Effect of the Fran CrossFit Workout on Oxygen Uptake Kinetics, Energetics, and Postexercise Muscle Function in Trained CrossFitters.

PURPOSE: Fran is one of the most popular CrossFit benchmark workouts used to control CrossFitters' improvements. Detailed physiological characterization of Fran is needed for a more specific evaluation of CrossFitters' training performance improvements. The aim of the study was to analyze the oxygen uptake (V˙O2) kinetics and characterize the energy system contributions and the degree of postexercise fatigue of the unbroken Fran. METHODS: Twenty trained CrossFitters performed Fran at maximal exertion. V˙O2 and heart-rate kinetics were assessed at baseline and during and post-Fran. Blood lactate and glucose concentrations and muscular fatigue were measured at baseline and in the recovery period. RESULTS: A marked increase in V˙O2 kinetics was observed at the beginning of Fran, remaining elevated until the end (V˙O2peak: 49.2 [3.7] mL·kg-1·min-1, V˙O2 amplitude: 35.8 [5.2] mL·kg-1·min-1, time delay: 4.7 [2.5] s and time constant: 23.7 [11.1] s; mean [SD]). Aerobic, anaerobic lactic, and alactic pathways accounted for 62% (4%), 26% (4%), and 12% (2%) of energy contribution. Reduction in muscle function in jumping ability (jump height: 8% [6%], peak force: 6% [4%], and maximum velocity: 4% [2%]) and plank prone test (46% [20%]) was observed in the recovery period. CONCLUSIONS: The Fran unbroken workout is a high-intensity effort associated with an elevated metabolic response. This pattern of energy response highlights the primary contribution of aerobic energy metabolism, even during short and very intense CrossFit workouts, and that recovery can take >24 hours due to cumulative fatigue.

Swimming sprint performance depends on upper/lower limbs strength and swimmers level.

Swimming performance is likely influenced by strength, but differences between butterfly, backstroke, breaststroke and front crawl, as well as between novice and expert swimmers, are unclear. We have examined the associations between sprint performances, upper and lower limb strength, and anthropometric characteristics in 14 (six males and eight females) non-elite and 16 (nine males and seven females) elite-level swimmers. After an anthropometric characterisation, participants performed four 25 m maximal swims (one per technique) with 10 min intervals, right and left shoulder flexion/extension isokinetic testing at 90 and 300º/s angular velocities and three countermovement jumps. Pearson correlation analysis showed that sprint times were moderate-largely negatively correlated with upper and lower limb strength and power (r ± 95%CI = 0.39 ± 0.26-0.77 ± 0.13, p < 0.05). Elite swimmers higher strength levels were associated with longer stroke length in butterfly and front crawl, and with higher stroke rate in backstroke and breaststroke (r ± 95%CI = 0.37 ± 0.32-0.68 ± 0.21; p < 0.05). Butterfly, backstroke and front crawl sprint times were moderate-largely negatively related with arm span (r ± 95%CI = 0.37 ± 0.26, 0.39 ± 0.25 and 0.69 ± 0.17, p < 0.05). The predictive model indicated that higher dry-land strength values distinguished elite from non-elite swimmers (r2 = 0.67-0.81; p < 0.001). This association was not observed per performance level and per sex, confirming that sprint swimming performance levels can be differentiated by dry-land strength testing.

Swimming With the COSMED AquaTrainer and K5 Wearable Metabolic System in Breath-by-Breath Mode: Accuracy, Precision, and Repeatability.

