Greater basal skeletal muscle AMPKα phosphorylation in men than in women: Associations with anaerobic performance

Objectives: This study was designed to investigate the association of gender, fibre type composition, and anaerobic performance with the basal skeletal muscle signalling cascades regulating muscle phenotype. Design: Muscle biopsies were obtained from 25 men and 10 women all young and healthy. Methods. Protein phosphorylation of Thr¹⁷²AMPKα, Ser²²¹ACCβ, Thr²⁸⁶CaMKII as well as total protein abundance of PGC-1α, SIRT1, and CnA were measured by Western blot and anaerobic performance by the Wingate test. Results: Percent type I myosin heavy chain (MHC I) was lower in men (37.1?±?10.4 vs. 58.5?±?12.5, P?P?P?221ACCβ and Thr²⁸⁶CaMKII fractional phosphorylation tended to be higher in men (P?=?.1). PGC1-α and SIRT1 total protein expression was similar in men and women, whereas CnA tended to be higher in men (P?=?.1). Basal AMPKα phosphorylation was linearly related to the percentage of MHC I in men (r?=?0.56; P?Conclusion: In summary, skeletal muscle basal AMPKα phosphorylation is higher in men compared to women, with no apparent effect on anaerobic performance.     

Is salivary cortisol moderating the relationship between salivary testosterone and hand-grip strength in healthy men?

This study examined the moderating effect of cortisol (C) on the relationship between testosterone (T) and hand-grip strength (HGS) in healthy young men. Sixty-five males were monitored for salivary T, C and HGS before and 15?min after a short bout (5?×?6-s trials) of sprint cycling exercise. Sprint exercise promoted (p?<?.05) positive changes in T (6.1?±?24.9%) and HGS (3.4?±?7.5%), but a negative C response (?14.4?±?33.1%). The T and C measures did not independently predict HGS, but a significant T?×?C interaction was found in relation to these outcomes. Further testing revealed that pre-test T and HGS were negatively associated (p?<?.05), but only in men with high C levels. The exercise changes in T and HGS were also negatively related in men with low C levels (p?<?.05), but no relationship was seen in men with high C levels. In summary, complex relationships between T and HGS emerged when considering C as a moderating variable. The pre-test combination of high C and low T levels favoured absolute HGS, whereas low pre-test C levels and a smaller T change were linked to larger HGS changes. These associations suggest that, in the current format, T is not necessarily anabolic to muscle strength in healthy young men. Such complexities could also explain some of the inconsistent T relationships with physical performance in lesser trained male populations.     

Is it defensible for women to play fewer sets than men in grand slam tennis?

Lacking in the philosophy of sport is discussion of the gendered numbers of sets played in Grand Slam tennis. We argue that the practice is indefensible. It can be upheld only through false beliefs about women or repressive femininity ideals. It treats male tennis players unfairly in forcing them to play more sets because of their sex. Its ideological consequences are pernicious, since it reinforces the respective identifications of the female and male with physical limitation and heroism. Both sexes have compelling reason to reject the practice.     

Heart rate recovery after aerobic and anaerobic tests: is there an influence of anaerobic speed reserve?

The present study assessed if differences in the metabolic profile, inferred from the anaerobic speed reserve (ASR), would influence the dynamics of heart rate recovery (HRR) after two modes of exercise. Thirty-nine physical education students (14 females and 25 males) volunteered for this study. Participants carried out three separate testing sessions to assess maximal sprinting speed (MSS, 1st session), repeated sprint ability (RSA, 2nd session) and maximal aerobic speed (MAS) using the Université of Montreal Track Test (UMTT, 3rd session). ASR was defined as the difference between MSS and MAS. Heart rate was continuously registered throughout the tests and during the 5-min post-test recovery. To evaluate the influence of ASR on post-exercise, HRR comparisons between ASR-based groups [high ASR vs. low ASR] and sex groups (males vs. females) were performed. Significant differences (P < 0.05) were found between high ASR and low ASR groups of the same sex for indices of relative HRR after the RSA and UMTT. In addition, after the RSA test, males from the high ASR group had a significantly slower HRR kinetics compared with the males of the low ASR (P < 0.05) and the females of high ASR (P < 0.05); whereas females of the high ASR groups had a faster HRR kinetics compared with the females of low ASR group (P < 0.05). Our results showed that in males, post-exercise HRR could be related to the ASR, whereas in females, the influence of ASR is less clear.     

