Journal of Sports Science and Medicine (2003)

A comparison of methods used for quantifying internal training load in women soccer players

Purpose: The purpose of this study was to compare the session-RPE method for quantifying internal training load (TL) with various HR-based TL quantification methods in a variety of training modes with women soccer players. Methods: Fifteen elite women soccer players took part in the study (age: 19.3±2.0 y and VO2max: 50.8±2.7 mL·kg -1,mm-1). Session-RPE, heart rate, and duration were recorded for 735 individual training sessions and matches over a period of 16 wk. Correlation analysis was used to compare session-RPE TLs with three commonly used HR-based methods for assessing TL. Results: The mean correlation for session-RPE TL with Banister's TRIMP, LTzone TL and Edwards's TL were (r = 0.84, 0.83, and 0.85, all P < .01, respectively). Correlations for session-RPE TL and three HR-based methods separated by session type were all significant (all P < .05). The strongest correlations were reported for technical (r = 0.68 to 0.82), conditioning (r = 0.60 to 0.79), and speed sessions (r = 0.61 to 0.79). Conclusion: The session-RPE TL showed a significant correlation with all training types common to soccer. Higher correlations were found with less intermittent, aerobic-based training sessions and suggest that HR-based TLs relate better to session-RPE TLs in less intermittent training activities. These results support previous findings showing that the session-RPE TL compares favorably with HR-based methods for quantifying internal TL in a variety of soccer training activities. © 2008 Human Kinetics, Inc

The effect of habitual exercise on respiratory-muscle function in older adults

Older adults' participation in habitual exercise might be affected by alterations to respiratory mechanics such as decreased respiratory-muscle strength. This reduction can cause a decrease in efficiency of the ventilatory pump, potentially compromising exercise participation. This research examined the role of habitual exercise in respiratory-muscle function and the associated implications for exercise performance. Seventy-two healthy older adults (36 men, 64.9 ± 8.6 years, 177.2 ± 8.4 cm, 82.5 ± 11.9 kg; 36 women, 64.9 ± 9.5 years, 161.7 ± 6.4 cm, 61.6 ± 9.2 kg) undertook respiratory-function and walking-performance tests. Active men and women achieved higher scores than their inactive counterparts for all tests except spirometry, where no differences were evident. The results indicate that a significant amount of the elevated fitness level might be accounted for by increased endurance capacity of the inspiratory muscles. Inactive older individuals might be at risk for inadequate respiratory-muscle strength, so interventions should be considered

Monitoring training loads in elite tennis

Training load (TL) is influenced by both training volume and training intensity. A precise understanding of the TLs completed during training is crucial to achieve desirable training outcomes and to avoid overtraining. TL can be monitored in many different ways; however, we recommend the session-rate of perceived exertion (session-RPE) method for quantifying TL because of its low cost and because it is easy to understand and relatively simple to implement. In this report, we provide data regarding TLs collected during the 2008 Roland Garros Tournament. Our experience in tennis suggests the session-RPE method to be a valuable tool that can be used to control training and to avoid excessive TLs. We also believe that accurate monitoring of TL will enable the coach to better understand of the sports training process, ultimately leading to the improvement of performance

Small-sided games training reduces CRP, IL-6 and leptin in sedentary, middle-aged men

© 2014, Springer-Verlag Berlin Heidelberg. Purpose: Long-term physical activity is reported to improve chronic systemic inflammation, which provides protection against the ensuing development of chronic disease. Accordingly, the present study assessed changes in pro- and anti-inflammatory cytokines, aerobic capacity and body composition following 8 weeks of either small-sided games (SSG) or cycling (CYC) training compared to a sedentary control (CON) condition.Methods: Thirty-three middle-aged, sedentary men were randomized into CYC (n = 11), SSG (n = 11), or CON (n = 11) conditions. The CYC and SSG conditions trained 3 days/week for 8 weeks, whilst CON maintained habitual activity and dietary patterns. Pre- and post-intervention testing included a dual-energy X-ray absorptiometry scan, sub-maximal (80 % maximal heart rate) aerobic capacity (VO2) and fasting venous blood. Venous blood measures for pro-inflammatory markers included C-reactive protein (CRP), interleukin (IL)-6, IL-1β, tumor necrosis factor-α, and leptin; anti-inflammatory markers included IL-10, IL-1 receptor agonist, and adiponectin.Results: Both CYC and SSG increased submaximal power output and VO2 (P < 0.05), decreased total body fat-mass (TB-FM; P < 0.05), and CRP (SSG, −0.45 ± 0.42 mg L−1; P = 0.008; CYC, −0.44 ± 0.59 mg L−1; P = 0.02). Only SSG increased total body fat-free mass (TB-FFM; +1.1 ± 1.2 kg; P = 0.001) and decreased concentration of plasma IL-6 (−0.69 ± 0.62 pg mL−1; P = 0.002) and leptin (−2,212 ± 2,531 ng mL−1; P = 0.014).Conclusion: Cycling and SSG training were both effective at improving CRP, VO2 and TB-FM. Furthermore, SSG training has also shown to be an effective training approach in reducing IL-6 and leptin and increasing muscle mass within sedentary, middle-aged men