PURPOSE: To compare ventilatory and cardiorespiratory responses between the COSMED AquaTrainer coupled with the K4b2 and K5 wearable metabolic systems in breath-by-breath mode over a wide range of swimming speeds. METHODS: Seventeen well-trained master swimmers performed 2 front-crawl 7 × 200-m incremental intermittent protocols (increments of 0.05 m·s-1 and 30-s rest intervals, with a visual pacer) with AquaTrainer coupled with either K4b2 or K5. RESULTS: Post hoc tests showed that swimming speed was similar (mean diff.: -0.01 to 0.01 m·s-1; P = .73-.97), repeatable (intraclass correlation coefficient: .88-.99; P < .001), highly accurate, and precise (agreement; bias: -0.01 to 0.01 m·s-1; limits: -0.1 to 0.1 m·s-1) between all conditions. Ventilatory and cardiorespiratory responses were highly comparable between all conditions, despite a "small" effect size for fraction of expired carbon dioxide at the sixth 200-m step (0.5%; ηp2=.12; P = .04) and carbon dioxide production at the fifth, sixth, and seventh 200-m steps (0.3-0.5 L·min-1; ηp2=.11-.17; P = .01-.05). We also observed high accuracy, which was greater for tidal volume (0.0-0.1 L), minute ventilation (-3.7 to 5.1 L·min-1), respiratory frequency (bias: -2.1 to 1.9 breaths·min-1), and oxygen uptake (0.0-0.2 L·min-1). Bland-Altman plots showed that the distribution inside the limits of agreement and their respective 95% CIs were consistent for all ventilatory and cardiorespiratory data. The repeatability (intraclass correlation coefficient) of tidal volume (.93-.97), minute ventilation (.82-.97), respiratory frequency (.68-.96), fraction of expired carbon dioxide (.85-.95), carbon dioxide production (.77-.95), fraction of expired oxygen (.78-.92), and oxygen uptake (.94-.98) data ranged from moderate to excellent (P < .001-.05). CONCLUSIONS: Swimming with the AquaTrainer coupled with K5 (breath-by-breath mode) yields accurate, precise, and repeatable ventilatory and cardiorespiratory responses when compared with K4b2 (previous gold standard). Swimming support staff, exercise and health professionals, and researchers can now relate differences between physiological capacities measured with the AquaTrainer while coupled with either of these 2 devices.

Physical Fitness Profile of High-Level Female Portuguese Handball Players.

We characterized the physical and physiological profiles of high-level female Portuguese handball players and examined the relationships between their anthropometric characteristics, general motor performance and cardiopulmonary fitness. Twenty-four high-level female handball players with an average age of 23.6 ± 5.5 years, height of 173.6 ± 5.1 cm and body mass of 72.6 ± 9.1 kg volunteered to participate. A Pearson correlation test was used to assess the relationship between variables. Direct relationships were observed between the players' height and arm span (r = 0.741), as well as between their squat jump and countermovement jump performances with regard to body mass (r = 0.448 and 0.496, respectively). The 9 m jump shot has a large relationship with the 7 m standing throw (r = 0.786) and between left hand dynamometry and body mass index (r = 0.595). The 30 m sprint has a relationship with the 7 m standing throw (r = -0.526) and the 9 m jump throw (r = -0.551). Oxygen uptake has a relationship with the players' height (r = -0.482) and time limit (r = 0.513), while the fitness index has a relation to the players' height (r = -0.488) and arm span (r = -0.422). Our results should be considered when using physical testing to plan optimal physical training regimens in elite team handball.

Acute ventilatory responses to swimming at increasing intensities.

Background: Physical exercise is a source of stress to the human body, triggering different ventilatory responses through different regulatory mechanisms and the aquatic environment imposes several restrictions to the swimmer, particularly regarding the restricted ventilation. Thus, we aimed to assess the acute ventilatory responses and to characterize the adopted breathing patterns when swimming front crawl at increasing intensity domains. Methods: Eighteen well-trained swimmers performed 7 × 200 m front crawl (0.05 m∙s-1 velocity increments) and a maximal 100 m (30 s rest intervals). Pulmonary gas exchange and ventilation were continuously measured (breath-by-breath) and capillary blood samples for lactate concentration ([La-]) analysis were collected at rest, during intervals and at the end of the protocol, allowing the identification of the low, moderate, heavy, severe and extreme intensity domains. Results: With the swimming velocity rise, respiratory frequency (f R), [La-] and stroke rate (SR) increased ([29.1-49.7] breaths∙min-1, [2.7-11.4] mmol∙L-1, [26.23-40.85] cycles; respectively) and stroke length (SL) decreased ([2.43-2.04] m∙min-1; respectively). Oxygen uptake (VO2), minute ventilation (VE), carbon dioxide production (VCO2) and heart rate (HR) increased until severe ([37.5-53.5] mL∙kg-1∙min-1, [55.8-96.3] L∙min-1, [32.2-51.5] mL∙kg-1∙min-1 and [152-182] bpm; respectively) and stabilized from severe to extreme (53.1 ± 8.4, mL∙kg-1∙min-1, 99.5 ± 19.1 L∙min-1, 49.7 ± 8.3 mL∙kg-1∙min-1 and 186 ± 11 bpm; respectively) while tidal volume (VT) was similar from low to severe ([2.02-2.18] L) and decreased at extreme intensities (2.08 ± 0.56 L). Lastly, the f R/SR ratio increased from low to heavy and decreased from severe to the extreme intensity domains (1.12 ± 0.24, 1.19 ± 0.25, 1.26 ± 0.26, 1.32 ± 0.26 and 1.23 ± 0.26). Conclusions: Our findings confirm a different ventilatory response pattern at extreme intensities when compared to the usually evaluated exertions. This novel insight helps to understand and characterize the maximal efforts in swimming and reinforces the importance to include extreme efforts in future swimming evaluations.

