scholarly journals Technical feasibility of constant-load and high-intensity interval training for cardiopulmonary conditioning using a re-engineered dynamic leg press

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Farouk Chrif ◽  
Tobias Nef ◽  
Kenneth J Hunt
Keyword(s):  
High Intensity ◽  
Ventilatory Threshold ◽  
Interval Training ◽  
Constant Load ◽  
Work Rate ◽  
High Intensity Interval Training ◽  
Leg Press ◽  
Cardiopulmonary Exercise ◽  
The Difference ◽  
High Intensity Interval

Abstract Background Leg-press devices are one of the most widely used training tools for musculoskeletal strengthening of the lower-limbs, and have demonstrated important cardiopulmonary benefits for healthy and patient populations. Further engineering development was done on a dynamic leg-press for work-rate estimation by integrating force and motion sensors, power calculation and a visual feedback system for volitional work-rate control. This study aimed to assess the feasibility of the enhanced dynamic leg press for cardiopulmonary exercise training in constant-load training and high-intensity interval training. Five healthy participants aged 31.0±3.9 years (mean ± standard deviation) performed two cardiopulmonary training sessions: constant-load training and high-intensity interval training. Participants carried out the training sessions at a work rate that corresponds to their first ventilatory threshold for constant-load training, and their second ventilatory threshold for high-intensity interval training. Results All participants tolerated both training protocols, and could complete the training sessions with no complications. Substantial cardiopulmonary responses were observed. The difference between mean oxygen uptake and target oxygen uptake was 0.07±0.34 L/min (103 ±17%) during constant-load training, and 0.35±0.66 L/min (113 ±27%) during high-intensity interval training. The difference between mean heart rate and target heart rate was −7±19 bpm (94 ±15%) during constant-load training, and 4.2±16 bpm (103 ±12%) during high-intensity interval training. Conclusions The enhanced dynamic leg press was found to be feasible for cardiopulmonary exercise training, and for exercise prescription for different training programmes based on the ventilatory thresholds.

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<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<0.05), whereas the LV end-diastolic volume (EDV) correlated with the inter-delay of atrium in roof motion (r=0.40, p<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

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.

Cardiac rehabilitation in the paediatric Fontan population: development of a home-based high-intensity interval training programme

2020 ◽  
Vol 30 (10) ◽  
pp. 1409-1416
Author(s):  
Michael Khoury ◽  
Devin B. Phillips ◽  
Peter W. Wood ◽  
William R. Mott ◽  
Michael K. Stickland ◽  
...  
Keyword(s):  
Adverse Events ◽  
High Intensity ◽  
Training Session ◽  
Interval Training ◽  
High Intensity Interval Training ◽  
Cardiopulmonary Exercise ◽  
Home Based ◽  
Fontan Physiology ◽  
High Intensity Interval ◽  
Training Protocol

AbstractIntroduction:We evaluated the safety and feasibility of high-intensity interval training via a novel telemedicine ergometer (MedBIKE™) in children with Fontan physiology.Methods:The MedBIKE™ is a custom telemedicine ergometer, incorporating a video game platform and live feed of patient video/audio, electrocardiography, pulse oximetry, and power output, for remote medical supervision and modulation of work. There were three study phases: (I) exercise workload comparison between the MedBIKE™ and a standard cardiopulmonary exercise ergometer in 10 healthy adults. (II) In-hospital safety, feasibility, and user experience (via questionnaire) assessment of a MedBIKE™ high-intensity interval training protocol in children with Fontan physiology. (III) Eight-week home-based high-intensity interval trial programme in two participants with Fontan physiology.Results:There was good agreement in oxygen consumption during graded exercise at matched work rates between the cardiopulmonary exercise ergometer and MedBIKE™ (1.1 ± 0.5 L/minute versus 1.1 ± 0.5 L/minute, p = 0.44). Ten youth with Fontan physiology (11.5 ± 1.8 years old) completed a MedBIKE™ high-intensity interval training session with no adverse events. The participants found the MedBIKE™ to be enjoyable and easy to navigate. In two participants, the 8-week home-based protocol was tolerated well with completion of 23/24 (96%) and 24/24 (100%) of sessions, respectively, and no adverse events across the 47 sessions in total.Conclusion:The MedBIKE™ resulted in similar physiological responses as compared to a cardiopulmonary exercise test ergometer and the high-intensity interval training protocol was safe, feasible, and enjoyable in youth with Fontan physiology. A randomised-controlled trial of a home-based high-intensity interval training exercise intervention using the MedBIKE™ will next be undertaken.

Acute High-Intensity Interval Training Improves Tvent and Peak Power Output in Highly Trained Males

2002 ◽  
Vol 27 (4) ◽  
pp. 336-348 ◽  
Author(s):  
Paul B. Laursen ◽  
Michelle A. Blanchard ◽  
David G. Jenkins
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Ventilatory Threshold ◽  
Interval Training ◽  
Peak Power Output ◽  
Control Group ◽  
High Intensity Interval Training ◽  
High Intensity Interval

