Six weeks of high intensity interval training (HIIT) facilitates a four year preservation of aerobic capacity in sedentary older males : a reunion study
- Authors: Herbert, Peter , Hayes, Lawrence , Beaumont, Alexander , Grace, Fergal , Sculthorpe, Nicholas
- Date: 2021
- Type: Text , Journal article
- Relation: Experimental Gerontology Vol. 150, no. (2021), p.
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- Description: Long-term implications of acutely increased cardiorespiratory fitness following short-term exercise interventions in older adults are unknown. In this study, we examined peak oxygen uptake (VO2peak) after 4-years of ‘free-living’ after a high intensity interval training (HIIT) intervention. Seventeen lifelong exercisers (LEX) and 17 previously sedentary (SED) males (55–74 years of age in 2012) were tested four years (phase D) after our previous experiment which included 6-weeks of aerobic moderate intensity exercise (phase B), followed by 6-weeks of HIIT (phase C). At all stages, a standard incremental exercise protocol on a cycle ergometer was completed to determine VO2peak. SED (P = 1.000, Cohen's d = 0.01) and LEX (P = 1.000, Cohen's d = 0.11) VO2peak at phase D was not different from phase A (enrolment). SED experienced a large decrease in VO2peak from phase C to phase D (32 ± 6 ml·kg·min−1 to 27 ± 6 ml·kg·min−1 [P < 0.001, Cohen's d = 0.81]). LEX experienced a small decrease in VO2peak from phase C to phase D (42 ± 7 ml·kg·min−1 to 39 ± 9 ml·kg·min−1 [P < 0.001, Cohen's d = 0.46]). At phase D, LEX had greater VO2peak than SED (P < 0.001, Cohen's d = 1.73). The proportion of subjects who reported discontinuing training, maintaining moderate training, and maintaining HIIT differed between groups (P = 0.023), with LEX self-reporting more HIIT, and SED self-reporting more discontinuation from exercise. Those who continued exercising experienced a reduction in VO2peak over the four years from 39 ± 7 ml·kg·min−1 to 36 ± 9 ml·kg·min−1 (N = 25, P < 0.001, Cohen's d = 0.37), and those who discontinued exercising also experienced a reduction in VO2peak from 30 ± 7 ml·kg·min−1 to 25 ± 9 ml·kg·min−1 (N = 9, P = 0.003, Cohen's d = 0.62). Four years after completing a brief period of aerobic exercise and HIIT, older males demonstrated a preservation of VO2peak, irrespective of training status (LEX or SED). However, LEX exhibited greater VO2peak than SED after 4-years of unsupervised ‘free-living’. Notably, participants who discontinued exercising experienced a greater reduction in VO2peak. These data suggest that a 6 weeks of supervised HIIT can facilitate the long term. © 2021 Elsevier Inc.
High intensity interval training (HIIT) produces small improvements in fasting glucose, insulin, and insulin resistance in sedentary older men but not masters athletes
- Authors: Hayes, Lawrence , Herbert, Peter , Sculthorpe, Nicholas , Grace, Fergal
- Date: 2020
- Type: Text , Journal article
- Relation: Experimental Gerontology Vol. 140, no. (2020), p.
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- Description: 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.
High intensity interval training (HIIT) improves resting blood pressure, metabolic (MET) capacity and heart rate reserve without compromising resting myocardial function in sedentary aging men
- Authors: Grace, Fergal , Herbert, Peter , Elliott, Adrian , Beaumont, Alexander , Richards, Jo , Sculthorpe, Nicholas
- Date: 2017
- Type: Text , Journal article
- Relation: Experimental Gerontology Vol.109, no. (2018), p.75-81
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- Description: Background This study examined a programme of pre-conditioning exercise with subsequent high intensity interval training (HIIT) on blood pressure, echocardiography, cardiac strain mechanics and maximal metabolic (MET) capacity in sedentary (SED) aging men compared with age matched masters athletes (LEX). Methods Using a STROBE compliant observational design, 39 aging male participants (SED; n = 22, aged 62.7 ± 5.2 yrs) (LEX; n = 17, aged = 61.1 ± 5.4 yrs) were recruited to a study that necessitated three distinct assessment phases; enrolment (Phase A), following pre-conditioning exercise in SED (Phase B), then following 6 weeks of HIIT performed once every five days by both groups before reassessment (Phase C). Hemodynamic, echocardiographic and cardiac strain mechanics were obtained at rest and maximal cardiorespiratory and chronotropic responses were obtained at each measurement phase. Results The training intervention improved systolic, mean arterial blood pressure, rate pressure product and heart rate reserve (each P < 0.05) in SED and increased MET capacity in both SED and LEX (P < 0.01) which was amplified by HIIT. Echocardiography and cardiac strain measures were unremarkable apart from trivial increase to intra-ventricular septum diastole (IVSd) (P < 0.05) and decrease to left ventricular internal dimension diastole (LVId) (P < 0.05) in LEX following HIIT. Conclusions A programme of preconditioning exercise with HIIT induces clinically relevant improvements in blood pressure, rate pressure product and encourages recovery of heart rate reserve in SED, while improving maximal MET capacity in both SED and LEX without inducing any pathological cardiovascular remodeling. These data add to the emerging repute of HIIT as a safe and promising exercise prescription to improve cardiovascular function and metabolic capacity in sedentary aging.