Mechanics and Energetic Analysis of Rowing with Big Blades with Randall Foils.

Empirical observations support that the addition of a plastic strip - also known as Randall foils - on the top edge of a rowing blade improves rowing efficiency during the cycle propulsive phase. The aim of the current study was to analyze the effect of using big blades with and without Randall foils on rowing performance. Twenty experienced rowers performed two 90 s tethered rowing bouts (with and without Randall foils) to assess their impact on force production and physiologic variables. All tests were randomized and a repeated measure design was used to compare experimental conditions. Higher values of peak and mean peak forces (479.4±134.7 vs. 423.2±153.0, d=0.83 and 376.5±101.4 vs. 337.1±113.3 N, d=0.68), peak oxygen uptake (47.9±7.5 vs. 45.3±7.3 mL∙kg-1∙min-1, d=0.19), peak blood lactate concentration (7.9±1.6 vs. 6.9±1.7 mmol∙L-1, d=0.16), blood lactate increasing speed (0.08±0.01 vs. 0.07±0.06 [(mmol·L-1)·s-1], d=0.27) and lactic anaerobic energy (27.4±7.9 vs. 23.4±8.1 kJ, d=0.23) were found for big blades with vs. without Randall foils, p<0.05. The current data suggest that the Randall foils can positively affect rowing performance.

Repeatability of ventilatory, metabolic and biomechanical responses to an intermittent incremental swimming protocol.

Objective. This study aimed to determine the repeatability of ventilatory, metabolic and biomechanical variables assessed at a large spectrum of front crawl swimming intensities. We hypothesized a strong agreement (combined with a small range of variation) between a typical step protocol performed in two experimental moments.Approach. Forty competitive swimmers performed a 7 × 200 m front crawl intermittent incremental protocol (0.05 m·s-1velocity rises and 30 s intervals) on two different occasions (48-72 h apart). Pulmonary gas exchange and ventilation were continuously measured breath-by-breath, metabolic variables were assessed during the intervals and biomechanical analysis was done at every protocol step.Main results. Concomitantly with the velocity increment, oxygen uptake, carbon dioxide production, ventilation, respiratory frequency, respiratory exchange ratio, averaged expiratory concentrations, end tidal oxygen and ventilatory equivalents for oxygen and carbon dioxide and blood lactate concentrations rose (p < 0.001), averaged expiratory concentrations and end tidal carbon dioxide and duration of inspiration, expiration and total breathing cycle decreased (p < 0.001), while tidal volume and volumes of oxygen and carbon dioxide expired maintained constant. Stroke frequency and stroke length increased and decreased (respectively) with the swimming velocity raise. No differences between experimental moments were observed in most of the assessed variables (p > 0.05), with a low dispersion (0.49%-9.94%) except for lactate concentrations and inspiration and expiration durations (11.00%-17.16%). Moderate-nearly perfect direct relationships and a good-excellent degree of reliability between moments were verified for all the assessed variables (r = 0.50-1.00, ICC = 0.76-1.00,p < 0.001), except for respiratory exchange ratio.Significance. The reliability analysis confirmed the repeatability of the assessed ventilatory, metabolic and biomechanical variables, with the obtained data well representing swimmers physiological condition when monitoring performance through a commonly used step protocol.

Post-swim oxygen consumption: assessment methodologies and kinetics analysis.