Why women see differently from the way men see? A review of sex differences in cognition and sports

The differences of learning and memory between males and females have been well documented and confirmed by both human and animal studies. The sex differences in cognition started from early stage of neuronal development and last through entire lifespan. The major biological basis of the gender-dependent cognitive activity includes two major components: sex hormone and sex-related characteristics, such as sex-determining region of the Y chromosome (SRY) protein. However, the knowledge of how much biology of sex contributes to normal cognitive function and elite athletes in various sports are still pretty limited. In this review, we will be focusing on sex differences in spatial learning and memory – especially the role of male- and female-type cognitive behaviors in sports.     

Eccentric torque–velocity and power–velocity relationships in men and women

Abstract

The purpose of this study was to investigate the eccentric torque–velocity and power–velocity relationships of the elbow flexors. Forty recreationally trained individuals (20 men, 20 women) performed maximal eccentric actions at each of five different velocities (1.04 rad · s^?1, 2.09 rad · s^?1, 3.14 rad · s^?1, 4.18 rad · s^?1, and 5.23 rad · s^?1, in random order) and maximal isometric actions on a Biodex isokinetic dynamometer. A 2×6 (sex×velocity) mixed-factor repeated-measures analysis of variance (ANOVA) was used to assess peak elbow flexor torque during the eccentric and isometric actions. There was no interaction, but there were significant main effects for sex and velocity. Pairwise comparisons demonstrated that values for men were significantly (P<0.05) higher than those for women at all speeds. Furthermore, torques for both sexes were significantly less at 3.14 rad · s^?1 (men: 103.94±28.28 N · m; women: 49.24±11.69 N · m) than at 4.18 rad · s^?1 (men: 106.39±30.23 N · m; women: 52.77±11.31 N · m) and 5.23 rad · s^?1 (men: 108.75±28.59 N · m; women: 53.3±11.67 N · m), while isometric torque was significantly less than at all other speeds (men: 98.66±28.0 N · m; women: 45.25±11.15 N · m). A 2×5 (sex×velocity) mixed-factor repeated-measures ANOVA was used to assess peak eccentric elbow flexor power. There were significant main effects for sex and velocity. Pairwise comparisons demonstrated that values for men were significantly higher than those for women at all speeds. Pairwise comparisons for velocity indicated that peak eccentric power increased across all speeds from 1.04 rad · s^?1 (men: 110.44±32.56 W; women 54.36±13.05 W) to 5.23 rad · s^?1 (men: 569.46±149.73 W; women: 279.10±61.10 W). These results demonstrate that an increase in velocity had little or no effect on eccentric elbow flexor torque, while eccentric elbow flexor power increased significantly with increases in velocity.     

Is an elevated submaximal heart rate associated with psychomotor slowness in young elite soccer players?

Abstract

The aim of the present study was to find early markers for overreaching that are applicable in sport practice. In a group of elite soccer players aged 15–18, the stress–recovery balance and reaction times before and after exercise were assessed. Overreaching was indicated by an elevated submaximal heart rate during a sport-specific field test. Submaximal changes in heart rate were prospectively monitored by means of monthly Interval Shuttle Run Tests during two competitive seasons. Out of 94 players, seven players with an elevated heart rate of at least one month could be included in the study, together with seven controls, matched for age, body composition, training and performance level. The stress–recovery balance was assessed with the Dutch version of the Recovery Stress Questionnaire (RESTQ-Sport). The soccer players with an elevated heart rate reported a disturbed stress–recovery balance (Mann–Whitney test, P<0.05). An ANOVA for repeated measures of reaction times revealed a significant main effect of time (F _1,12=13.87, P<0.01) indicating an improvement of psychomotor speed. No differences between groups were found. We conclude that soccer players with an elevated submaximal heart rate of at least one month share a disturbed stress–recovery balance, but they could not be distinguished from controls based on reaction time after strenuous exercise.     

