- Title
- High intensity interval training (HIIT) produces small improvements in fasting glucose, insulin, and insulin resistance in sedentary older men but not masters athletes
- Creator
- Hayes, Lawrence; Herbert, Peter; Sculthorpe, Nicholas; Grace, Fergal
- Date
- 2020
- Type
- Text; Journal article
- Identifier
- http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/174021
- Identifier
- vital:14768
- Identifier
-
https://doi.org/10.1016/j.exger.2020.111074
- Identifier
- ISBN:0531-5565 (ISSN)
- Abstract
- The aim of this study was to investigate whether 6 weeks' high intensity interval training (HIIT; 6 × 30 s sprints at 40% peak power, once every five days) following 6 weeks' of aerobic preconditioning could favourably affect fasting insulin, glucose, and the homeostatic model assessment of insulin resistance (HOMA1-IR) in sedentary older men compared with masters athletes. A secondary aim was to establish whether lifelong exercisers (LEX) exhibited improved fasting insulin, glucose, and HOMA1-IR, compared to sedentary older males (SED). Twenty-two males (62 ± 2 years) comprised the SED group and 17 males (60 ± 5 years) were enrolled as LEX. Participants were tested at phase A (baseline), B (after preconditioning), and C (post-HIIT). There was no effect of time (P = 0.116) or interaction (P = 0.727) on insulin. However, there was an effect of group (P < 0.001). In terms of magnitude, HIIT induced a small decrease in SED insulin compared to baseline (15.8 ± 8.1 uIU·ml−1 at baseline and 14.0 ± 7.8 uIU·ml−1 post-HIIT; Cohen's d = 0.23) and compared to post-preconditioning (17.5 ± 9.7 uIU·ml−1; Cohen's d = 0.40). LEX insulin was unchanged throughout (all differences were trivial). Insulin was lower in LEX than SED at phase A (P < 0.001, Cohen's d = 1.31), B (P = 0.023, Cohen's d = 0.78), and C (P = 0.004, Cohen's d = 1.01). There was no effect of time (P = 0.290), group (P = 0.166), or interaction (P = 0.153) for glucose. In terms of magnitude, HIIT produced a small reduction in SED glucose compared to baseline (5.7 ± 1.3 mmol·l−1 at baseline and 5.3 ± 0.9 mmol·l−1 post-HIIT; Cohen's d = 0.36), and compared to phase B (5.6 ± 0.8 mmol·l−1, Cohen's d = 0.35). LEX glucose was unchanged throughout (all changes were trivial). SED had moderately higher blood glucose than LEX at phase A (Cohen's d = 0.49), and B (Cohen's d = 0.63), but only a trivial difference existed at phase C (Cohen's d = 0.15). There was no effect of time (P = 0.110), or interaction (P = 0.569) on HOMA1-IR. However, there was an effect of group (P = 0.002). In terms of magnitude, SED HOMA1-IR was unchanged from phase A to B (4.2 ± 3.0 and 4.5 ± 2.9 arbitrary units respectively [Cohen's d = 0.10]). However, at C (3.5 ± 2.6) there was a small decrease compared to B (Cohen's d = 0.36), and A (Cohen's d = 0.25). LEX experienced a small increase in HOMA1-IR from phase A to B (1.6 ± 1.3 and 2.3 ± 2.8 respectively [Cohen's d = 0.32]), followed by a small decrease from B to C (1.7 ± 1.1 at phase C [Cohen's d = 0.28]), and a trivial change from A to C (Cohen's d = 0.08). HOMA1-IR was lower in LEX than SED at baseline (P = 0.002, Cohen's d = 1.12), after preconditioning (P = 0.024, Cohen's d = 0.77), and post-HIIT (P = 0.014, Cohen's d = 0.90). Results of this study provide preliminary evidence that HIIT preceded by preconditioning can induce small improvements in fasting insulin, glucose, and HOMA1-IR in sedentary older men compared with masters athletes. © 2020 Elsevier Inc.
- Publisher
- Elsevier Inc.
- Relation
- Experimental Gerontology Vol. 140, no. (2020), p.
- Rights
- Copyright © 2020 Elsevier Inc. All rights reserved
- Rights
- This metadata is freely available under a CCO license
- Subject
- 11 Medical and Health Sciences; Aging; Exercise; Glucose; HIIT; Insulin; Masters athletes; Sedentary
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