scholarly journals High Intensity Interval Training to Increase Tolerance for Exercise Intensity

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1763-1763
Author(s):  
James Roemmich ◽  
Kelsey Ufholz ◽  
Kyle Flack ◽  
Tori Kaster ◽  
William Siders

Abstract Objectives Increasing the reinforcing value of a stimulus occurs after repeated exposures to the reinforcer via neuroadaptations that increase the incentive salience of the stimulus. Exercise is a reinforcer and increasing exercise reinforcement (RRVex) may be dependent on simultaneously increasing tolerance for exercise intensity. Positive outcome expectancy (POE) of participating in an intervention can be an important determinant of treatment efficacy, such as when attempting to increase tolerance for exercise intensity or RRVex. We hypothesized that (1) high-intensity interval training (HIIT) that produces great discomfort would increase tolerance for exercise intensity, (2) adding a positive outcome expectancy (POE) component to HIIT would further increase tolerance for exercise intensity and, (3) increases in tolerance for exercise discomfort would mediate increases in RRVex. Methods A randomized controlled trial with a factorial design included HIIT + POE (n = 33 adults, n = 19 women) and HIIT-only (n = 33, n = 19 women) groups. Both groups participated in HIIT 3 d/wk for 6 wks. HIIT + POE received POE treatment each exercise session. Outcomes were measured at baseline, after 6 weeks of HIIT, and 4 weeks post-HIIT (10 wk). Changes in the RRVex were assessed by a progressive ratio schedule of reinforcement task. Other outcomes were outcome expectations, tolerance for exercise intensity, and behavior regulations of exercise. Results Outcome expectancy did not change in either group. Tolerance for exercise discomfort increased (P < .001) above baseline by 12% at 6 wk and 13% at 10 wk. Intrinsic, integrated, and identified behavior regulations of exercise were all increased (P < .01) at 6 wk and remained so at 10 wk. However, RRVex was not changed and change in RRVex was not correlated with change in tolerance for exercise intensity. Conclusions HIIT increases tolerance for exercise intensity and intrinsic, integrated, and identified behavior regulations of exercise. Funding Sources USDA-ARS.

2019 ◽  
Author(s):  
Cesare Granata ◽  
Rodrigo S.F. Oliveira ◽  
Jonathan P. Little ◽  
David J. Bishop

ABSTRACTExercise-induced increases in peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and p53 protein content in the nucleus mediate the initial phase of exercise-induced mitochondrial biogenesis. Here we investigated if exercise-induced increases in these and other markers of mitochondrial biogenesis were altered after 40 sessions of twice-daily high-volume high-intensity interval training (HVT) in human skeletal muscle. Vastus lateralis muscle biopsies were collected from 10 healthy recreationally active participants before, immediately post, and 3h after a session of HIIE performed at the same absolute exercise intensity before and after HVT (Pre-HVT and Post-HVT, respectively). The protein content of common markers of exercise-induced mitochondrial biogenesis were assessed in nuclear- and cytosolic-enriched fractions by immunoblotting; mRNA contents of key transcription factors and mitochondrial genes were assessed by qPCR. Despite exercise-induced increases in PGC-1α, p53, and plant homeodomain finger-containing protein 20 (PHF20) protein content, the phosphorylation of p53 and acetyl-CoA carboxylase (p-p53Ser15 and p-ACCSer79, respectively), and PGC-1α mRNA Pre-HVT, no significant changes were observed Post-HVT. Forty sessions of twice-daily high-intensity interval training blunted all of the measured exercise-induced molecular events associated with mitochondrial biogenesis that were observed Pre-HVT. Future studies should determine if this loss relates to the decrease in relative exercise intensity, habituation to the same exercise stimulus, or a combination of both.


2020 ◽  
Vol 105 (8) ◽  
pp. e2941-e2959 ◽  
Author(s):  
Benjamin J Ryan ◽  
Michael W Schleh ◽  
Cheehoon Ahn ◽  
Alison C Ludzki ◽  
Jenna B Gillen ◽  
...  