A commentary on "Testosterone and cortisol jointly modulate risk-taking" by P.H. Mehta, K.M. Welker, S. Zilioli, J.M. Carre, Psychoneuroendocrinology, 2015, 56, 88-99
- Authors: Hayes, Lawrence , Sculthorpe, Nicholas , Grace, Fergal
- Date: 2016
- Type: Text , Journal article
- Relation: Psychoneuroendocrinology Vol. 63, no. (2016), p. 380-381
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Acute whole body UVA irradiation combined with nitrate ingestion enhances time trial performance in trained cyclists
- Authors: Muggeridge, David , Sculthorpe, Nicholas , Grace, Fergal , Willis, Gareth , Thornhill, Laurence , Weller, Richard , James, Philip , Easton, Chris
- Date: 2015
- Type: Text , Journal article
- Relation: Nitric Oxide : Biology and Chemistry Vol. 48, no. (2015), p. 3-9
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- Description: Dietary nitrate supplementation has been shown to increase nitric oxide (NO) metabolites, reduce blood pressure (BP) and enhance exercise performance. Acute exposure to ultraviolet (UV)-A light also increases NO bioavailability and reduces BP. We conducted a randomized, counterbalanced placebo-controlled trial to determine the effects of UV-A light alone and in combination with nitrate on the responses to sub-maximal steady-state exercise and time trial (TT) performance. Nine cyclists (VO2max 53.1 +/- 4.4 ml/kg/min) completed five performance trials comprising 10 min submaximal steady-state cycling followed by a 16.1 km TT. Following a familiarization the final four trials were preceded, in random order, by either (1) Nitrate gels (NIT) + UV-A, (2) Placebo (PLA) + UV-A, (3) NIT + Sham light (SHAM) and (4) PLA + SHAM (control). The NIT gels (2 x 60 ml gels, ~8.1 mmol nitrate) or a low-nitrate PLA were ingested 2.5 h prior to the trial. The light exposure consisted of 20 J/cm(2) whole body irradiation with either UV-A or SHAM light. Plasma nitrite was measured pre- and post-irradiation and VO2 was measured continuously during steady-state exercise. Plasma nitrite was higher for NIT + SHAM (geometric mean (95% CI), 332 (292-377) nM; P = 0.029) and NIT + UV-A (456 (312-666) nM; P = 0.014) compared to PLA + SHAM (215 (167-277) nM). Differences between PLA + SHAM and PLA + UV-A (282 (248-356) nM) were small and non-significant. During steady-state exercise VO2 was reduced following NIT + UVA (P = 0.034) and tended to be lower in NIT + SHAM (P = 0.086) but not PLA + UV-A (P = 0.381) compared to PLA + SHAM. Performance in the TT was significantly faster following NIT + UV-A (mean +/- SD 1447 +/- 41 s P = 0.005; d = 0.47), but not PLA + UV-A (1450 +/- 40 s; d = 0.41) or NIT + SHAM (1455 +/- 47 s; d = 0.28) compared to PLA + SHAM (1469 +/- 52 s). These findings demonstrate that exposure to UV-A light alone does not alter the physiological responses to exercise or improve performance in a laboratory setting. A combination of UV-A and NIT, however, does improve cycling TT performance in this environment, which may be due to a larger increase in NO availability.
