High-intensity interval training speeds the adjustment of pulmonary O2 uptake, but not muscle deoxygenation, during moderate-intensity exercise transitions initiated from low and elevated baseline metabolic rates

2013 ◽  
Vol 114 (11) ◽  
pp. 1550-1562 ◽  
Author(s):  
Alexandra M. Williams ◽  
Donald H. Paterson ◽  
John M. Kowalchuk
Keyword(s):  
High Intensity ◽  
Time Course ◽  
Interval Training ◽  
Constant Load ◽  
Moderate Intensity ◽  
Metabolic Rates ◽  
High Intensity Interval Training ◽  
Moderate Intensity Exercise ◽  
Muscle Deoxygenation ◽  
High Intensity Interval

During step transitions in work rate (WR) within the moderate-intensity (MOD) exercise domain, pulmonary O2 uptake (V̇o2p) kinetics are slowed, and V̇o2p gain (ΔV̇o2p/ΔWR) is greater when exercise is initiated from an elevated metabolic rate. High-intensity interval training (HIT) has been shown to speed V̇o2p kinetics when step transitions to MOD exercise are initiated from light-intensity baseline metabolic rates. The effects of HIT on step transitions initiated from elevated metabolic rates have not been established. Therefore, this study investigated the effects of HIT on V̇o2p kinetics during transitions from low and elevated metabolic rates, within the MOD domain. Eight young, untrained men completed 12 sessions of HIT (spanning 4 wk). HIT consisted of 8–12 1-min intervals, cycling at a WR corresponding to 110% of pretraining maximal WR (WRmax). Pre-, mid- and posttraining, subjects completed a ramp-incremental test to determine maximum O2 uptake, WRmax, and estimated lactate threshold (θ̂L). Participants additionally completed double-step constant-load tests, consisting of step transitions from 20 W → Δ45% θ̂L [lower step (LS)] and Δ45 → 90% θ̂L [upper step (US)]. HIT led to increases in maximum O2 uptake ( P < 0.05) and WRmax ( P < 0.01), and τV̇o2p of both lower and upper MOD step transitions were reduced by ∼40% (LS: 24 s → 15 s; US: 45 s → 25 s) ( P < 0.01). However, the time course of adjustment of local muscle deoxygenation was unchanged in the LS and US. These results suggest that speeding of V̇o2p kinetics in both the LS and US may be due, in part, to an improved matching of muscle O2 utilization to microvascular O2 delivery within the working muscle following 12 sessions of HIT, although muscle metabolic adaptations cannot be discounted.

scholarly journals High intensity interval training (HIIT) as a viable alternative to induce the prevention of respiratory diseases: a point of view of exercise immunology during COVID-19 outbreak

2020 ◽  
Vol 9 (10) ◽  
pp. e7069109186
Author(s):  
Carolina Cavalcante de Paula ◽  
Sergio Machado ◽  
Gustavo De Conti Teixeira Costa ◽  
Marcelo Magalhães Sales ◽  
Thiago Gottgtroy Miranda ◽  
...  
Keyword(s):  
High Intensity ◽  
Lower Cost ◽  
Adaptive Immune System ◽  
Interval Training ◽  
Moderate Intensity ◽  
Low Grade ◽  
High Intensity Interval Training ◽  
Moderate Intensity Exercise ◽  
Cost Of Time ◽  
High Intensity Interval

The immune system's response against SARS-Cov-2 seems crucial to control viral infection, since this system is homeostatic, dynamic and promotes immunoprotection of the organism through the activation of the innate and adaptive immune system via activation of cellular and chemical complexes that recognize, neutralize, metabolize and eliminate heterologous substances, with or without tissue damage. An obesogenic microenvironment can further increase the risk of disease complications, and cause a more virulent viral strain and a more lethal virus. Moreover, physical inactivity as well as poor eating habits impairs the body's energy metabolism and immune cells due to low-grade chronic inflammation. Studies suggest that light to moderate exercise, as well as mild calorie restriction, as an effective approach to relieve obesity and therefore an interesting strategy to strengthen the immune response during the outbreak of COVID-19, while a vaccine is not developed. Some studies have been shown significant findings in favor of High intensity interval training (HIIT) protocols when compared to moderate intensity exercise, showing how immunological system responds to vigorous to high intensity training. However, HIIT has a lower cost of time, reducing the time/efficiency ratio, that is, a lower cost of time with similar or even better benefits to higher volume exercise programs. Let us not forget: "time is the most precious asset we have".

