Acute effects of small changes in antero-posterior shoe-cleat position on physiological and biomechanical variables in road cycling.

The aim of this study was to investigate the effect of changes in cycling shoe-cleat position on pedalling biomechanics, physiological variables, and performance in road cycling. Twelve competitive road cyclists performed three pedalling trials with the cleat positioned at the first metatarsal head, 15-mm anterior and 15-mm posterior. Each trial included three sets of 5 min performed at 35%, 50%, and 65% of maximal aerobic power (MAP) followed by a 10-s sprint. Results showed no significant changes in physiological variables, pedalling kinetics, muscular activity of six lower limb muscles, sprint performance and perceived exertion. However, significant differences were found regarding joint kinematics: hip, knee, and ankle angles during both extension and flexion were reduced in the anterior cleat position. Therefore, this study suggests that cleat position does not affect sprint performance, physiological variables, pedalling kinetics, muscle activity, and perceived exertion regardless of the cycling intensity. However, joint kinematics, and particularly knee extension angle which could be related to the risk of overuse injuries, was affected by the shoe-cleat position.

Prevalence and severity of urinary incontinence among male and female competitors and recreational CrossFit® practitioners.

OBJECTIVE: This study aimed to determine the prevalence, severity and type of urinary incontinence (UI) in female and male CrossFit® practitioners. STUDY DESIGN: The study design is an online cross-sectional survey distributed to CrossFit® practitioners across all Spanish regions. The questionnaire included categorical questions related to CrossFit® practice, multiple-choice questions to determine the exercises performed during reported UI symptoms, and The International Consultation on Incontinence Questionnaire Short-Form questionnaire items. RESULTS: Five hundred seventy-one practitioners (34.0 ± 8.37 years, Body Mass Index 24.20 ± 3.34 kg/m2) met inclusion criteria and completed the survey. There were and 316 females and 255 males. Around 45 % of women and 6 % of men reported having UI (p < 0.001). The severity of UI mainly was slight (30.3 % women, 3.5 % men) and moderate (11.7 % women, 2.3 % men) (p < 0.001). Stress and urgent UI were the most prevalent types among women (36 %) and men (5 %) (p < 0.001). CONCLUSIONS: This study found that UI is relatively common among female CrossFit® practitioners, especially in repetitive jumps. The practitioners' profile (amateur/competitor) does not affect the prevalence or severity of UI. Male athletes can also experience urine leakage while performing CrossFit®, although its prevalence is much lower when compared to female practitioners.

The use of velodrome tests to evaluate aerodynamic drag in professional cyclists.

The purpose of this study was to analyse the validity, reliability and sensitivity of velodrome tests to detect small changes in aerodynamic drag in cycling. 12 professional cyclists were assessed to obtain the drag area (SCx) during wind tunnel and velodrome tests. Incremental and steady-state protocols were performed in the velodrome with a portable power meter, and 6 bicycle positions were analysed and compared that involved lowering the handlebars and advancing the pads between 2-5 cm. A significant relationship (r=0.88, p<0.001) between the SCx in the wind tunnel and velodrome tests was found (0.240 ± 0.007 and 0.237 ± 0.008 m2, respectively). The velodrome tests underestimated the SCx (0.0035 ± 0.0038 m2 and p<0.01), which decreased (p<0.001) when the bicycle speed increased (0.0013 m2 each 1 km · h(-1)). The SCx values showed high reliability during the steady-state (r=0.99, p<0.001) and incremental protocols (r=0.94, p<0.001). Small changes in the aerodynamic position affected the SCx (p<0.001), which decreased by 0.011 ± 0.007 m2 (4.6 ± 2.9%, 95% CI=2.7-6.4%). In conclusion, the validity, reliability and sensitivity of velodrome tests to detect small changes in aerodynamic drag in cycling were demonstrated. Although SCx values were not interchangeable between different studies, the velodrome tests presented advantages with respect to the wind tunnel tests.

Effect of cycling competition type on effort based on heart rate and session rating of perceived exertion.

