High-intensity Interval Training Cycling Research Articles

164-OR: Role of Small Extracellular Vesicles for the Metabolic Response to Exercising in Insulin Resistant Humans

Small extracellular vesicles (SEV) are secreted into circulation after acute exercise suggesting a new mode of tissue crosstalk. High intensity interval training (HIIT) leads to improved insulin sensitivity and oxidative capacity in patients with type 2 diabetes. As the impact of HIIT on SEV release is unknown, this study examined its effects on number and proteome of SEV in insulin sensitive (IS) and insulin resistant (IR) humans to identify biomarkers for the early prediction of individual responses of insulin sensitivity to exercising. Eight T2D, 8 glucose tolerant IR and 6 IS humans with similar age and BMI (HbA1c in %: 7.4 ± 0.4, 5.3 ± 0.1, 5.5 ± 0.1; M-value in mg*kg-1*min-1: 1.8 ± 0.4, 4.1 ± 0.4, 7.2 ± 0.5) performed a 12-weeks HIIT cycling protocol for 3 days/week. Before the intervention (baseline) and 72 h after the last exercise bout, whole-body insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamps and serum samples were collected to isolate SEV by size exclusion chromatography. SEV size and number were measured by Nanoparticle Tracking Analysis and proteomic profiling was done by mass spectrometry using data independent acquisition. After 12 weeks of HIIT, T2D and IR improved their insulin sensitivity (M-value: T2D 3.5 ± 0.8, IR 6.2 ± 0.7; p<0.01 vs. baseline) and increased the number of circulating SEV by 52 ± 19% and 58 ± 21% (p<0.05 vs. baseline). Quantitative proteomic analysis of SEV revealed that HIIT regulated 258 proteins (118 in T2D, 125 in IR, 89 in IS) with an enrichment of proteins related to glycolysis in T2D, to antioxidative metabolism in IR and to lipid metabolism in IS. In conclusion, HIIT increases SEV number, but differently affects SEV mass and proteome in IS and IR humans, suggesting that SEV cargo could contribute to the individual response of insulin sensitivity to HIIT. Detailed characterization of SEV cargo can help to better understand the mechanisms of tissue crosstalk in the adaptation to exercise training and to develop novel exercise mimetics. Disclosure L. Mastrototaro: None. M. Apostolopoulou: None. S. Hartwig: None. D. Pesta: None. K. Strassburger: None. E. DeFilippo: None. Y. Karusheva: None. S. Gancheva: None. D.F. Markgraf: None. S. Lehr: None. K. Mussig: None. H. Al-Hasani: Consultant; Self; Bayer AG. J. Szendroedi: None. M. Roden: Advisory Panel; Self; Servier. Board Member; Self; Poxel SA. Consultant; Self; Eli Lilly and Company, Gilead Sciences, Inc., ProSciento, TARGET PharmaSolutions. Research Support; Self; Boehringer Ingelheim International GmbH, Novartis Pharma K.K., Sanofi US. Speaker’s Bureau; Self; Novo Nordisk A/S.

Heart Rate During an Exercise Test and Acute High-intensity Interval Training in Type 2 Diabetes.

To describe and compare the acute heart rate changes during an incremental exercise test and high-intensity interval training (HIIT) in subjects of different glucose control. Seventy-five adults were allocated into three groups: Normoglycaemic (NG, n=32), Pre- (PreT2D, n=30) and Type 2 diabetic (T2D, n=13) subjects. Subjects performed an incremental cycling test to determine cardiorespiratory fitness (VO2max), maximum heart rate (HRmax) and HR recovery post maximal effort, as well as a HIIT cycling session. HR variations are reported as HR pre (HR-preINT), and post interval (HR-postINT), percentage of maximum HR (%HRmax), delta of HR increased (∆HRINT), and delta HR recovery after each interval (∆HRR). By groups, there was a significant difference for the %HRmax in 1st and 2nd, but not in intervals 3rd to 10th between Pre-T2D and T2D groups. There were significant differences for the %HRmax in 1st to 2nd intervals between Pre-T2D and T2D groups. Significant (P<0.05) differences at some intervals were found for ΔHRINT, and ΔHRR. These findings suggest that the HR during an incremental exercise test, and from a typical 10-intervals based HIIT protocol could be used as an intensity marker for individuals independent of their glycaemic control.

6-week High-intensity Interval Training (HIIT) of the Lower Extremities Improves VO2max of the Upper Extremities.