Impact of low-volume, high-intensity interval training on maximal aerobic capacity, health-related quality of life and motivation to exercise in ageing men
- Authors: Knowles, Ann-Marie , Herbert, Peter , Easton, Chris , Sculthorpe, Nicholas , Grace, Fergal
- Date: 2015
- Type: Text , Journal article
- Relation: Age Vol. 37, no. 2 (2015), p. 25
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- Description: There is a demand for effective training methods that encourage exercise adherence during advancing age, particularly in sedentary populations. This study examined the effects of high-intensity interval training (HIIT) exercise on health-related quality of life (HRQL), aerobic fitness and motivation to exercise in ageing men. Participants consisted of males who were either lifelong sedentary (SED; N = 25; age 63 +/- 5 years) or lifelong exercisers (LEX; N = 19; aged 61 +/- 5 years). [Formula: see text] and HRQL were measured at three phases: baseline (Phase A), week seven (Phase B) and week 13 (Phase C). Motivation to exercise was measured at baseline and week 13. [Formula: see text] was significantly higher in LEX (39.2 +/- 5.6 ml kg min(-1)) compared to SED (27.2 +/- 5.2 ml kg min(-1)) and increased in both groups from Phase A to C (SED 4.6 +/- 3.2 ml kg min(-1), 95 % CI 3.1 - 6.0; LEX 4.9 +/- 3.4 ml kg min(-1), 95 % CI 3.1-6.6) Physical functioning (97 +/- 4 LEX; 93 +/- 7 SED) and general health (70 +/- 11 LEX; 78 +/- 11 SED) were significantly higher in LEX but increased only in the SED group from Phase A to C (physical functioning 17 +/- 18, 95 % CI 9-26, general health 14 +/- 14, 95 % CI 8-21). Exercise motives related to social recognition (2.4 +/- 1.2 LEX; 1.5 +/- 1.0 SED), affiliation (2.7 +/- 1.0 LEX; 1.6 +/- 1.2 SED) and competition (3.3 +/- 1.3 LEX; 2.2 +/- 1.1) were significantly higher in LEX yet weight management motives were significantly higher in SED (2.9 +/- 1.1 LEX; 4.3 +/- 0.5 SED). The study provides preliminary evidence that low-volume HIIT increases perceptions of HRQL, exercise motives and aerobic capacity in older adults, to varying degrees, in both SED and LEX groups.
The effect of short-term creatine loading on active range of movement
- Authors: Sculthorpe, Nicholas , Grace, Fergal , Jones, Peter , Fletcher, Iain
- Date: 2010
- Type: Text , Journal article
- Relation: Applied Physiology, Nutrition, and Metabolism Vol. 35, no. 4 (2010), p. 507-511
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- Description: During high-intensity exercise, intracellular creatine phosphate (PCr) is rapidly broken down to maintain adenosine triphosphate turnover. This has lead to the widespread use of creatine monohydrate as a nutritional ergogenic aid. However, the increase in intracellular PCr and the concomitant increase in intracellular water have not been investigated with regard to their effect on active range of movement (ROM). Forty male subjects (age, 24+/-3.2 years) underwent restricted randomization into 2 equal groups, either an intervention group (CS) or a control group (C). The CS group ingested 25 g.day(-1) of creatine monohydrate for 5 days, followed by 5 g.day(-1) for a further 3 days. Before (24 h before starting supplementation (PRE) and after (on the 8th day of supplementation (POST)) this loading phase, both groups underwent goniometry measurement of the shoulder, elbow, hip, and ankle. Data indicated significant reductions in active ROM in 3 movements: shoulder extension (57+/-11.3 degrees PRE vs. 48+/-11.2 degrees POST, p<0.01), shoulder abduction (183.4+/-6.8 degrees PRE vs. 180.3+/-5.1 degrees POST, p<0.05), and ankle dorsiflexion (14.2+/-4.7 degrees PRE vs. 12.1+/-6.4 degrees POST, p<0.01). There was also a significant increase in body mass for the CS group (83.6+/-6.2 kg vs. 85.2+/-6.3 kg, p<0.05). The results suggest that short-term supplementation with creatine monohydrate reduces the active ROM of shoulder extension and abduction and of ankle dorsiflexion. Although the mechanism for this is not fully understood, it may be related to the asymmetrical distribution of muscle mass around those joints.