Extremely Low-Volume Burpee Interval Training Equivalent to 8 Minutes Per Session Improves Vertical Jump Compared with Sprint Interval Training in Real-World Circumstances.

ABSTRACT: Pérez-Ifrán, P, Magallanes, CA, de S. Castro, FA, Astorino, TA, and Benítez-Flores, S. Extremely low-volume burpee interval training equivalent to 8 minutes per session improves vertical jump compared with sprint interval training in real-world circumstances. J Strength Cond Res 38(1): 10-20, 2024-The aim of this study was to compare the cardiometabolic and physical effects of 2 time-matched high-intensity programs in a real-world environment. Forty-three active and healthy adults (sex = 31 men and 12 women; age = 27 ± 5 years; peak heart rate [HR peak ] = 190.7 ± 10.6 beat·min -1 ) were randomized to 2 very low-volume protocols (∼8 minutes): sprint interval training (SIT) ( n = 15), burpee interval training (BIT) ( n = 15), and control (CON) ( n = 13). Subjects in SIT and BIT performed 5 days of 10 × 4 second "all-out" efforts with 30 seconds of recovery. Body composition, blood pressure, countermovement jump (CMJ), 10-m sprint, shuttle run test (SRT), autonomic modulation , self-efficacy, and intention were evaluated before and after training. Sprint interval training elicited a higher %HR peak , energy expenditure, rating of perceived exertion category ratio 10 scale, and feeling scale than BIT ( p < 0.05). SRT distance was significantly improved in SIT ( p = 0.03, d = 0.62), whereas CMJ height was significantly enhanced in BIT ( p = 0.0014, d = 0.72). Self-efficacy progressively worsened for SIT than for BIT as sessions increased, and significant differences were found in 5× a week frequency between protocols ( p = 0.040, d = 0.79). No differences in intention to engage were detected between the regimens ( p > 0.05). No changes were observed in body composition, blood pressure, 10-m sprint, SRTV̇O 2max , or autonomic variables with training ( p > 0.05). Results exhibit that extremely low-volume SIT improved running performance, whereas BIT increased the vertical jump.

Physiological and Psychological Responses to Three Distinct Exercise Training Regimens Performed in an Outdoor Setting: Acute and Delayed Response.

The aim of this study was to compare the acute responses to three time-matched exercise regimens. Ten trained adults (age, maximum oxygen consumption (VO2max), and body mass index (BMI) = 25.9 ± 5.6 yr, 50.9 ± 5.4 mL·kg-1·min-1, and 22.1 ± 1.8 kg·m-2) completed sprint interval training (SIT) requiring 14 × 5 s efforts with 35 s of recovery, high-intensity interval training (HIIT) consisting of 18 × 15 s efforts at ~90% of peak heart rate (HRpeak) with 15 s of recovery, and vigorous continuous training (CT) consisting of 8.75 min at ~85 %HRpeak, in randomized order. Heart rate, blood lactate concentration, rating of perceived exertion, affective valence, and enjoyment were monitored. Moreover, indices of neuromuscular function, autonomic balance, diet, mental stress, incidental physical activity (PA), and sleep were measured 24 h after each session to analyze the magnitude of recovery. Both HIIT and CT exhibited a greater %HRpeak and time ≥ 90 %HRpeak than SIT (p < 0.05). Blood lactate and rating of perceived exertion were higher in response to SIT and HIIT vs. CT (p < 0.05); however, there were no differences in enjoyment (p > 0.05). No differences were exhibited in any variable assessed along 24 h post-exercise between conditions (p > 0.05). These data suggest that HIIT and CT accumulate the longest duration at near maximal intensities, which is considered a key factor to enhance VO2max.

Reproductive Dysfunction from Exercise Training: The "Exercise-Hypogonadal Male Condition".

The objective of this short review is to discuss how exercise training in men can result in changes in the reproductive system similar to those observed in women who develop athletic amenorrhea or suffer the Female Athlete Triad. Men chronically exposed to training for endurance sports exhibit persistently reduced basal free and total testosterone concentrations without concurrent luteinizing hormone elevations. These men are deemed to have the "Exercise-Hypogonadal Male Condition" (EHMC). Broadly, dysfunction in the hypothalamic-pituitary-gonadal regulatory axis is associated with either of these states. In women this effect on the axis is linked to the existence of a low energy availability (LEA) state, research in men relative to LEA is ongoing. The exact physiological mechanism inducing the reduction of testosterone in these men is currently unclear but is postulated to be a dysfunction within the hypothalamic-pituitary-gonadal regulatory axis. The potential exists for the reduced testosterone concentrations within EHMC men to be disruptive and detrimental to some anabolic-androgenic testosterone-dependent physiological processes. Findings, while limited, suggest spermatogenesis problems may exist in some cases; thus, infertility risk in such men is a critical concern. Present evidence suggests the EHMC condition is limited to men who have been persistently involved in chronic endurance exercise training for an extended period of time, and thus is not a highly prevalent occurrence. Nevertheless, it is critical that endocrinologist and fertility clinicians become more aware of the existence of EHMC as a potential problem-diagnosis in their male patients who exercise.

El objetivo de esta breve revisión es describir cómo el entrenamiento físico en hombres puede provocar cambios en el sistema reproductivo similares a los observados en mujeres que desarrollan amenorrea atlética o manifiestan la tríada de la mujer atleta. Hombres expuestos sistemáticamente a entrenamientos para deportes de resistencia exhiben concentraciones de testosterona libre y basal reducidas, pero sin manifestar un aumento simultáneo de hormona luteinizante. Esta condición se denomina "hipogonadismo masculino producto del ejercicio" (EHMC, por su siglas en inglés). Ambos estados están asociados a una disfunción en el eje hipotalámico-hipofisario-gonadal. En las mujeres, la alteración del eje está vinculada a un estado de baja disponibilidad energética (BDE); en los hombres, la investigación relacionada con la BDE está en curso. El mecanismo fisiológico exacto que induce la reducción de testosterona en estos hombres aún no está claro, pero se postula que es una disfunción dentro del eje regulador hipotalámico-hipofisario-gonadal. Existe la posibilidad de que las bajas concentraciones de testosterona de los hombres con EHMC sean disruptivas y perjudiciales para algunos procesos fisiológicos anabólicoandrogénicos dependientes de testosterona. Los hallazgos, aunque limitados, sugieren que en algunos casos pueden existir problemas de espermatogénesis; por lo tanto, el riesgo de infertilidad en tales hombres es una preocupación crucial. La evidencia actual sugiere que el EHMC se limita a hombres que han estado involucrados en entrenamiento de resistencia de manera persistente y durante tiempo prolongado, por lo que el EHMC no es una condición prevalente. De todos modos, es fundamental que médicos endocrinólogos y especialistas en fertilidad estén atentos a la existencia del EHMC como potencial problema ­ y diagnostico ­ que pueden padecer sus pacientes deportistas varones.