High intensity interval training (HIIT) is widely used to improve VO2max. The purpose of this study was to examine if lower extremity HIIT resulted in improved maximal oxygen uptake (VO2max) and peak power output (PPO) of the upper extremities. Twenty healthy and trained participants (11 female and 9 male, VO2max 3160±1175 ml/min) underwent a 6-week HIIT program of the lower extremities on a cycle ergometer. Before and after the training period a maximal cycle ergometry (CE) and a maximal hand crank ergometry (HCE) were conducted to determine VO2max and PPO. Additionally, hematological parameters were determined. Increases in VO2max of the lower extremities (3160±1175 to 3449±1231 ml/min, p<0.001, η2p=0.779) as well as of the upper extremities (2255±938 to 2377±1015 ml/min, p=0.010, η2p=0.356) from pre- to post-test were found. PPO of the lower extremities increased (243±95 to 257±93 W, p<0.001, η2p=0.491), whereas it remained unchanged for the upper extremities (103±50 to 108±54 W, p=0.209, η2p=0.150). All hematological parameters increased. The results demonstrate that VO2max of the upper extremities increased after 6-weeks of cycling HIIT. However, upper body PPO was unchanged.

Perbandingan dua jenis olahraga pada pagi dan malam hari terhadap kualitas tidur

Pada dasarnya manusia melalui dua fase di dalam hidupnya yaitu fase ergotropic yang mana manusia beraktivitas pada pagi hari dan fase trophotropic yaitu manusia melakukan recovery di malam hari. Penelitian ini bertujuan untuk membandingan dua jenis olahraga yang dilakukan pada pagi dan di malam hari terhadap kualitas tidur. Metode penelitian yang digunakan adalah kuantitatif dan pendekatan deskriptif dengan perlakuan one shot case study design yang menggunakan 40 mahasiswa putra sebagai subjek penelitian yang terbagi dalam empat kelompok. Untuk mengetahui perbedaan kualitas tidur pada sesi pagi dan malam hari menggunakan uji independent samples t test. Berdasarkan hasil penelitian ini menunjukkan bahwa kualitas tidur pada kelompok yang yang melakukan aktivitas continuous cycling berintensitas sedang di sesi pagi dan malam hari memiliki nilai P &gt; 0,05 dan kualitas tidur pada kelompok yang melakukan aktivitas cycling with High Intensity Interval Training (HIIT) di sesi pagi dan malam hari memiliki nilai P &lt; 0,05. Kesimpulan dari penelitian ini adalah tidak terdapat perbedaan yang signifikan pada kualitas tidur antara kelompok yang melakukan aktivitas continuous cycling berintesitas sedang di pagi dan malam hari namun terdapat perbedaan yang signifikan pada kualitas tidur antara kelompok yang melakukan aktivitas cycling with HIIT di pagi dan malam hari.

Impairment of Cycling Capacity in the Heat in Well-Trained Endurance Athletes After High-Intensity Short-Term Heat Acclimation.

To investigate the effects of short-term, high-intensity interval-training (HIIT) heat acclimation (HA). Male cyclists/triathletes were assigned into either an HA (n = 13) or a comparison (COMP, n = 10) group. HA completed 3 cycling heat stress tests (HSTs) to exhaustion (60% Wmax; HST1, pre-HA; HST2, post-HA; HST3, 7 d post-HA). HA consisted of 30-min bouts of HIIT cycling (6min at 50% Wmax, then 12 × 1-min 100%-Wmax bouts with 1-min rests between bouts) on 5 consecutive days. COMP completed HST1 and HST2 only. HST and HA trials were conducted in 35°C/50% relative humidity. Cycling capacity and physiological and perceptual data were recorded. Cycling capacity was impaired after HIIT HA (77.2 [34.2]min vs 56.2 [24.4]min, P = .03) and did not return to baseline after 7 d of no HA (59.2 [37.4]min). Capacity in HST1 and HST2 was similar in COMP (43.5 [8.3] min vs 46.8 [15.7]min, P = .54). HIIT HA lowered resting rectal (37.0°C [0.3°C] vs 36.8°C [0.2°C], P = .05) and body temperature (36.0°C [0.3°C] vs 35.8°C [0.3°C], P = .03) in HST2 compared with HST1 and lowered mean skin temperature (35.4°C [0.5°C] vs 35.1°C [0.3°C], P = .02) and perceived strain on day 5 compared with day 1 of HA. All other data were unaffected. Cycling capacity was impaired in the heat after 5 d of consecutive HIIT HA despite some heat adaptation. Based on data, this approach is not recommended for athletes preparing to compete in the heat; however, it is possible that it may be beneficial if a state of overreaching is avoided.