This study examined the effects of four high-intensity interval-training (HIT) sessions performed over 2 weeks on peak volume of oxygen uptake [Formula: see text] the first and second ventilatory thresholds (VT1, VT2) and peak power output (PPO) in highly trained cyclists. Fourteen highly trained male cyclists [Formula: see text] performed a ramped cycle test to determine [Formula: see text]VT1, VT2, and PPO. Subjects were divided equally into a HIT group and a control group. The HIT group performed four HIT sessions (20 × 60 s at PPO, 120 s recovery); the [Formula: see text] test was repeated < 1 wk after the HIT program. Control subjects maintained their regular training program and were reassessed under the same timeline. There was no change in [Formula: see text] for either group; however, the HIT group showed a significantly greater increase in VT1 (+22% vs. −3%), VT2 (+15% vs. −1%), and PPO (+4.3 vs. −4%) compared to controls (all P < .05). This study has demonstrated that HIT can improve VT1, VT2 and PPO, following only four HIT sessions in already highly trained cyclists. Key words: cycling, cyclists, heart rate, oxygen uptake, short-term training, ventilatory threshold

Comparison of continuous moderate training with high intensity interval training on cardiopulmonary exercise test variables in patients with coronary artery disease: A meta-analysis

2020 ◽  
Vol 19 (1) ◽  
pp. 40
Author(s):  
Francisco Tiago Oliveira De Oliveira ◽  
Paula Guerra Duplat ◽  
Cristiane Maria Carvalho Costa Dias
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Exercise Test ◽  
High Intensity ◽  
Interval Training ◽  
Cardiopulmonary Exercise Test ◽  
High Intensity Interval Training ◽  
Cardiopulmonary Exercise ◽  
Artery Disease ◽  
High Intensity Interval

Background: Cardiovascular rehabilitation has the objective of reducing the risks of mortality and within this intervention there are two training modalities: high intensity interval training (HIIT) and moderate continuous intensity training (MIT). The exercise prescription is performed by cardiopulmonary exercise test. There are differences about which one is the best training for this patient. Aim: To compare the effects of HIIT and moderate continuous training on the variables of the cardiopulmonary exercise test (CPX) in patients with coronary artery disease. Methods: This is a systematic review of randomized clinical trials on coronary artery disease. This study was registered on PROSPERO. The search was executed on the databases: Medline, Scielo, Lilacs and Pedro. The selection of studies was a two-phase process: Reading of title and abstract and reading of full article. The data extraction was performed by the transcription of information. The methodological quality was evaluated by the PEDro scale and the risk of bias scale. The statistical analysis was performed using the RStudio software by random effect model and was applied the Q-Cochran test to evaluate the statistical heterogeneity. Results: 10 clinical trials were included. The methodological quality assessed by PEDro generated scores of four to nine, and the bias risk scale detected a low risk of bias. For the variables:  VO2 peak (p = 0.04), Ventilatory Threshold (p = 0.05), HR max (p = 0.01), SBP max (p = 0.02), the HIIT proved to be more effective. The other variables did not present differences between the two modalities. Conclusion: HIIT showed to be the most effective training modality for the increase of VO2 max, Ventilatory Threshold, SBP max and HR max.Keywords: coronary heart disease, high intensity interval training, moderate continuous training.

scholarly journals Effort and duration matched ‘High Intensity Interval Training’ using cycle ergometry compared to leg press resistance training

2019 ◽  
Author(s):  
Marcelo Henrique Silva ◽  
Cláudio André Barbosa de Lira ◽  
James Steele ◽  
James Fisher ◽  
João Felipe Mota ◽  
...  
Keyword(s):  
Resistance Training ◽  
Cardiorespiratory Fitness ◽  
Lower Limb ◽  
High Intensity ◽  
Interval Training ◽  
Knee Extension ◽  
Cycle Ergometry ◽  
High Intensity Interval Training ◽  
Leg Press ◽  
High Intensity Interval

Purpose: Exercises for increasing muscle strength and cardiorespiratory fitness are traditionally prescribed separately, based on the different characteristics of the modalities and the adaptations that each typically promotes. This separation has been questioned by recent studies that suggest that the intensity of effort at which the exercise is performed seems to impart greater influence than the equipment involved. Based on this assumption, it has been proposed that ‘cardio’ training and resistance training might promote similar adaptations as long as effort and duration are equated. The objective of the present study was to compare two ‘High Intensity Interval Training’ protocols matched for effort and duration using different exercise modalities, leg press (resistance training) and cycle ergometry (‘cardio’), upon changes in muscle strength, cardiorespiratory fitness, and lower limb composition in recreationally trained men. Methods: Twenty-five trained men (28.9 ± 5.6 years, 6.6 ± 5.6 years of training experience) were randomly divided into two groups. One group performed sprint interval training on a cycle ergometer (4 sets of 30 seconds sprints) and the other performed leg press (4 sets of 10-12 repetitions to momentary failure). Both groups trained three times a week for 5 weeks. Before and after the training period, the participants performed a 10-repetition maximum (10RM) for knee extension, An incremental exercise test on a treadmill for time to exhaustion (TTE) and peak oxygen consumption (V ̇O2peak), and underwent dual energy X-ray absorptiometry to assess lower limb composition. Results: Knee extension 10RM and TTE increased in both groups with no statistically significant between group difference (p = 0.614 and p = 0.210). There was a statistically significant between group difference for change in V ̇O2peak (p = 0.023) with only the cycle ergometer group showing a significant within group increase. For all lower limb composition outcomes, changes were minimal. Conclusion: The results of the present study suggest that 5 weeks of effort and duration matched ‘High Intensity Interval Training’ using cycle ergometry ‘cardio’ or leg press resistance training may produce similar strength and endurance (TTE) adaptations. However, ‘cardio’ modality training may produce greater increases in cardiorespiratory fitness.

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