Is starting with the feet out of the water faster in backstroke swimming?

This study aimed to determine if starting with the feet above the water (FAW) in male backstroke swimming resulted in faster start times (15-m time) than when the feet were underwater (FUW). It was hypothesised that setting higher on the wall would generate increased horizontal force and velocity, resulting in quicker starts. Twelve high-level male backstrokers performed three trials of the FAW and FUW techniques. A biomechanical swimming testing system comprising one force plate (1,000 Hz), four lateral-view (100 Hz), and five overhead (50 Hz) video cameras captured the swimmers' performance. Data for each participant's fastest trial for each technique were collated, grouped, and statistically analysed. Analysis included Wilcoxon, Spearman Rho correlation, and regression analysis. Wilcoxon results revealed a significantly faster start time for the FAW technique (p < 0.01). Peak horizontal force was significantly smaller for FAW (p = 0.02), while take-off horizontal velocity was significantly greater (p = 0.01). Regression analysis indicated take-off horizontal velocity to be a good predictor of start time for both techniques, and the horizontal displacement of the centre of mass for the FAW start.     

Do women with smaller breasts perform better in long-distance running?

Literature has established that a range of physiological, biomechanical, and training variables influence marathon performance. The influence of anthropometric characteristics has also received attention. However, despite major marathons exceeding 40,000 participants and approximately a third of these runners being female, no data exist on the influence of the breast on running performance. This cross-sectional study aimed to explore the impact of breast mass on marathon finish time. One hundred and sixty-eight of 321 female marathon runners contacted completed an on-line survey focusing on marathon performance during the 2012 London marathon. Participants were categorised as smaller (<500?g, 54%) or larger breasted (>500?g, 46%). Regression analysis identified that 24% of marathon performance variance could be explained by body mass index (BMI), but breast mass improved the model to explain 28% of performance variation. The model determined that for women with 32/34 or 36/38 underband each increase in cup size equates to a performance decrement of 4.6?min or 8.6 min, equivalent to 34.4?min difference between a woman with 36A compared to 36DD breast size. Larger breasted runners had greater BMIs, completed less marathons and had slower marathon finish times (316?±?48?min) compared to smaller breasted runners (281?±?51?min). Twenty-five per cent less larger breasted women finished in the fastest quartile. These results suggest that differences in breast mass are an important factor for female athletes and should be considered in future research in this area.     

Reduced fat oxidation during high intensity,submaximal exercise: is the availability of carnitine important?

Abstract

The increased energy demand that occurs with incremental exercise intensity is met by increases in the oxidation of both endogenous fat and carbohydrate stores up to an intensity of ~70% V˙O_2max in trained individuals. However, when exercise intensity increases beyond this workload, fat oxidation rates decline, both from a relative and absolute perspective. As endogenous glycogen use is accelerated, glycogen stores can become depleted, ultimately resulting in fatigue and the inability to maintain high intensity, submaximal exercise (>70% V˙O_2max). Despite a considerable accumulation of knowledge that has been gained over the past half century, the precise mechanism(s) regulating muscle fuel selection and underpinning the aforementioned decline in fat oxidation remain largely unclear. A greater understanding would undoubtedly lead to novel strategies to increase fat utilization and, as such, improve exercise capacity. The present review primarily addresses one of the most prominent theories to explain the phenomenon of diminished fat oxidation during high intensity, submaximal exercise; a reduced availability of muscle free carnitine for mitochondrial fat translocation. This is discussed in the light of recent work in this area taking advantage of the discovery that muscle carnitine content can be increased in vivo in humans. Furthermore, the evidence supporting the recently proposed theory that reduced muscle co-enzyme A availability to several key enzymes in the fat oxidation pathway may also exert a degree of control over muscle fuel selection during exercise is also considered. Strong correlational evidence exists that muscle free carnitine availability is likely to be a key limiting factor to fat oxidation during high intensity, submaximal exercise. However, it is concluded that further intervention studies manipulating the muscle carnitine pool in humans are required to establish a direct causal role. In addition, it is concluded that while a depletion of muscle coenzyme A availability during exercise also offers a viable mechanism for impairing fat oxidation, at present, this remains speculative.     

