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The effect of a decaffeinated green tea extract formula on fat oxidation, body composition and exercise performance.

Roberts JD, Roberts MG, Tarpey MD, Weekes JC, Thomas CH - J Int Soc Sports Nutr (2015)

Bottom Line: Body fat significantly decreased with dGTE by 1.63 ± 0.16% in contrast to PL over the intervention period (P < 0.001; ηp(2) = 0.84).No significant changes for FFA or blood pressure between groups were observed. dGTE resulted in a 10.9% improvement in performance distance covered from 20.23 ± 0.54 km to 22.43 ± 0.40 km by week 4 (P < 0.001; ηp(2) = 0.85).A 4 week dGTE intervention favourably enhanced substrate utilisation and subsequent performance indices, but did not alter TFA concentrations in comparison to PL.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences, Anglia Ruskin University, East Road, Cambridge, UK ; School of Life & Medical Sciences, University of Hertfordshire, College Lane, Hatfield, Hertfordshire UK.

ABSTRACT

Background: The cardio-metabolic and antioxidant health benefits of caffeinated green tea (GT) relate to its catechin polyphenol content. Less is known about decaffeinated extracts, particularly in combination with exercise. The aim of this study was therefore to determine whether a decaffeinated green tea extract (dGTE) positively influenced fat oxidation, body composition and exercise performance in recreationally active participants.

Methods: Fourteen, recreationally active males participated in a double-blind, placebo-controlled, parallel design intervention (mean ± SE; age = 21.4 ± 0.3 yrs; weight = 76.37 ± 1.73 kg; body fat = 16.84 ± 0.97%, peak oxygen consumption [[Formula: see text]] = 3.00 ± 0.10 L·min(-1)). Participants were randomly assigned capsulated dGTE (571 mg·d(-1); n = 7) or placebo (PL; n = 7) for 4 weeks. Following body composition and resting cardiovascular measures, participants cycled for 1 hour at 50% [Formula: see text], followed by a 40 minute performance trial at week 0, 2 and 4. Fat and carbohydrate oxidation was assessed via indirect calorimetry. Pre-post exercise blood samples were collected for determination of total fatty acids (TFA). Distance covered (km) and average power output (W) were assessed as exercise performance criteria.

Results: Total fat oxidation rates increased by 24.9% from 0.241 ± 0.025 to 0.301 ± 0.009 g·min(-1) with dGTE (P = 0.05; ηp(2) = 0.45) by week 4, whereas substrate utilisation was unaltered with PL. Body fat significantly decreased with dGTE by 1.63 ± 0.16% in contrast to PL over the intervention period (P < 0.001; ηp(2) = 0.84). No significant changes for FFA or blood pressure between groups were observed. dGTE resulted in a 10.9% improvement in performance distance covered from 20.23 ± 0.54 km to 22.43 ± 0.40 km by week 4 (P < 0.001; ηp(2) = 0.85).

Conclusions: A 4 week dGTE intervention favourably enhanced substrate utilisation and subsequent performance indices, but did not alter TFA concentrations in comparison to PL. The results support the use of catechin polyphenols from dGTE in combination with exercise training in recreationally active volunteers.

No MeSH data available.


Weekly contribution of substrate to total energy expenditure (EE) for the dGTE group. Figure 2 shows the contribution of both fat and carbohydrate (based on oxidation rates) to energy expenditure during submaximal exercise for the dGTE condition. Data are presented as mean ± SE. dGTE, decaffeinated green tea extract; FAT, average fat oxidation rates; CHO, average carbohydrate oxidation rates. Adenotes significant overall group × time interaction effect compared with PL (Figure 1; P = 0.05). Bdenotes significant overall time interaction effect in conjunction with PL (Figure 1; P ≤ 0.03). 1 denotes significant interaction over time within GTE only (P ≤ 0.05).
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Fig2: Weekly contribution of substrate to total energy expenditure (EE) for the dGTE group. Figure 2 shows the contribution of both fat and carbohydrate (based on oxidation rates) to energy expenditure during submaximal exercise for the dGTE condition. Data are presented as mean ± SE. dGTE, decaffeinated green tea extract; FAT, average fat oxidation rates; CHO, average carbohydrate oxidation rates. Adenotes significant overall group × time interaction effect compared with PL (Figure 1; P = 0.05). Bdenotes significant overall time interaction effect in conjunction with PL (Figure 1; P ≤ 0.03). 1 denotes significant interaction over time within GTE only (P ≤ 0.05).

Mentions: Weekly contribution of substrate to total energy expenditure (EE) for PL and dGTE are reported in Figures 1 and 2 respectively. No significant differences were reported for EE either between or within groups over time (P > 0.05), demonstrating consistency of the submaximal exercise trials.Figure 1


The effect of a decaffeinated green tea extract formula on fat oxidation, body composition and exercise performance.