Differences in post-exercise inflammatory and glucose regulatory response between sedentary Indigenous Australian and Caucasian men completing a single bout of cycling

Objectives: This study compared the acute inflammatory and glucose responses following aerobic exercise in sedentary Indigenous Australian and Caucasian men, matched for fitness and body composition. Methods: Sedentary Indigenous (n=10) and Caucasian (n=9) Australian men who were free from chronic disease volunteered to participate. Following baseline testing, participants completed a 40 min cycling bout at ~80% maximal heart rate. Fasting venous blood was collected pre, 0, 30, 60, and 240 min post-exercise for analysis of glucose, insulin, cortisol, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-1 receptor agonist (ra), and C-reactive protein (CRP). Results: Resting TNF-α and glucose concentrations were significantly higher in the Indigenous group (P0.05). The post-exercise (0 min) increase in cortisol and glucose for the Caucasians was higher (P0.05). Conclusions: Despite being matched for fitness and body composition the Indigenous men had elevated resting TNF-α and glucose compared with the Caucasian men, which may have contributed to the suppressed post-exercise anti-inflammatory response of the Indigenous men; however, glucose normalized between groups post-exercise. As such, it is recommended for acute moderate-intensity exercise to be completed daily for long-term improvements in glucose regulation, irrespective of ancestry. Of note, results suggest it to be even more pertinent for exercise to be encouraged for Indigenous Australian men due to their elevated resting glucose levels at a younger age, when compared to the respective Caucasian group. Am. J. Hum. Biol. 26:208-214, 2014. © 2013 Wiley Periodicals, Inc

A 12-week sports-based exercise programme for inactive Indigenous Australian men improved clinical risk factors associated with type 2 diabetes mellitus

© 2014 Sports Medicine Australia. Objectives: This study assessed the effect of a 12-week sports-based exercise intervention on glucose regulation, anthropometry and inflammatory markers associated with the prevalence of type 2 diabetes mellitus (T2DM) in Indigenous Australian men. Design: Twenty-six inactive Indigenous Australian men (48.6. ± 6.6 years) were randomized into exercise (n=16) or control (n=10)conditions. Methods: Training included ~2-3 days/week for 12 weeks of sports and gym exercises in a group environment, whilst control participants maintained normal activity and dietary patterns. Pre- and post-intervention testing included: anthropometry, peak aerobic capacity, fasting blood chemistry of inflammatory cytokines, adiponectin, leptin, cholesterol, glucose, insulin and C-peptide. An oral glucose tolerance test measured glucose, insulin and C-peptide 30, 60, 90 and 120. min post 75. g glucose ingestion. Results: The exercise condition decreased insulin area under the curve (25. ± 22%), increased estimated insulin sensitivity (35. ± 62%) and decreased insulin resistance (9. ± 35%; p 0.05). The exercise condition decreased in body mass index, waist circumference and waist to hip ratio (p 0.05). Leptin decreased in the exercise group, with no changes for adiponectin (p> 0.05) or inflammatory markers (p> 0.05) in either condition. Aerobic fitness variables showed significant increases in peak oxygen consumption for the exercise condition compared to no change in control (p> 0.05). Conclusions: Findings indicate positive clinical outcomes in metabolic, anthropometric and aerobic fitness variables. This study provides evidence for sport and group-based activities leading to improved clinical risk factors associated with T2DM development in clinically obese Indigenous Australian men

The efficacy of talent selection criteria in the Australian Football League.