Macho men in a girls’ game: masculinities and the Otago men’s netball team

This article examines the experiences of seven men who play for the Otago men’s netball team (in Dunedin, New Zealand). Despite playing a sport that was initially invented as women’s basketball and in an association that has historically had a strong gay and trans* presence, they subscribe to rather hegemonic definitions of masculinity. All the players are both heterosexual and consider homosexuality incompatible with hegemonic masculinity. However, they also characterize homophobia as vulnerability and therefore a failure of masculine power. This suggests that there may be some shifts in definitions of hegemonic masculinity within this context. The traditional southern ‘hard man’ is therefore relegated to second-tier status: it is the man who tells his rugby mates that he likes netball that must ‘have a bit of bloody strength’.     

Muscle capacity and physical function in older women: What are the impacts of resistance training?

The number of older adults (individuals ≥65 years), particularly women, in our society is increasing and understanding the impact of exercise on muscle capacity (e.g., strength and power) and subsequently physical function is of utmost importance to prevent disability and maintain independence. Muscle capacity declines with age and this change negatively impacts physical function in older women. Exercise, specifically resistance training, is recommended to counteract these declines; however, the synergistic relationships between exercise, muscle capacity, and physical function are poorly understood. This review will summarize the literature regarding age-related changes in the aforementioned variables and review the research on the impact of resistance training interventions on muscle capacity and physical function in older women. Recommendations for future research in this area will be discussed.     

Is device-measured vigorous physical activity associated with health-related outcomes in children and adolescents? A systematic review and meta-analysis

ObjectiveThis study sought to analyze the prospective association between vigorous-intensity physical activity (VPA) and health-related outcomes in children and adolescents.MethodsStudies reporting associations between device-measured VPA and health-related factors in children and adolescents aged 3–18 years were identified through database searches (MEDLINE, EMBASE, and SPORTDiscus). Correlation coefficients were pooled if outcomes were reported by at least 3 studies, using DerSimonian-Laird random effects models.ResultsData from 23 studies including 13,674 participants were pooled using random effects models. Significant associations were found between VPA at baseline and overall adiposity (r = −0.09, 95% confidence interval (95%CI): –0.15 to –0.03; p = 0.002; I² = 89.8%), cardiometabolic risk score (r = –0.13, 95%CI: –0.24 to –0.02, p = 0.020; I² = 69.6%), cardiorespiratory fitness (r = 0.25, 95%CI: 0.15−0.35; p < 0.001; I² = 57.2%), and total body bone mineral density (r = 0.16, 95%CI: 0.06 to 0.25; p = 0.001; I² = 0%).ConclusionVPA seems to be negatively related to adiposity and cardiometabolic risk score and positively related to cardiorespiratory fitness and total body bone mineral density among children and adolescents at follow-up. Therefore, our findings support the need to strengthen physical activity recommendations regarding VPA due to its health benefits in children and adolescents.     