scholarly journals The effects of different protocols of physical exercise and rest on long-term memory

2019 ◽  
Author(s):  
Wesley Pyke ◽  
Fadi Ifram ◽  
Laura Coventry ◽  
Yee Sung ◽  
Isabelle Champion ◽  
...  
Keyword(s):  
Physical Exercise ◽  
High Intensity ◽  
Interval Training ◽  
Moderate Intensity ◽  
Long Term Memory ◽  
High Intensity Interval Training ◽  
Moderate Intensity Exercise ◽  
Term Memory ◽  
High Intensity Interval

Objectives Many studies have looked at the effects of physical exercise on long-term memory. However, to date, no study has compared the effect of different intensities and protocols of physical exercise and different rest conditions on long-term memory. Methods In three studies (N=59) we measured the extent that physical exercise (in its varying intensities) and wakeful rest (active-rest; in which participants were cognitively engaged while seated and passive-rest; no cognitive engagement while seated) could influence long-term memory. Across all three studies, nearly identical procedures were employed, using the same old/new recognition memory test in order to establish the most effective protocol for cognitive enhancement. In Study 1, the effects of continuous moderate intensity exercise, uninterrupted wakeful rest (passive) and rest with an engagement task (active) were explored. In Study 2, continuous moderate intensity exercise was compared to high-intensity interval training (HIIT) and passive rest. Study 3 observed the effects of low-, moderate- and high-intensity continuous exercise. Results Across the three studies moderate intensity exercise had the greatest positive impact on memory performance. Passive rest was more effective than active rest, however, less than high-intensity interval-training (HIIT). Conclusion Our findings suggest that it is not necessary to physically overexert oneself in order to achieve observable improvements to long-term memory. By also investigating uninterrupted wakeful rest, it reaffirmed the importance of the consolidation period for the formation of long-term memories.

Short-term high-intensity interval training improves phosphocreatine recovery kinetics following moderate-intensity exercise in humans

2008 ◽  
Vol 33 (6) ◽  
pp. 1124-1131 ◽  
Author(s):  
Sean C. Forbes ◽  
Jill M. Slade ◽  
Ronald A. Meyer
Keyword(s):  
Skeletal Muscle ◽  
High Intensity ◽  
Interval Training ◽  
Oxidative Capacity ◽  
Moderate Intensity ◽  
High Intensity Interval Training ◽  
Short Term ◽  
Moderate Intensity Exercise ◽  
Leg Extension ◽  
High Intensity Interval

Previous studies have shown that high-intensity training improves biochemical markers of oxidative potential in skeletal muscle within a 2-week period. The purpose of this study was to examine the effect of short-term high-intensity interval training on the time constant (τ) of phosphocreatine (PCr) recovery following moderate-intensity exercise, an in vivo measure of functional oxidative capacity. Seven healthy active subjects (age, 21 ± 4 years; body mass, 69 ± 11 kg) performed 6 sessions of 4–6 maximal-effort 30 s cycling intervals within a 2-week period, and 7 subjects (age, 24 ± 5 years; body mass, 80 ± 15 kg) served as controls. Prior to and following training, phosphorous-31 magnetic resonance spectroscopy (31P-MRS; GE 3T Excite System) was used to measure relative changes in high-energy phosphates and intracellular pH of the quadriceps muscles during gated dynamic leg-extension exercise (3 cycles of 90 s exercise and 5 min of rest). A monoexponential model was used to estimate the τ of PCr recovery. The τ of PCr recovery after leg-extension exercise was reduced by 14% with high-intensity interval training (pretraining, 43 ± 14 s vs. post-training, 37 ± 15 s; p < 0.05) with no change in the control group (44 ± 12 s vs. 43 ± 12 s, respectively; p > 0.05). These findings demonstrate that short-term high-intensity interval training is an effective means of increasing functional oxidative capacity in skeletal muscle.