Effects on Insulin Sensitivity, but Not on Mitochondrial Function Are Dependent on Insulin Resistance Status after High Intensity Interval Training

High intensity interval training (HIIT) is a time-efficient training approach to stimulate biogenesis in healthy populations. We hypothesized that HIIT would increase skeletal muscle insulin sensitivity due to improved muscle mitochondrial function in type 2 diabetes (T2D) patients and age- and BMI-matched controls (CON). We examined 18 sedentary male patients with T2D and 23 healthy male CON (age: 58±5 vs. 57±4 years, BMI: 31.4±2.4 vs. 30.4±2.3 kg.m-2) that were enrolled in a 12-week HIIT cycling protocol. CON were further grouped in insulin-sensitive (IS) and -resistant (IR) (baseline M in mg.kg-1.min-1; 7.4 ± 1.3 vs. 4.2 ± 1.1, p&amp;lt;0.001). Two-step hyperinsulinemic-euglycemic clamps, skeletal muscle biopsies for high resolution respirometry and magnetic resonance spectroscopy for liver fat quantification were performed. After 12 weeks of HIIT, T2D and IR CON increased their insulin sensitivity (3.9±1.9 vs. baseline: 2.7±1.6, p=0.02 and 5.5±2.1 vs. 4.2 ± 1.1, p=0.03, respectively), which returned to baseline after detraining. T2D and IR CON increased suppression of endogenous glucose production (EGP) during the high-insulin clamp (T2D: 91 ± 14% vs. baseline: 76 ± 11%, p=0.003 and IR CON: 107 ± 13% vs. 94 ± 14%, p=0.04). IR CON also increased suppression of lipolysis during the low-insulin clamp (82 ± 9 vs. 84 ± 8%, p=0.04). In T2D liver fat was decreased by 17% and remained decreased after detraining. Liver fat content remained unchanged by HIIT training in both CON groups. Muscle maximal uncoupled respiration increased in T2D and CON by 44% and 48%, respectively, at 12 weeks and remained increased after detraining in all groups (p&amp;lt;0.01). We conclude that at the same level of insulin resistance HIIT training improved hepatic and peripheral insulin sensitivity in patients with T2D and insulin resistant controls whereas changes in mitochondrial function occurred irrespective of insulin resistance status. Disclosure M. Apostolopoulou: None. D. Pesta: None. Y. Karusheva: None. S. Gancheva: None. T. Jelenik: None. A. Bierwagen: None. K. M ssig: None. J. Szendroedi: None. M. Roden: Speaker's Bureau; Self; Boehringer Ingelheim GmbH. Research Support; Self; Boehringer Ingelheim GmbH. Consultant; Self; Poxel SA. Research Support; Self; Danone Nutricia Early Life Nutrition, GlaxoSmithKline plc., Nutricia Advanced Medical Nutrition, Sanofi.

Is high-intensity interval cycling feasible and more beneficial than continuous cycling for knee osteoarthritic patients? Results of a randomised control feasibility trial.

BackgroundKnee osteoarthritis (OA) patients often suffer joint pain and stiffness, which contributes to negative changes in body composition, strength, physical performance (function), physical activity and health-related quality of life. To reduce these symptoms and side effects of knee OA, moderate-intensity continuous training (MICT) cycling is often recommended. While resistance training is considered the optimal form of training to improve sarcopenic outcomes, it imposes higher joint loads and requires supervision, either initially or continuously by trained exercise professionals. Therefore, this pilot study sought to gain some insight into the feasibility and potential benefits of high-intensity interval training (HIIT) cycling as an alternative exercise option to MICT cycling for individuals with knee OA.MethodsTwenty-seven middle-aged and older adults with knee OA were randomly allocated to either MICT or HIIT, with both programs involving four unsupervised home-based cycling sessions (∼25 min per session) each week for eight weeks. Feasibility was assessed by enrolment rate, withdrawal rate, exercise adherence and number of adverse effects. Efficacy was assessed by health-related quality of life (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Lequesne index), physical function (Timed Up and Go (TUG), Sit to Stand (STS) and preferred gait speed) and body composition (body mass, BMI, body fat percentage and muscle mass).ResultsTwenty-seven of the interested 50 potential participants (54%) enrolled in the study, with 17 of the 27 participants completing the trial (withdrawal rate of 37%); with the primary withdrawal reasons being unrelated injuries or illness or family related issues. Of the 17 participants who completed the trial, exercise adherence was very high (HIIT 94%; MICT 88%). While only three individuals (one in the MICT and two in the HIIT group) reported adverse events, a total of 28 adverse events were reported, with 24 of these attributed to one HIIT participant. Pre–post-test analyses indicated both groups significantly improved their WOMAC scores, with the HIIT group also significantly improving in the TUG and STS. The only significant between-group difference was observed in the TUG, whereby the HIIT group improved significantly more than the MICT group. No significant changes were observed in the Lequesne index, gait speed or body composition for either group.DiscussionAn unsupervised home-based HIIT cycle program appears somewhat feasible for middle-aged and older adults with knee OA and may produce similar improvements in health-related quality of life but greater improvements in physical function than MICT. These results need to be confirmed in larger randomised controlled trials to better elucidate the potential for HIIT to improve outcomes for those with knee OA. Additional research needs to identify and modify the potential barriers affecting the initiation and adherence to home-based HIIT cycling exercise programs by individuals with knee OA.