‘Power in the arm,steel in the will and courage in the breast’ – a historical approach to ideal norms and men’s dominance in Swedish club sports

From both a quantitative and qualitative perspective, research shows that men and masculinities have dominated the Swedish sports movement for a long time and that sport as a so-called ‘democratic people’s movement’ has been criticised for being a male movement. Given the self-made claims of the Swedish Sports Confederation’s fostering of inclusivity and democratisation, this study encompasses a critical and historical perspective on the inclusive and exclusive dimensions of sport. The study object is a Swedish sports club and the specific aim is to analyse the prevailing norms and ideals and how they eventually helped to reproduce men’s domination in a local sports club. Chronologically, the paper uses a historical comparative approach studying the club’s 1910s–1920s and 1970s–1980s. The research questions put are: What characterised the norms of the ideal member and collective membership in terms of gender and did these change over time? Is it possible to find specific examples of inclusion and exclusion techniques by studying the club’s photographs and stories? The main result shows subtle and explicit power techniques that reproduced (some) men’s superior position at the club level.     

‘Motivate’: the effect of a Football in the Community delivered weight loss programme on over 35-year old men and women’s cardiovascular risk factors

The purpose of this study was to examine whether an innovative, inclusive and integrated 12-week exercise, behaviour change and nutrition advice-based weight management programme could significantly improve the cardiovascular risk factors of overweight and obese men and women over the age of 35. One hundred and ninety-four men and 98 women (mean age?=?52.28?±?9.74 and 51.19?±?9.04) attending a community-based intervention delivered by Notts County Football in the Community over one year, took part in the study. Height (m), weight (kg), fitness (meters covered during a 6?min walk) and waist circumference (cm) were measured at weeks 1 and 12 as part of the intervention. Changes in body weight, waist circumference and fitness for men and women were measured by a 2-way repeated measures ANOVA, with significance set to p?<?0.05.Weight, waist circumference and fitness significantly improved over time in both men (4.96?kg, 6.29?cm, 70.22?m; p?<?0.05) and women (4.26?kg, 5.90?cm, 35.29?m; p?<?0.05). The results demonstrated that the FITC lead weight loss intervention was successful in significantly improving cardiovascular risk factors in both men and women. In particular, the weight loss reductions achieved were comparable to those seen in similar, more costly men-only programmes. This is the first study to demonstrate the efficacy of such an intervention in an inclusive, mixed gender programme and more specifically, in women.     

Is passive drag dependent on the interaction of kayak design and paddler weight in flat-water kayaking?

Abstract

Drag is one of the major factors that influences kayaking performance. To focus on the drag of the kayak’s hull shape and the paddlers’ weight per se, the passive drag (D_p) was measured on a flat-water sprint course for one paddler with added weights. D_p was measured by an electromechanical towing device using a load cell, at incremental and constant velocities from 2.78 to 5.56 m/s. Three kayaks of different sizes and shapes (Nelo® K1 Quattro-M, ML, and L) were used and the paddlers’ body weight was adjusted with weights so the total paddler weight in the kayak was 65, 75, and 85 kg. The mean D_p increased by the power function of D = kvⁿ (mean R² = .990; SD .006). The D_p went from 21.37?±?1.29 N at 2.78 m/s to 89.32?±?6.43 N at 5.56 m/s. For the two lighter weighted kayaks (65 and 75 kg), the lowest D_p was observed with different kayak sizes (M, ML, or L) depending on the target velocity. The manufacturers suggest that paddlers should select a kayak size according to their body weight to minimise drag; however, the results of this study suggest that target velocities, and thus competition distance should also be factored into kayak selection.     

Is the occurrence of the sticking region the result of diminishing potentiation in bench press?

In this study we investigated if the occurrence of the sticking region was a result of diminishing potentiation (coinciding delayed muscle activation) or the result of a mechanically poor region in which the muscles can produce less force. A regular one-repetition maximum (1RM) free-weight bench press was compared with isometric bench presses performed at 12 different positions. A lower force at the sticking region compared to the other regions in the isometric bench presses would confirm the mechanically-poor-position hypothesis. Twelve resistance-trained males (age 21.7 ± 1.3 years, mass 78 ± 5.8 kg, height 1.81 ± 0.05 m) were tested in 1RM and in isometric contractions in bench press in 12 different positions, indicated by the vertical distance between barbell and sternum, covering the whole range of motion during the concentric phase. Barbell kinematics and muscle activity were registered. In both types of executions a region of lower force output was observed, which supports the mechanically-poor-position hypothesis. Electromyographic activity of four muscles showed the same pattern in the isometric and 1RM attempts. It was concluded that diminishing effect potentiation could not explain the existence of the sticking region.     