Abstract Objective We compared the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on insulin sensitivity and other important metabolic adaptations in adults with obesity. Methods Thirty-one inactive adults with obesity (age: 31 ± 6 years; body mass index: 33 ± 3 kg/m2) completed 12 weeks (4 sessions/week) of either HIIT (10 × 1-minute at 90%HRmax, 1-minute active recovery; n = 16) or MICT (45 minutes at 70%HRmax; n = 15). To assess the direct effects of exercise independent of weight/fat loss, participants were required to maintain body mass. Results Training increased peak oxygen uptake by ~10% in both HIIT and MICT (P < 0.0001), and body weight/fat mass were unchanged. Peripheral insulin sensitivity (hyperinsulinemic-euglycemic clamp) was ~20% greater the day after the final exercise session compared to pretraining (P < 0.01), with no difference between HIIT and MICT. When trained participants abstained from exercise for 4 days, insulin sensitivity returned to pretraining levels in both groups. HIIT and MICT also induced similar increases in abundance of many skeletal muscle proteins involved in mitochondrial respiration and lipid and carbohydrate metabolism. Training-induced alterations in muscle lipid profile were also similar between groups. Conclusion Despite large differences in training intensity and exercise time, 12 weeks of HIIT and MICT induce similar acute improvements in peripheral insulin sensitivity the day after exercise, and similar longer term metabolic adaptations in skeletal muscle in adults with obesity. These findings support the notion that the insulin-sensitizing effects of both HIIT and MICT are mediated by factors stemming from the most recent exercise session(s) rather than adaptations that accrue with training.


2019 ◽  
Vol 126 (2) ◽  
pp. 431-443 ◽  
Author(s):  
Pierce Boyne ◽  
Colleen Meyrose ◽  
Jennifer Westover ◽  
Dustyn Whitesel ◽  
Kristal Hatter ◽  
...  

Aerobic exercise may acutely prime the brain to be more responsive to rehabilitation, thus facilitating neurologic recovery from conditions like stroke. This aerobic priming effect could occur through multiple mechanisms, including upregulation of circulating brain-derived neurotrophic factor (BDNF), increased corticospinal excitability, and decreased intracortical inhibition. However, optimal exercise parameters for targeting these mechanisms are poorly understood. This study tested the effects of exercise intensity on acute BDNF and neurophysiological responses. Sixteen ambulatory persons >6 mo poststroke performed three different 20-min exercise protocols in random order, approximately 1 wk apart, including the following: 1) treadmill high-intensity interval training (HIT-treadmill); 2) seated-stepper HIT (HIT-stepper); and 3) treadmill moderate-intensity continuous exercise (MCT-treadmill). Serum BDNF and transcranial magnetic stimulation measures of paretic lower limb excitability and inhibition were assessed at multiple time points during each session. Compared with MCT-treadmill, HIT-treadmill elicited significantly greater acute increases in circulating BDNF and corticospinal excitability. HIT-stepper initially showed BDNF responses similar to HIT-treadmill but was no longer significantly different from MCT-treadmill after decreasing the intensity in reaction to two hypotensive events. Additional regression analyses showed that an intensity sufficient to accumulate blood lactate appeared to be important for eliciting BDNF responses, that the interval training approach may have facilitated the corticospinal excitability increases, and that the circulating BDNF response was (negatively) related to intracortical inhibition. These findings further elucidate neurologic mechanisms of aerobic exercise and inform selection of optimal exercise-dosing parameters for enhancing acute neurologic effects. NEW & NOTEWORTHY Acute exercise-related increases in circulating BDNF and corticospinal excitability are thought to prime the brain for learning. Our data suggest that these responses can be obtained among persons with stroke using short-interval treadmill high-intensity interval training, that a vigorous aerobic intensity sufficient to generate lactate accumulation is needed to increase BDNF, that interval training facilitates increases in paretic quadriceps corticospinal excitability, and that greater BDNF response is associated with lesser intracortical inhibition response.


2020 ◽  
Vol 318 (2) ◽  
pp. E224-E236 ◽  
Author(s):  
Cesare Granata ◽  
Rodrigo S. F. Oliveira ◽  
Jonathan P. Little ◽  
David J. Bishop

Exercise-induced increases in peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and p53 protein content in the nucleus mediate the initial phase of exercise-induced mitochondrial biogenesis. Here, we investigated whether exercise-induced increases in these and other markers of mitochondrial biogenesis were altered after 40 sessions of twice-daily high-volume, high-intensity interval training (HVT) in human skeletal muscle. Vastus lateralis muscle biopsies were collected from 10 healthy recreationally active participants before, immediately postexercise, and 3 h after a session of high-intensity interval exercise (HIIE) performed at the same absolute exercise intensity before and after HVT (pre-HVT and post-HVT, respectively). The protein content of common markers of exercise-induced mitochondrial biogenesis was assessed in nuclear- and cytosolic-enriched fractions by immunoblotting; mRNA contents of key transcription factors and mitochondrial genes were assessed by qPCR. Despite exercise-induced increases in PGC-1α, p53, and plant homeodomain finger-containing protein 20 (PHF20) protein content, the phosphorylation of p53 and acetyl-CoA carboxylase (p-p53 Ser15 and p-ACC Ser79, respectively), and PGC-1α mRNA Pre-HVT, no significant changes were observed post-HVT. Forty sessions of twice-daily high-intensity interval training blunted all of the measured exercise-induced molecular events associated with mitochondrial biogenesis that were observed pre-HVT. Future studies should determine whether this loss relates to the decrease in relative exercise intensity, habituation to the same exercise stimulus, or a combination of both.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257685
Author(s):  
Katie L. Hesketh ◽  
Hannah Church ◽  
Florence Kinnafick ◽  
Sam O. Shepherd ◽  
Anton J. M. Wagenmakers ◽  
...  