High-intensity interval training improves interventricular synchrony and strain under hypoxic stress in sedentary males

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y.C Huang ◽  
J.S Wang
Keyword(s):  
High Intensity ◽  
Interval Training ◽  
Moderate Intensity ◽  
Control Group ◽  
Funding Source ◽  
Peak Strain ◽  
High Intensity Interval Training ◽  
The Difference ◽  
High Intensity Interval ◽  
Longitudinal Strains

Abstract Background Interventricular interactions in increased RV afterload such as hypoxia stress, which affects both synchrony and function in an in-series effect as well as a parallel effect arising from leftward septal shift. Improved myocardial contractility is a critical circulatory adaptation to exercise training, however, the types of exercise that can improve interventricular synchrony under hypoxic environment have not yet been established. Purpose This study investigates how high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) influence on the interventricular synchrony in response to normobaric hypoxia in sedentary men. Methods Fifty-four sedentary males were randomized to perform HIIT (3-minute intervals at 40% and 80% VO2peak, n=18), MICT (sustained 60% VO2peak, n=18) for 30 minutes/day, 5 days/week for 6 weeks and the control group (CTL, n=18). Synchrony measurements at apical 4-chamber view including (1) intra-delay, the difference in time to peak strain (TS) between segmental septal-to-lateral ventricular or atrial walls, and (2) inter-delay, the difference in TS between RV or RA free wall and LV or LA lateral wall. The data were acquired by 2-dimensional speckle tracking echocardiography at rest under hypoxic condition (12% FIO2, simulated an altitude of 4,500 m) before and after the interventions. Results HIIT had significantly elevated radial and longitudinal strains in both LA and LV (p&lt;0.05). As the results showed, HIIT was superior than MICT in improvement of longitudinal intra-delay of LV; furthermore, only HIIT simultaneously ameliorated both radial and longitudinal synchrony at apex. Although the HIIT enhanced intraventricular synchrony in both motions, whereas the interventricular synchrony deteriorated at radial motion. In atrium synchrony, although both groups augmented the intra-LA synchrony, however, only HIIT reduced the inter-delay between LA and RA at the roof motion. LV end-systolic volume (ESV) significantly correlated with the longitudinal inter-delay of ventricle (r=−0.53, p&lt;0.05), whereas the LV end-diastolic volume (EDV) correlated with the inter-delay of atrium in roof motion (r=0.40, p&lt;0.05). Conclusion We found differences between HIIT and MICT in segmental intra- and inter- synchrony. HIIT enhanced both ventricular or atrial synchrony, and further increased the EDV coupled with decreased ESV. These findings give new insight into cardiac adaptation to difference endurance training and the long-term impact of such changes warrants future study in cardiac diseases. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Science Council of Taiwan

Moderate-intensity continuous training and high-intensity interval training improve cognition, and BDNF levels of middle-aged overweight men

2021 ◽  
Author(s):  
Neumir Sales de Lima ◽  
Ricardo Augusto Leoni De Sousa ◽  
Fabiano Trigueiro Amorim ◽  
Fernando Gripp ◽  
Caíque Olegário Diniz e Magalhães ◽  
...  
Keyword(s):  
High Intensity ◽  
Interval Training ◽  
Moderate Intensity ◽  
High Intensity Interval Training ◽  
Middle Aged ◽  
Continuous Training ◽  
High Intensity Interval

scholarly journals The Effects of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Heart Rate Variability in Physically Inactive Adults

2018 ◽  
Vol 15 (7) ◽  
pp. 1508 ◽  
Author(s):  
Abdullah Alansare ◽  
Ken Alford ◽  
Sukho Lee ◽  
Tommie Church ◽  
Hyun Jung
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Intensity ◽  
Interval Training ◽  
Moderate Intensity ◽  
High Intensity Interval Training ◽  
Continuous Training ◽  
Significant Interaction Effect ◽  
High Intensity Interval ◽  
Physically Inactive

Physically inactive adults are prevalent worldwide. This study compared the effects of short-term high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on heart rate variability (HRV) in physically inactive adults as a preliminary study. Thirteen physically inactive male adults (27.5 ± 3.80 years) were randomly assigned to HIIT (N = 7) or MICT (N = 6). The HIIT program consisted of 20 min of interval training with cycling to rest ratio of 10/50 s at ≥90% HRpeak, while the MICT program consisted of 40 min of continuous cycling at 60–75% HRpeak. Both groups completed eight sessions of training within two weeks. Time and frequency domains of HRV were measured for 20 min with Actiwave-Cardio monitor (CamNtech, UK). The number of R-R interval and inter-beat interval (IBI) were significantly improved (p < 0.05) in both HIIT and MICT programs following eight sessions of training. A significant interaction effect for group by time was found in the lnLF/HF ratio (p < 0.05) where it was only improved in the HIIT group from pre- to post-test. The HIIT program is superior to MICT in improving HRV in physically inactive adults. The HIIT program can be applied as a time-efficient program for improving cardiac-autoregulation.

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