Association of the Functional Movement Screen™ with match-injury burden in men’s community rugby union

Evidence supporting use of the Functional Movement Screen (FMS^TM) to identify athletes’ risk of injury is equivocal. Furthermore, few studies account for exposure to risk during analysis. This study investigated the association of FMS^TM performance with incidence and burden of match-injuries in adult community rugby players. 277 players performed the FMS^TM during pre-season and in-season time-loss injuries and match exposure were recorded. The associations between FMS^TM score, pain, and movement-pattern asymmetries with match-injury incidence (≥8-days time-loss/1000hours), severe match-injury incidence (>28-days time-loss/1000hours), and match-injury burden (total time-loss days/1000hours for ≥8-days match-injuries) were analysed using Poisson regression. Multivariate analysis indicated players with pain and movement-pattern asymmetry during pre-season had 2.9 times higher severe match-injury incidence (RR, 90%CI = 2.9, 0.9–9.7) and match-injury burden (RR, 90%CI = 2.9, 1.3–6.6). Players with a typically low FMS^TM score (mean – 1SD threshold) were estimated to have a 50% greater match-injury burden compared to players with a typically high FMS^TM score (mean + 1SD threshold) as match-injury burden was 10% lower per 1-unit increase in FMS^TM score. As the strongest association with injury outcome was found for players with pain and asymmetry, when implementing the FMS^TM it is advisable to prioritise these players for further assessment and subsequent treatment.     

Running intensity as determined by heart rate is the same in fast and slow runners in both the 10‐ and 21‐km races

The aims of this study were to determine (1) whether running speed is directly proportional to heart rate (HR) during field testing and during 10‐ and 21‐km races, and (2) whether running intensity, as estimated from HR measurements, differs in 10‐ and 21‐km races and between slow and fast runners at those running distances. Male runners were divided into a fast (65–80 min for 21 km; n = 8) or slow (85–110 min for 21 km; n = 8) group. They then competed in 10‐ and 21‐km races while wearing HR monitors. All subjects also ran in a field test in which HR was measured while they ran at predetermined speeds. The 10‐km time was significantly less in the fast compared with the slow group (33:15 ± 1:42 vs 40:07 ± 3:01 min:s; x ± s.d.), as was 21‐km time (74:19 ± 4:30 vs 94:13 ± 9:54 min:s) (P < 0.01). Despite the differences in running speed, the average running intensity (%HR_max) for the fast and slow groups in the 10‐km race was 90 ± 1 vs 89 ± 3% and in the 21‐km race 91 ± 1 vs 89 ± 2%, respectively. In addition, %HR_max was consistently lower in the field test at the comparative average running speeds sustained in the 10‐km (P < 0.01) and 21‐km (P < 0.001) races. Hence, factors in addition to work rate or running speed influence the HR response during competitive racing. This finding must be considered when running intensity for competitive events is prescribed on the basis of field testing performed under non‐competitive conditions in fast and slow runners.     

Where are the women in women's sports? Predictors of female athletes' interest in a coaching career

In this study, we used social cognitive career theory (Lent, Brown, & Hackett, 1994) to examine the development of female athletes' career interest in coaching and, specifically, the impact of contextual factors (female coaching role models, working hours, and perceived discrimination) on coaching self-efficacy and outcome expectations. Participants were 205 predominantly White, heterosexual female student athletes. A path analysis indicated that role models and working hours predicted coaching self-efficacy, which predicted coaching outcome expectations. Additionally, coaching self-efficacy, coaching outcome expectations, and contextual factors predicted coaching interest. Practical implications are discussed as well as suggestions for further research in this relatively unexplored area.