scholarly journals Stimulus Level during Endurance Training: Effects on Lactate Kinetics in Untrained Men

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Michael Tuttor ◽  
Simon von Stengel ◽  
Michael Hettchen ◽  
Wolfgang Kemmler
Keyword(s):  
Interval Training ◽  
Stimulus Level ◽  
Moderate Intensity ◽  
Time To Exhaustion ◽  
Lactate Kinetics ◽  
High Intensity Interval ◽  
Underlying Mechanisms ◽  
The Individual ◽  
Total Workload ◽  
Continuous Running

Background/Objective. Not only but particularly due to their time efficiency, High-Intensity Interval Training (HIIT) is becoming increasingly popular in fitness-oriented endurance sports. The purpose of this study was to determine the effect of a HIIT running program versus a Moderate Intensity Continuous Exercise (MICE) training running program (16 weeks each) on lactate kinetics in untrained males. Methods. 65 healthy but untrained males (30-50 years, BMI: 27.2 ± 3.7kg/m2) were randomly assigned to either an HIIT (n=33) or a waiting-control/MICE group (n=32). HIIT consisted of intervals and intense continuous running bouts at or above the individual anaerobic threshold (IANS, 95-110% of IANS-HR), while MICE focused on continuous running at 70-82.5% IANS-HR. Both programs were adjusted for “total workload”. Study endpoints were time to IANS and time from IANS till “time to exhaustion” (TTE) as assessed by stepwise treadmill test. Results. In both exercise groups time to reach IANS (MICE: 320 ± 160 s versus HIIT: 198 ± 118 s) increased significantly (p<.001), with the groups differing significantly (p<.001). Time from IANS until TTE was prolonged significantly among the HIIT group (27 ± 66s, p=.030), while among the MICE group a significant reduction of time from IANS until TTE (59 ± 109s; p=.017) was determined. Between-group difference is significant (p=.003) for this parameter. In both groups TTE increased significantly (HIIT: 27.2 ± 17.7% versus MICE: 29.0 ± 19.4%, both p<.001) at a similar level (p=.279). Conclusion. HIIT and MICE protocols, when adjusted for total workload, similarly increased running performance in untrained male subjects; however, the underlying mechanisms differ fundamentally. Due to its effects on aerobic and anaerobic performance improvement, HIIT can be recommended for untrained individuals as a time-efficient alternative or complementary training method to MICE. However, our protocol did not confirm the general superiority of HIIT versus MICE on the key endurance parameter “time to exhaustion” that has been reported by other comparative exercise studies.

scholarly journals Intra-individual physiological response of recreational runners to different training mesocycles: a randomized cross-over study

2020 ◽  
Vol 120 (12) ◽  
pp. 2705-2713
Author(s):  
Peter Düking ◽  
Hans-Christer Holmberg ◽  
Philipp Kunz ◽  
Robert Leppich ◽  
Billy Sperlich
Keyword(s):  
Interval Training ◽  
High Volume ◽  
Physiological Adaptation ◽  
Time To Exhaustion ◽  
High Intensity Interval Training ◽  
Recreational Runners ◽  
Uptake Velocity ◽  
And Performance ◽  
High Intensity Interval ◽  
The Individual

Abstract Purpose Pronounced differences in individual physiological adaptation may occur following various training mesocycles in runners. Here we aimed to assess the individual changes in performance and physiological adaptation of recreational runners performing mesocycles with different intensity, duration and frequency. Methods Employing a randomized cross-over design, the intra-individual physiological responses [i.e., peak ($${\dot{\text V}}{\text O}_{2 {\rm peak}}$$ V ˙ O 2 peak ) and submaximal ($${\dot{\text V}}{\text O}_{2 {\rm submax}}$$ V ˙ O 2 submax ) oxygen uptake, velocity at lactate thresholds (V2, V4)] and performance (time-to-exhaustion (TTE)) of 13 recreational runners who performed three 3-week sessions of high-intensity interval training (HIIT), high-volume low-intensity training (HVLIT) or more but shorter sessions of HVLIT (high-frequency training; HFT) were assessed. Results $${\dot{\text V}}{\text O}_{2 {\rm submax}}$$ V ˙ O 2 submax , V2, V4 and TTE were not altered by HIIT, HVLIT or HFT (p > 0.05). $${\dot{\text V}}{\text O}_{2 {\rm peak}}$$ V ˙ O 2 peak improved to the same extent following HVLIT (p = 0.045) and HFT (p = 0.02). The number of moderately negative responders was higher following HIIT (15.4%); and HFT (15.4%) than HVLIT (7.6%). The number of very positive responders was higher following HVLIT (38.5%) than HFT (23%) or HIIT (7.7%). 46% of the runners responded positively to two mesocycles, while 23% did not respond to any. Conclusion On a group level, none of the interventions altered $${\dot{\text V}}{\text O}_{2 {\rm submax}}$$ V ˙ O 2 submax , V2, V4 or TTE, while HVLIT and HFT improved $${\dot{\text V}}{\text O}_{2 {\rm peak}}$$ V ˙ O 2 peak . The mean adaptation index indicated similar numbers of positive, negative and non-responders to HIIT, HVLIT and HFT, but more very positive responders to HVLIT than HFT or HIIT. 46% responded positively to two mesocycles, while 23% did not respond to any. These findings indicate that the magnitude of responses to HIIT, HVLIT and HFT is highly individual and no pattern was apparent.

