Cardiorespiratory Fitness Improvements Following Low‐Frequency Training Are Not Inferior to High‐Frequency Training Matched for Intensity and Volume

Scandinavian Journal of Medicine and Science in Sports, Journal Year: 2025, Volume and Issue: 35(2)

Published: Feb. 1, 2025

ABSTRACT Epidemiological evidence suggests low‐frequency physical activity provides health benefits, but the physiological impacts of weekly training frequency are understudied. We investigated whether “Weekend Warrior” (WW) was inferior to traditional, high‐frequency (HF) for improving maximal oxygen uptake (V̇O 2 max). The secondary aim assess integrative adaptations each protocol. Twenty‐eight sedentary‐to‐recreationally‐active adults aged 18–45 years (14 males and 14 females) were randomized perform 8‐weeks HF or WW on a cycle ergometer (either four two sessions weekly, respectively), consisting continuous interval exercise, with intensity volume matched between groups. not V̇O max (mean ± standard deviation; WW: 43.5 6.5 vs. 47.8 6.4 mL/kg/min; HF: 42.3 6.2 47.3 6.7; main effect training, p < 0.001). Severe domain cycling time‐to‐task‐failure also increased in both groups (WW: 3.7 1.6 8.6 3.2 min; 3.5 0.9 7.7 2.8; training: Frequency did affect improvements hemoglobin mass 771 203 790 189 g; 754 185 765 202; = 0.043) skeletal muscle oxidative capacity 0.034 0.008 0.045 0.015 s −1 ; 0.036 0.011 0.041 0.010; 0.002), nor it influence cardiorespiratory, substrate oxidation, voluntary contractile, perceptual responses submaximal exercise (interaction effect: > 0.05 all outcomes). Eight weeks improved wide range outcomes no difference frequencies, suggesting that distribution has limited during short‐term training. Trial Registration: This trial registered at ClinicalTrials.gov identifier: NCT05908578

Language: Английский

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Muscle fatigue and interference phenomenon during concurrent aerobic and strength training: An alternative hypothetical model

Medical Hypotheses, Journal Year: 2025, Volume and Issue: unknown, P. 111614 - 111614

Published: March 1, 2025

Language: Английский

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Session duration affects the magnitude of post-exercise hypervolemia but not the erythropoietin response to acute high-intensity interval exercise

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 8, 2024

ABSTRACT The increase in plasma volume ∼24 hours post-exercise may act as an erythropoietic signal, but this mechanism’s responsiveness to different exercise prescription variables is poorly understood. purpose of study was determine the impact high-intensity interval duration on and related responses. On separate days, 16 healthy, recreationally active participants (n=8 males; n=8 females) performed four (4×4) or eight intervals (8×4) consisting 4 min at 105% critical power with 3 recovery. Venous blood samples collected before, immediately after, 24 after each HIIT session were used measure hemoglobin concentration hematocrit calculate changes. Erythropoietic regulating hormone concentrations measured using ELISA kits. Plasma decreased both protocols (4×4: −4.4±3.5%, p<0.05; 8×4: −4.4±3.6%, p<0.05) only significantly elevated above baseline 8×4 protocol +1.0±7.1%, p>0.05; +5.6±4.6%, p<0.05). Erythropoietin ([EPO]) higher than Pre vs h post: 6.5±3.1 vs. 7.1±3.3 mIU/mL; 6.9±3.7 7.3±3.7 main effect time, no difference between (p>0.05). [Aldosterone] 0 295±151 544±259 pg/mL; 335±235 821±553 pg/mL), caused a larger (interaction effect, That hypervolemia be duration-dependent not required for increases circulating EPO has important implications endurance training aiming oxygen delivery tissues. NEWS AND NOTEWORTHY This first show that common length (4 x min) extended (8 similarly increased [erythropoietin] exercise, despite transiently increasing volume. Previous works have investigated regulation following durations, explored links signalling. study’s findings relevance understanding physiology exercise-induced erythropoiesis.

Language: Английский

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Sex differences in the cardiopulmonary and neuromuscular response to high-intensity interval exercise

Published: Nov. 11, 2024

Abstract Sex differences exist in the integrative response to exercise, however, these are typically researched during constant-load exercise. Interval exercise involves high-intensity efforts interspersed with recovery periods repeatedly stress physiological systems, and it is currently unknown whether this form of differs between sexes. Ten males ten females (age: 25±3 years) completed two experimental visits. First, an incremental treadmill test was performed obtain submaximal (lactate threshold) maximal ( O 2peak ) data. Thereafter, visit involved 4 × 3-min running intervals at 90% final velocity (v ), 90 secs rest intervals. Before after each interval, voluntary contraction (MVC), quadriceps potentiated twitch (Q tw.pot activation (VA) were recorded. The rates oxygen uptake 2 carbon dioxide production CO ventilation E continuously recorded throughout. There no sex difference relative (males: 47.2±6.0 vs. females: 44.4±5.8 ml.kg - 1. min -1 , p=0.292). When expressed peak values, there or interval task (p≥0.781). Females had greater / values first (p≤0.046). reductions MVC, Q VA (p≥0.150), however lesser post-exercise (−24±9 −15±8%, p=0.044). Compared males, experienced hyperpnoea initial stages, decreases contractile function post-exercise.

Language: Английский

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