This study investigated the association between talent selection criteria, draft order and match performance in professional Australian Football players. Physical performance results from the Australian Football League (AFL) National Draft combine and non-performance based talent selection criteria were collated for all players drafted in the National Draft with selections 1-80 between 2003 and 2008 (n = 318). Match performance was assessed via the AFL Player Ranking metric that was provided by a commercial statistical provider (Champion Data Pty Ltd). A combination of stepwise multiple regression and linear mixed model analyses examined the influence of National Draft combine physical performance assessments and non-performance based talent selection criteria on draft order and future match performance. Earlier draft selection was associated with Under-18 all Australian team selection, height, Under-18 National Championship participation and indigenous status. The 20 m sprint and state of origin were associated with later draft selection. Under-18 all Australian team selection increased both Player Ranking/game and total Player Ranking. Under-18 all Australian team selection displays efficacy for selecting players with the potential for success

Differences in the acute inflammatory and glucose regulatory responses between small-sided games and cycling in sedentary, middle-aged men

© 2014 Sports Medicine Australia. Objectives: This study compared the acute inflammatory and glucose regulatory response within and between rugby specific small-sided games and stationary cycling in sedentary, middle-aged Caucasian men. Design: Nine middle-aged, sedentary men who were free from disease participated in 2. ×. 40 min exercise conditions (stationary cycling and small-sided games) in a randomised, cross-over design. Methods: Heart rate and Rating of Perceived Exertion were collected during each bout. Venous blood was collected at fasting, 0, 30, 60 and 240. min post-exercise for measurement of glucose, insulin, cortisol and inflammatory markers including tumour necrosis factor-α, interleukin-1β, interleukin-6, interleukin-1 receptor agonist and C-reactive protein. Results: No significant differences existed between conditions for heart rate and Rating of Perceived Exertion (p>. 0.05). Interleukin-6 was increased immediately post-exercise in both conditions (p 0.05). Results for C-reactive protein, tumour necrosis factor-α and interleukin-1β showed no significant exercise-induced changes within or between conditions (p>. 0.05). Conclusions: Both small-sided games and stationary cycling conditions were sufficient to stimulate an acute anti-inflammatory response as indicated by the post-exercise elevation of interleukin-6, interleukin-1receptor agonist and cortisol. The novel findings are that an acute bout of small-sided games bout is capable of maintaining an elevated post-exercise interleukin-6 response and lowered blood glucose concentration, compared with intensity- and duration-matched stationary cycling condition

The Effects of High-Intensity Multimodal Training in Apparently Healthy Populations: A Systematic Review.

BACKGROUND: High-intensity multimodal training (HIMT) is emerging as a popular training method that combines aerobic and resistance training throughout a single exercise session. The current literature is limited by a lack of terminology that broadly encompasses all styles of combined aerobic and resistance training. The magnitude of chronic or long-term (i.e.  ≥ 4 weeks) effects of HIMT participation on aerobic and muscular fitness also remains unclear. Additionally, one of many complex reasons for the growing popularity of HIMT may be attributed to the affective response to exercise, namely levels of enjoyment. However, this concept is not yet well understood across all styles of HIMT. A comprehensive systematic review is required to synthesise the available literature and attempt to provide an operational definition of HIMT to capture the breadth of combined training styles that exist. OBJECTIVE: The objective of this systematic review was to determine the chronic effects of HIMT participation on aerobic and muscular fitness and to compare HIMT to established concurrent training methods. Enjoyability and other adherence-related subjective responses were also examined in HIMT participants. This review critically assessed the level of evidence and feasibility of current HIMT guidelines. METHODS: A systematic literature search was conducted on PubMed, Web of Science and SPORTDiscus to identify studies up until March 2021. RESULTS: A total of 20 studies were included for review. Studies generally reported moderate to large effects on aerobic fitness and subjective responses in favour of HIMT interventions. Mixed outcomes were demonstrated in muscular fitness. These results should be treated with caution due to high risk of bias among included studies. CONCLUSIONS: Few studies have assessed the chronic effects of HIMT participation on aerobic, and musculoskeletal adaptations and subjective responses, in particular exercise enjoyment. Research conclusions are limited by heterogeneity of experimental protocols and outcome measures. Furthermore, the inability of the literature to make adequate comparisons between various styles of HIMT and other concurrent training protocols limits understandings of the efficacy of HIMT. Registration This systematic review was registered on the Open Science Framework (10.17605/OSF.IO/2RE4B; 26 March 2021)