scholarly journals Acute and Chronic Effects of Low-Volume High-Intensity Interval Training Compared to Moderate-Intensity Continuous Training on Glycemic Control and Body Composition in Older Women with Type 2 Diabetes

Obesities ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 72-87
Author(s):  
Alexis Marcotte-Chénard ◽  
Dominic Tremblay ◽  
Marie-Michelle Mony ◽  
Pierre Boulay ◽  
Martin Brochu ◽  
...  
Keyword(s):  
Body Composition ◽  
Older Women ◽  
Interval Training ◽  
Moderate Intensity ◽  
Continuous Training ◽  
Glucose Levels ◽  
Mild Hyperglycemia ◽  
Low Volume ◽  
High Intensity Interval

Objective: To compare the acute and chronic effects of low-volume high-intensity interval training (HIIT) to moderate-intensity continuous training (MICT) on glycemic control, body composition and continuous glucose monitoring (CGM) in older women with type 2 diabetes (T2D). Methods: Thirty older women (68 ± 5 years) with T2D were randomized in two groups—HIIT (75 min/week) or MICT (150 min/week). Glucose homeostasis (A1c, glucose, insulin, HOMA-IR2) and body composition (iDXA) were measured before and after the 12-week exercise intervention. During the first and last week of training (24-h before and 48-h after exercise), the following CGM-derived data were measured: 24-h and peak glucose levels, glucose variability and time spent in hypoglycemia as well as severe and mild hyperglycemia. Results: While lean body mass increased (p = 0.035), total and trunk fat mass decreased (p ≤ 0.007), without any difference between groups (p ≥ 0.81). Fasting glucose levels (p = 0.001) and A1c (p = 0.014) significantly improved in MICT only, with a significant difference between groups for fasting glucose (p = 0.02). Neither HIIT nor MICT impacted CGM-derived data at week 1 (p ≥ 0.25). However, 24-h and peak glucose levels, as well as time spent in mild hyperglycemia, decreased in HIIT at week 12 (p ≤ 0.03). Conclusion: These results suggest that 12 weeks of low-volume HIIT is enough to provide similar benefit to MICT for body composition and improve the acute effect of exercise when measured with CGM.

Training-induced changes in muscle contraction patterns enhance exercise performance after short-term neuromuscular electrical stimulation

2020 ◽  
Vol 28 (4) ◽  
pp. 339-350
Author(s):  
Gökhan Umutlu ◽  
Nevzat Demirci ◽  
Nasuh Evrim Acar
Keyword(s):  
Electrical Stimulation ◽  
Muscle Contraction ◽  
Exercise Performance ◽  
Controlled Trial ◽  
Dynamic Control ◽  
Neuromuscular Electrical Stimulation ◽  
Interval Training ◽  
Time To Exhaustion ◽  
Muscle Strengthening ◽  
The Individual

BACKGROUND: Neuromuscular electrical stimulation (NMES) is a complementary tool for therapeutic exercise for muscle strengthening and may potentially enhance exercise performance. OBJECTIVE: To determine whether high-intensity interval training (HIIT) and continuous aerobic training (CA) coupled with NMES enhance the changes in the eccentric/concentric muscle contraction patterns of hamstring and quadriceps. METHODS: Forty-five healthy sedentary male participants performed cycling training 3 times per week for 8 weeks combined with/without NMES performed at a load equivalent to 65% and 120% of IVO2max (intensity associated with the achievement of maximal oxygen uptake). Anthropometrics, blood lactate measurements, IVO2max, TLimVO2max (time-to-exhaustion) and isokinetic strength parameters were measured at baseline and post-training using a randomized controlled trial. RESULTS: The conventional hamstring-to-quadriceps-ratio (HQR: Hcon/Qcon) at 60∘/s and the Dynamic Control Ratio (DCR: Hecc/Qcon) at 180∘/s significantly increased both in the dominant (D) and non-dominant (ND) limb in the HIIT + NMES group (p< 0.05). There was a positive significant correlation between the individual changes in D HQR at 60∘/s and IVO2max (r= 0.94, p= 0.005) and the DCR at 180∘/s and TLimVO2max (r= 0.90, p= 0.015), respectively. CONCLUSIONS: The increases in the eccentric muscle contraction and DCR following HIIT + NMES seem to improve fatigue tolerance, cause less fatigue and oxidative stress on the lower limb during pedaling at high intensities.

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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