OBJECTIVE: This study aimed at comparing different recovery-based methods to assess the highest exercise oxygen uptake value ([Formula: see text]O2peak) when swimming at low-moderate, heavy and severe intensities. Complementarily, the different recovery curve kinetics were analysed. APPROACH: Eighteen competitive swimmers performed a 5 × 200 m front crawl intermittent protocol (0.05 m · s-1 increments and 3 min intervals), with respiratory gas exchange being continuously measured breath-by-breath during and post-exercise using a portable gas analyser. The directly determined [Formula: see text]O2peak ([Formula: see text]O2dir) was compared with the values obtained by linear and exponential backward extrapolations (of different intervals) and the recovery curve mathematical modelling. MAIN RESULTS: [Formula: see text]O2dir rose with intensity increase: 41.96 ± 6.22, 46.36 ± 6.89 and 50.97 ± 7.28 ml · kg-1 min-1 for low-moderate, heavy and severe swims. Linear and exponential regressions applied to the first 20 s of recovery presented the [Formula: see text]O2peak values closest to [Formula: see text]O2dir at low-moderate (42.80 ± 5.54 vs 42.88 ± 5.58 ml kg-1 min-1), heavy (47.12 ± 4.91 vs 47.48 ± 5.09 ml kg-1 min-1) and severe intensity domains (51.24 ± 6.89 vs 53.60 ± 8.54 ml kg-1 · min-1, respectively; r = 0.5-0.8, p < 0.05). The mono-exponential function was the best fit at low-moderate and heavy intensities, while the bi-exponential function better characterized the severe exercise domain (with a slow component amplitude, time delay and time constant of 6.2 ± 2.3 ml kg-1 min-1, 116.6 ± 24.3 and 39.9 ± 15.2 s, respectively). SIGNIFICANCE: The backward extrapolation of the first 20 s of recovery is the best method to assess the [Formula: see text]O2peak for a large spectrum of swimming intensities. Complementarily, intensity increases imply different recovery curve kinetics, particularly a mono-exponential behaviour for low-moderate and heavy exertions and a bi-exponential dynamics for severe paces.

Physiological and Biomechanical Evaluation of a Training Macrocycle in Children Swimmers.

Physiological responses related to 400-m front crawl performance were examined in a 11-week training macrocycle in children 11.6 ± 1.2 years old. Fourteen girls and twenty-nine boys completed a maximum intensity 400-m test, at the beginning (Τ1) and at the end of four weeks of general preparation (Τ2), four weeks of specific preparation (Τ3), and three weeks of the competitive period (Τ4). Blood lactate (La), blood glucose (Glu) and heart rate were measured post effort. Stroke rate (SR), stroke length (SL) and stroke index (SI) were measured during the test. The 400-m time was decreased at T2, T3, and T4 compared to T1 by 4.2 ± 4.9, 7.5 ± 7.0, and 8.6 ± 7.3% (p < 0.05) and at T3 and T4 compared to T2 by 3.1 ± 4.3 and 4.2 ± 4.6%, respectively (p < 0.05). La was not different between tests (p > 0.05) and Glu was decreased at T3 compared to other testing moments (p < 0.05). SR, SL, and SI were higher at T3 and T4 compared to T1 (p < 0.05). SL and SI were also increased at T4 compared to T2 (p < 0.05). Performance changes from T1 to T2 were related to SL and SI changes (r = 0.45 and 0.83, p < 0.05), and subsequent changes between T2 to T3 were related to SR, SI, La, and Glu changes (r = 0.48, 0.68, 0.34, and 0.42, p < 0.05). Performance change from T3 to T4 was related to SL, SI, and La modifications (r = 0.34, 0.70, and 0.53, p < 0.05). Performance gains may be related to various biomechanical or physiological changes according to training macrocycle structure.

Synthesis and evaluation of N-acylamino acids derivatives of triazenes. Activation by tyrosinase in human melanoma cell lines.

In this research work we report the synthesis of a new series of triazene prodrugs designed for Melanocyte-Directed Enzyme Prodrug Therapy (MDEPT). These compounds are derived from the N-acyltyrosine amino acid - a good enzyme substrate for the tyrosinase enzyme, which is significantly overexpressed in melanoma cells. We analysed their chemical stability and plasma enzymatic hydrolysis, and we also evaluated the release of the antitumoral drug in the presence of the tyrosinase. Subsequently, we performed the evaluation of the prodrug cytotoxicity in melanoma cell lines with different levels of tyrosinase activity. Prodrug 5c showed the highest cytotoxicity against melanoma cell lines, and this effect correlated well with the tyrosinase activity suggesting that prodrug cytotoxicity is tyrosinase-dependent.