Aim: To quantify the physiological demands and impact of muscle function t of the Fran workout, one of the most popular CrossFit benchmarks. Methods: Twenty experienced CrossFitters—16 male: 29 (6) years old and 4 female: 26 (5) years old— performed 3 rounds (with 30-s rests in between) of 21–21, 15–15, and 9–9 front squats to overhead press plus pull-up repetitions. Oxygen uptake and heart rate were measured at baseline, during the workout, and in the recovery period. Rating of perceived exertion, blood lactate, and glucose concentrations were assessed at rest, during the intervals, and in the recovery period. Muscular fatigue was also monitored at rest and at 5 minutes, 30 minutes, and 24 hours postexercise. Repeated-measures analysis of variance was performed to compare time points. Results: Aerobic (52%–29%) and anaerobic alactic (30%–23%) energy contributions decreased and the anaerobic lactic contribution increased (18%–48%) across the 3 rounds of the Fran workout. Countermovement jump height decreased by 8% (−12 to −3) mean change (95% CI), flight duration by 14% (−19 to −7), maximum velocity by 3% (−5 to −0.1), peak force 4% (−7 to −0.1), and physical performance (plank prone 47% [−54 to −38]) were observed. Conclusions: It appears that the Fran workout is a physically demanding activity that recruits energy from both aerobic and anaerobic systems. This severe-intensity workout evokes substantial postexercise fatigue and corresponding reduction in muscle function.

The current study aimed to longitudinally evaluate anthropometric, physiological, and biomechanical variables related to middle-distance performance during a 45-week swimming training season. Thirty-four swimmers (age: 12.07 ± 1.14 years) performed a maximum of 400 m front crawl at the beginning (T1) and finish of the first macrocycle (T2, 15 weeks) and the finish of the second (T3, 18 weeks) and third macrocycles (T4, 12 weeks). Time-related variables, stroke rate (SR), stroke length (SL), and stroke index (SI) were recorded during the test, and blood lactate ([La]) and glucose ([Glu]) concentrations were measured post-exercise. The time of the 400 m effort decreased after each macrocycle (T2 vs. T1, 7.8 ± 5.6%; T3 vs. T2, 3.7 ± 3.1%; T4 vs. T3, 3.8 ± 3.4%; p < 0.01). Four hundred meter speed changes between T1 and T2 were positively related to variations in [La], [Glu], SL, and SI (r = 0.36–0.60, p < 0.05). Changes between T2 and T3 were related to SI only (r = 0.5, p < 0.05), and modifications between T3 and T4 were associated with SL and SI variations (r = 0.34 and 0.65, p < 0.05). These results indicate that a well-structured year plan including three macrocycles leads to a significant age-group swimming performance improvement, mostly connected with an increase in technical proficiency.

We aimed to analyze the impact of a single CrossFit® session “workout of the day” (WOD) on plasma redox. Ten CrossFit®-experienced subjects volunteered to participate. Oxygen uptake (VO2) during WOD and treadmill running (TR), performed at the same VO2 and time as WOD, were continuously monitored. Venous blood samples were collected before (baseline—BL) and after both exercises, for lactate concentration, total antioxidant capacity, thiol content, and DNA damage measurements. Total antioxidant capacity decreased after both exercises (WOD and TR) vs. BL, with no differences between exercises. Thiol content increased after WOD; however, no differences between exercises were observed. DNA damage increased after both WOD and TR, although more exuberantly after WOD than TR. Much higher lactate levels were detected in WOD compared to TR. Our findings suggest that WOD induces an increased condition of oxidative injury and affects total antioxidant capacity in experienced CrossFit® performers.

The current study aimed to evidence the strengths and weaknesses of two indirect methods for assessing the anaerobic alactic contribution to a specific CrossFit® workout. Thirty experienced crossfitters performed the Fran workout at maximal intensity, and ventilatory data were collected during the recovery period using a telemetric portable gas analyser to assess the oxygen uptake (VO2) of the off-kinetics fast component (Anarecovery). The kinetics of maximal phosphocreatine splitting (AnaPCr) were determined based on the literature. No differences between the two methods were observed (31.4 ± 4.0 vs. 30.4 ± 4.1 kJ for Anarecovery and AnaPCr, respectively). Despite the existence of some caveats (e.g., errors derived from a delay at the onset of VO2 recovery and the assumption of given values in the concentration of phosphocreatine per kilogram of wet muscle, respectively) in both methods, the data indicate that they yield similar results and allow for estimations of alactic energy contribution from a short-duration and high intensity CrossFit® routine. The current data contributes to CrossFit® workout evaluations and training strategies, helping researchers to evaluate crossfitters more accurately. The advantage of the two methods used in the current study is that they are non-invasive, which differs greatly from muscle biopsies.

Empirical observations supports that the addition of a plastic strip - also known as Randall foils - on the top edge of a rowing blade improve 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 its 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 positivly affect rowing performance.