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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.


Related in: MedlinePlus

Distance covered and average power output during the performance trial. Figure 4 shows the distance covered and average power output elicited during the 40 minute performance trial for both treatment conditions at week 0, 2 and 4 of the intervention. Data are presented as mean ± SE. PL, Placebo; dGTE, decaffeinated green tea extract. Adenotes significant overall group × time interaction effect (P ≤ 0.001). Bdenotes significant overall time interaction effect (P < 0.001). 1denotes significant within group time interaction effect only (P = 0.039). *denotes significant difference (P ≤ 0.02) to baseline only within group. #denotes significant difference to week 2 within group only (P = 0.03).
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Fig4: Distance covered and average power output during the performance trial. Figure 4 shows the distance covered and average power output elicited during the 40 minute performance trial for both treatment conditions at week 0, 2 and 4 of the intervention. Data are presented as mean ± SE. PL, Placebo; dGTE, decaffeinated green tea extract. Adenotes significant overall group × time interaction effect (P ≤ 0.001). Bdenotes significant overall time interaction effect (P < 0.001). 1denotes significant within group time interaction effect only (P = 0.039). *denotes significant difference (P ≤ 0.02) to baseline only within group. #denotes significant difference to week 2 within group only (P = 0.03).

Mentions: A significant overall group × time interaction was found for distance covered (F = 9.84, P = 0.001; Figure 4). The use of dGTE resulted in a progressive increase in distance covered from 20.23 ± 0.54 km at week 0, to 21.77 ± 0.49 km at week 2 and finally 22.43 ± 0.40 km by week 4, representing a 10.9% significant increase in performance (F = 28.66, P < 0.001; ηp2 = 0.85). A similar interaction effect was also observed for PL (F = 7.94, P = 0.009; ηp2 = 0.61) with distance covered significantly improving by week 2 (21.75 ± 0.40 km) compared to week 0 (20.79 ± 0.30 km; P = 0.002) only.Figure 4


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)

Distance covered and average power output during the performance trial. Figure 4 shows the distance covered and average power output elicited during the 40 minute performance trial for both treatment conditions at week 0, 2 and 4 of the intervention. Data are presented as mean ± SE. PL, Placebo; dGTE, decaffeinated green tea extract. Adenotes significant overall group × time interaction effect (P ≤ 0.001). Bdenotes significant overall time interaction effect (P < 0.001). 1denotes significant within group time interaction effect only (P = 0.039). *denotes significant difference (P ≤ 0.02) to baseline only within group. #denotes significant difference to week 2 within group only (P = 0.03).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig4: Distance covered and average power output during the performance trial. Figure 4 shows the distance covered and average power output elicited during the 40 minute performance trial for both treatment conditions at week 0, 2 and 4 of the intervention. Data are presented as mean ± SE. PL, Placebo; dGTE, decaffeinated green tea extract. Adenotes significant overall group × time interaction effect (P ≤ 0.001). Bdenotes significant overall time interaction effect (P < 0.001). 1denotes significant within group time interaction effect only (P = 0.039). *denotes significant difference (P ≤ 0.02) to baseline only within group. #denotes significant difference to week 2 within group only (P = 0.03).
Mentions: A significant overall group × time interaction was found for distance covered (F = 9.84, P = 0.001; Figure 4). The use of dGTE resulted in a progressive increase in distance covered from 20.23 ± 0.54 km at week 0, to 21.77 ± 0.49 km at week 2 and finally 22.43 ± 0.40 km by week 4, representing a 10.9% significant increase in performance (F = 28.66, P < 0.001; ηp2 = 0.85). A similar interaction effect was also observed for PL (F = 7.94, P = 0.009; ηp2 = 0.61) with distance covered significantly improving by week 2 (21.75 ± 0.40 km) compared to week 0 (20.79 ± 0.30 km; P = 0.002) only.Figure 4

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.


Related in: MedlinePlus