AIM: The aim of this study was to compare the exercise intensity and competition load during Time Trial (TT), Flat (FL), Medium Mountain (MM) and High Mountain (HM) stages based heart rate (HR) and session rating of perceived exertion (RPE). METHODS: We monitored both HR and RPE of 12 professional cyclists during two consecutive 21-day cycling races (Vuelta a España) in order to analyze the exercise intensity and competition load (TRIMPHR and TRIMPRPE). RESULTS: The highest (P<0.05) mean HR was found in TT (169±2 bpm) versus those observed in FL (135±1 bpm), MM (139±3 bpm), HM (143±1 bpm). However, higher (P<0.05) session RPE were found in HM (7.3±0.2) and MM (7.0±0.3) vs. TT (5.5±0.4) and FL (4.6±0.2). TRIMPHR and TRIMPRPE increased significantly (P<0.05) in the following order: TT, FL, MM and HM. The greatest (P<0.05) TRIMPHR·km-1 and TRIMPRPE·km-1 were obtained in TT (~4 units) and HM (~12 units), respectively. We found significant (p<0.001) correlations between TRIMPHR and TRIMPRPE in TT (r=0.62), FL (r=0.74), MM (r=0.89) and HM (r=0.78). CONCLUSION: In conclusion, professional cycling is a highly demanding sport which exercise intensity and competition load varied according to the type of stages. The session RPE method is a valid estimate of internal load during different cycling stage categories.

Physical fitness levels among independent non-institutionalized Spanish elderly: the elderly EXERNET multi-center study.

BACKGROUND: Physical fitness is gaining in importance in all population groups, including elderly, but data are still scarce. The aim of this study was to report gender and age specific physical fitness levels in non-institutionalized Spanish elderly. METHODS: A representative sample of 3136 elderly (≥ 65 y), 724 men and 2412 women, from 6 Regions of Spain: Madrid, Aragón, Castilla y León, Castilla-La Mancha, Extremadura and Canarias were assessed in the elderly EXERNET multi-center study between 2008 and 2009. The authors assessed static balance, muscular strength, flexibility, agility, walking speed and cardiorespiratory fitness using eight different fitness tests: one leg balance, chair stand, arm curl, chair sit-and-reach, back scratch, 8-foot up-and-go, 30-m walk, and 6 min walk tests. RESULTS: The authors derived gender and age-specific normative values for physical fitness in the non-institutionalized Spanish elderly. The figures showed greater physical fitness in the elderly men than in women, except for the flexibility test, and a trend toward decreased physical fitness in both genders as their age increased. CONCLUSIONS: The normative values hereby provided will enable evaluation and correct interpretation of independent non-institutionalized Spanish elderly fitness status.

Physical and thermal strain of firefighters according to the firefighting tactics used to suppress wildfires.

The aim of this study was to analyse the physiological strain of firefighters, using heart rate (HR) and core temperature, during real wildfire suppression according to the type of attack performed (direct, indirect or mixed). Three intensity zones were established according to the HR corresponding to the ventilatory threshold (VT) and respiratory compensation threshold (RCT): zone 1, RCT. The exercise workload (training impulse (TRIMP)), the physiological strain index (PSI) and the cumulative heat strain index(CHSI) were calculated using the time spent in each zone, and the HR and core temperature, respectively. Significantly higher mean HR, time spent in Z2 and Z3 and TRIMP h(-1) were found in direct and mixed versus indirect attacks. The highest PSI and CHSI were observed in the direct attack. In conclusion, exercise strain and combined thermal strain, but not core temperature during wildfire suppression, are related to the type of attack performed. STATEMENT OF RELEVANCE: Our findings demonstrated that wildfire firefighting is associated with high physiological demands, which vary significantly depending on the tactics chosen for performing the task. These results should be kept in mind when planning programmes to improve wildland firefighters' physical fitness, which will allow improvement in their performance.

Workload demands in professional multi-stage cycling races of varying duration.

OBJECTIVE: To analyse and compare the workload exerted by professional cyclists in 5-day, 8-day and 21-day stage races (5-SR, 8-SR, 21-SR). METHODS: The study subjects were 30 professional cyclists competing in 10 5-SR, 5 8-SR and 5 21-SR. Heart rate (HR) was measured during the races and categorised into three intensity zones: Z1 (below the ventilatory threshold (VT)), Z2 (between VT and the respiratory compensation threshold (RCT)) and Z3 (above RCT). The training impulse (TRIMP) was calculated by multiplying the sum of the time spent in each zone by 1, 2 and 3, respectively. Monotony (average TRIMP/SD) and strain (total TRIMPxmonotony) were also calculated for each race type. RESULTS: The average time spent in Z3 during each stage was significantly (p<0.05) higher for 5-SR ( approximately 31 min) and 8-SR ( approximately 28 min) than for 21-SR ( approximately 14 min). Daily TRIMP values in 5-SR ( approximately 400) and 8-SR ( approximately 395) were also higher than in 21-SR ( approximately 370). Monotony was similar across races ( approximately 3) but strain was about three times higher for 21-SR than for 5-SR and 8-SR. CONCLUSIONS: The cyclists' effort by stage was less for 21-SR than for 5-SR and 8-SR. Competition strain and monotony accumulated during longer races influence the choice of strategies adopted by cyclists. It is likely that the intensity of each stage is modulated by total race duration, with longer races averaging the lowest daily workload.