Objective High intensity interval training (HIIT) is a time-efficient exercise modality to improve cardiorespiratory fitness, and has recently been popularised by social media influencers. However, little is known regarding acute physiological and perceptual responses to these online protocols compared to HIIT protocols used within research. The aim was to investigate acute physiological, perceptual and motivational responses to two HIIT protocols popular on social media, and compare these to two evidence-based protocols. Methods Twenty-seven recreationally active (>1 exercise session /week) participants (Age: 22±3y, BMI: 24.3±2.4) completed a randomised cross-over study, whereby each participant completed four HIIT protocols, two already established in research (Ergo-60:60 (cycling 10x60s at 100%Wmaxwith 60s rest), BW-60:60 (body-weight exercises 10x60swith 60s rest)) and two promoted on social media (SM-20:10 (body-weight exercises 20x20swith 10s rest) and SM-40:20 (body-weight exercises 15x40s with 20s rest)). Blood lactate, heart rate (HR), feeling scale (FS), felt arousal scale (FSA), enjoyment and perceived competence were measured in response to each protocol. Results Significant differences were observed between BW-60:60 and SM-20:10 for the proportion of intervals meeting the ACSM high-intensity exercise criterion (>80% of HRmax) (BW-60:60 93±10%, SM-20:10 74±20%, P = 0.039) and change in lactate (BW-60:60 +7.8±3.7mmol/L, SM-20:10 +5.5±2.6mmol/L, P = 0.001). The percentage of time spent above the criterion HR was also significantly lower in SM-20:10 compared to all other protocols (Ergo-60:60 13.9±4.9min, BW-60:60 13.5±3.5min, SM-40:20 12.1±2.4min, SM-20:10 7.7±3.1, P<0.05). No differences were observed in lowest reported FS between protocols (P = 0.268), but FS decreased linearly throughout Ergo-60:60 and BW-60:60 (first vs. last interval P<0.05), but not in SM-20:10 or SM-40:20 (P>0.05). Enjoyment was higher upon completion of BW-60:60 compared to Ergo-60:60 and SM-40:20 (P<0.05). Conclusions This study shows that HIIT protocols available on social media offer an interesting real-world alternative for promoting exercise participation. Future studies should continue to investigate these highly popular and practical HIIT protocols.


2020 ◽  
Vol 45 (6) ◽  
pp. 591-600 ◽  
Author(s):  
Ana Kovacevic ◽  
Barbara Fenesi ◽  
Emily Paolucci ◽  
Jennifer J. Heisz

Aerobic exercise may enhance memory in older adults. However, the optimal intensity and underlying mechanism are unclear. This community-based study examined the effect of aerobic exercise intensity on memory and general cognitive abilities. Brain-derived neurotrophic factor (BDNF) was examined as a potential mechanism. Sixty-four sedentary older adults participated in 1 of 3 groups: (i) high-intensity interval training (HIIT); (ii) moderate continuous training (MCT); or (iii) stretching control (CON). Prior to and following the intervention, high-interference memory was assessed using a Mnemonic Similarity task and executive functions were assessed using Go Nogo and Flanker tasks. HIIT led to the greatest memory performance compared with MCT and CON (F[2,55] = 6.04, p = 0.004) and greater improvements in memory correlated with greater increases in fitness (rs (46) = 0.27, p = 0.03). Exercise intensity seemed to matter less for executive functioning, as positive trends were observed for both HIIT and MCT. No significant differences in BDNF were found between groups. Overall, these results suggest that aerobic exercise may enhance memory in older adults, with the potential for higher intensity exercise to yield the greatest benefit. While our findings suggest that BDNF does not regulate these adaptations, the mechanisms remain to be determined. Novelty High-intensity interval training results in the greatest memory performance in inactive older adults compared with moderate continuous training or stretching. Improvement in fitness correlates with improvement in memory performance.


2020 ◽  
Vol Volume 11 ◽  
pp. 77-84 ◽  
Author(s):  
Okba Selmi ◽  
Ibrahim Ouergui ◽  
Danielle E. Levitt ◽  
Pantelis T Nikolaidis ◽  
Beat Knechtle ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document