The effect of a single bout of high-intensity sprint exercise programme compared to traditional high-intensity sprint interval exercise and endurance exercise on inflammatory markers, lipid profile and health-related physical fitness measurements in participants with elevated cardiovascular disease risk
Date
2021
Authors
Rugbeer, Nivash
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Abstract
Background: A sedentary lifestyle increases the risk of cardiovascular disease (CVD). Inactivity is a global burden, and escalating work and family commitments directly impact exercise adherence. The study aimed to compare the effect of the novel time-efficient ‘Gear’ exercise programme (90-second ‘Gear’ exercise programme) repeated at different times in the day (GEP-DT) and the effect of the 18-minute ‘Gear’ exercise programme repeated at one point in time (GEP-OT) with traditional exercise on cardiometabolic risk factors, inflammatory markers and cardiorespiratory fitness (CRF) measurements in sedentary persons with an elevated risk of CVD. The study addressed the aims and objectives in two published studies (study 1 and study 3) and two studies that are under review for publication in international journals (study 2 and study 4). Study 1 is a meta-analysis and systematic review comparing the effect of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) and sprint interval training (SIT) versus MICT on CRF and body fat percentage in overweight or obese persons. Study 2 investigated the association between CRF measurements, cardiometabolic risk factors and inflammatory markers in overweight or obese persons. Study 3 investigated the effect of the GEP-DT and GEP-OT on cardiometabolic risk factors in persons with an elevated risk of CVD. Study 4 investigated the effect of the GEP-DT and GEP-OT on markers of inflammation and CRF in persons at risk of CVD.
Methods: Study 1 entailed a systematic search of randomised controlled trials (RCTs) using the health science databases that occurred up to April 2020. Twenty-six studies were included for complete analysis. A total of 784 participations were analysed. The unstandardised mean difference for each outcome measurement was extracted from the studies and pooled with the random-effects model.
Study 2 adopted a cross-sectional design. Eighty-two participants from the university participated in the study. The outcome measurements were inflammatory markers, CRF measurements, cardiometabolic risk factors and the Framingham risk score.
Study 3 implemented a six-week, RCT. The outcome variables were low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides (TG), total cholesterol, glycated haemoglobin (HbA1c), blood pressure and body composition. Forty-eight participants completed the study. Participants were randomly assigned to either the GEP-DT: cycled for 90 seconds, repeated three times per day, for three days per week (n = 12); GEP-OT: cycled for 90 seconds followed by four minutes and 30 seconds rest, repeated three times at one point in time, for three days per week (n = 14); 30 minutes of moderate-intensity continuous cycling repeated three days per week at 55-69% HRmax (n = 11); and the controls (CTRL), who were encouraged not to exercise (n = 11).
Study 4 adopted a RCT. Forty-eight participants completed the study. The outcome variables were high-sensitivity C-reactive protein, erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6), peak oxygen consumption (VO2peak) and ventilatory threshold measurements (health-related CRF measurements). Participants were randomly assigned to either the GEP-DT: cycled for 90 seconds, repeated three times/day, for three days per week (n = 12); the GEP-OT: cycled for 90 seconds followed by four minutes and 30 seconds rest, repeated three times at one point in time, for three days per week (n = 14); 30 minutes of moderate-intensity continuous cycling repeated three days per week at 55-69% HRmax (n = 11); and the controls, who were encouraged not to exercise (n = 11).
Results: Study 1: MICT was significantly better at improving CRF compared with sprint interval training (SIT) (MD = −0.92; 95% CI = -1.63 to −0.21; p = 0.01; I2 = 10%). There was no significant difference between MICT versus HIIT on CRF (MD = −0.52; 95% CI = −1.18 to 0.13; p = 0.12; I2 = 23%). There was no significant difference in body fat percentage between MICT versus HIIT and MICT versus SIT.
Study 2: A moderate, negative correlation was found between HbA1c and load at ventilatory threshold (VT-L) (Rs = −0.441; p<0.001). Moreover, there was a positive correlation between ESR and body fat percentage (Rs = 0.438; p<0.001). Multiple linear regression showed that VO2peak was inversely related to age (β = −0.007; p = 0.048). VT-L was significantly inversely related to HbA1c (β = −0.089; p = 0.001). For every one-unit increase in the VT-L, HbA1c decreased by 9.31%.
Study 3: The 90-second GEP-DT intervention reduced HbA1c, post six- weeks of training, with a moderate effect size (MD = −0.1±0.4; % Δ = −1.3%; d = −0.70; d (95% CI): −1.55, 0.14). The GEP-OT group demonstrated a decrease in TG post-training with a large effect size (MD = −0.6±1.3; % Δ = −31.9%; d = −0.83; d (95% CI): −1.68, 0.01). The GEP-OT group decreased blood TG with a large effect size (MD = −0.6±1.3; % Δ = −31.9%; d = −0.83). The MICE group demonstrated a large effect size for diastolic blood pressure (DBP), which showed a significant reduction in DBP post-training (MD = −5.4±3.8; % Δ = -6.8%; d = −0.81; d (95% CI): −1.68, 0.06). This group also demonstrated a large effect size for body fat percentage, which showed a significant reduction in body fat percentage post-training (MD = −0.7±2.1; % Δ = −2.5; d = −0.83; d (95% CI): −1.70, 0.04).
Study 4: The 90-second GEP-DT demonstrated a moderate increase in VT-L (MD = 8.18±12.30; % Δ = 14.53; d = 0.77; d (95% CI): −0.17, 1.64), VO2peak at ventilatory threshold (MD = 2.93±6.08; % Δ = 53.76; d = 0.66; d (95% CI): −0.18, 1.50) and metabolic equivalent at ventilatory threshold (MD = 0.83±1.76; % Δ = 52.23; d =0.65; d (95% CI): −0.19, 1.49). The GEP-OT group demonstrated a large effect size for VT-L (MD = 11.79±18.77; % Δ = 18.86; d = 0.81; d (95% CI): −0.02, 1.63). Furthermore, this group demonstrated a moderate effect size for VO2peak at ventilatory threshold (MD = 3.59±6.73; % Δ = 50.21; d = 0.72; d (95% CI): −0.10, 1.53), ventilatory equivalent at ventilatory threshold (MD = 8.05±14.66; % Δ = 44.65; d = 0.63; d (95% CI): −0.18, 1.44) and metabolic equivalent at ventilatory threshold (MD = 1.03±1.91; % Δ = 50.49; d = 0.72; d (95% CI): −0.09, 1.54). The 18-minute GEP-OT group demonstrated a substantial decrease in IL-6 post six-weeks of training (% Δ = −77.27); however, the probability value was insignificant.
Conclusions: MICT was significantly better at improving CRF when compared to SIT in overweight or obese persons. ). For every one-unit increase in the VT-L, HbA1c decreased by 9.31%. The novel 90-second ‘Gear’ exercise programme moderately reduced HbA1c, and the 18-minute GEP-OT lowered blood TG. MICE decreased DBP and body fat percentage. ‘Gear’ exercise programmes raised the ventilatory threshold point, which prevented premature fatigue and improved the efficiency of the cardiorespiratory system. Gear’ exercise programmes will encourage future research in persons with NCD, and it should be considered as a public health initiative to promote exercise in clinical, home and work environments because it is a time-efficient exercise intervention.
Description
A Thesis submitted to the Faculty of Health Sciences, in fulfilment of the requirements for the degree of Doctor of Philosophy in the field of Therapeutic Sciences, University of the Witwatersrand, Johannesburg, 2021.