Roberts JD, Roberts MG, Tarpey MD, Weekes JC, Thomas CH - J Int Soc Sports Nutr (2015)

Weekly contribution of substrate to total energy expenditure (EE) for the dGTE group. Figure 2 shows the contribution of both fat and carbohydrate (based on oxidation rates) to energy expenditure during submaximal exercise for the dGTE condition. Data are presented as mean ± SE. dGTE, decaffeinated green tea extract; FAT, average fat oxidation rates; CHO, average carbohydrate oxidation rates. Adenotes significant overall group × time interaction effect compared with PL (Figure 1; P = 0.05). Bdenotes significant overall time interaction effect in conjunction with PL (Figure 1; P ≤ 0.03). 1 denotes significant interaction over time within GTE only (P ≤ 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4307170&req=5

Fig2: Weekly contribution of substrate to total energy expenditure (EE) for the dGTE group. Figure 2 shows the contribution of both fat and carbohydrate (based on oxidation rates) to energy expenditure during submaximal exercise for the dGTE condition. Data are presented as mean ± SE. dGTE, decaffeinated green tea extract; FAT, average fat oxidation rates; CHO, average carbohydrate oxidation rates. Adenotes significant overall group × time interaction effect compared with PL (Figure 1; P = 0.05). Bdenotes significant overall time interaction effect in conjunction with PL (Figure 1; P ≤ 0.03). 1 denotes significant interaction over time within GTE only (P ≤ 0.05).
Mentions: Weekly contribution of substrate to total energy expenditure (EE) for PL and dGTE are reported in Figures 1 and 2 respectively. No significant differences were reported for EE either between or within groups over time (P > 0.05), demonstrating consistency of the submaximal exercise trials.Figure 1

Bottom Line: Body fat significantly decreased with dGTE by 1.63 ± 0.16% in contrast to PL over the intervention period (P < 0.001; ηp(2) = 0.84).No significant changes for FFA or blood pressure between groups were observed. dGTE resulted in a 10.9% improvement in performance distance covered from 20.23 ± 0.54 km to 22.43 ± 0.40 km by week 4 (P < 0.001; ηp(2) = 0.85).A 4 week dGTE intervention favourably enhanced substrate utilisation and subsequent performance indices, but did not alter TFA concentrations in comparison to PL.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences, Anglia Ruskin University, East Road, Cambridge, UK ; School of Life & Medical Sciences, University of Hertfordshire, College Lane, Hatfield, Hertfordshire UK.

ABSTRACT

Background: The cardio-metabolic and antioxidant health benefits of caffeinated green tea (GT) relate to its catechin polyphenol content. Less is known about decaffeinated extracts, particularly in combination with exercise. The aim of this study was therefore to determine whether a decaffeinated green tea extract (dGTE) positively influenced fat oxidation, body composition and exercise performance in recreationally active participants.

Methods: Fourteen, recreationally active males participated in a double-blind, placebo-controlled, parallel design intervention (mean ± SE; age = 21.4 ± 0.3 yrs; weight = 76.37 ± 1.73 kg; body fat = 16.84 ± 0.97%, peak oxygen consumption [[Formula: see text]] = 3.00 ± 0.10 L·min(-1)). Participants were randomly assigned capsulated dGTE (571 mg·d(-1); n = 7) or placebo (PL; n = 7) for 4 weeks. Following body composition and resting cardiovascular measures, participants cycled for 1 hour at 50% [Formula: see text], followed by a 40 minute performance trial at week 0, 2 and 4. Fat and carbohydrate oxidation was assessed via indirect calorimetry. Pre-post exercise blood samples were collected for determination of total fatty acids (TFA). Distance covered (km) and average power output (W) were assessed as exercise performance criteria.

Results: Total fat oxidation rates increased by 24.9% from 0.241 ± 0.025 to 0.301 ± 0.009 g·min(-1) with dGTE (P = 0.05; ηp(2) = 0.45) by week 4, whereas substrate utilisation was unaltered with PL. Body fat significantly decreased with dGTE by 1.63 ± 0.16% in contrast to PL over the intervention period (P < 0.001; ηp(2) = 0.84). No significant changes for FFA or blood pressure between groups were observed. dGTE resulted in a 10.9% improvement in performance distance covered from 20.23 ± 0.54 km to 22.43 ± 0.40 km by week 4 (P < 0.001; ηp(2) = 0.85).

Conclusions: A 4 week dGTE intervention favourably enhanced substrate utilisation and subsequent performance indices, but did not alter TFA concentrations in comparison to PL. The results support the use of catechin polyphenols from dGTE in combination with exercise training in recreationally active volunteers.

No MeSH data available.