Intake of the catechin epigallocatechin gallate and caffeine has been shown to enhance exercise-induced fat oxidation. Matcha green tea powder contains catechins and caffeine and is consumed as a drink. We examined the effect of Matcha green tea drinks on metabolic, physiological, and perceived intensity responses during brisk walking. A total of 13 females (age: 27 ± 8 years, body mass: 65 ± 7 kg, height: 166 ± 6 cm) volunteered to participate in the study. Resting metabolic equivalent (1-MET) was measured using Douglas bags (1-MET: 3.4 ± 0.3 ml·kg⁻¹·min⁻¹). Participants completed an incremental walking protocol to establish the relationship between walking speed and oxygen uptake and individualize the walking speed at 5- or 6-MET. A randomized, crossover design was used with participants tested between Days 9 and 11 of the menstrual cycle (follicular phase). Participants consumed three drinks (each drink made with 1 g of Matcha premium grade; OMGTea Ltd., Brighton, UK) the day before and one drink 2 hr before the 30-min walk at 5- (n = 10) or 6-MET (walking speed: 5.8 ± 0.4 km/hr) with responses measured at 8–10, 18–20, and 28–30 min. Matcha had no effect on physiological and perceived intensity responses. Matcha resulted in lower respiratory exchange ratio (control: 0.84 ± 0.04; Matcha: 0.82 ± 0.04; p < .01) and enhanced fat oxidation during a 30-min brisk walk (control: 0.31 ± 0.10; Matcha: 0.35 ± 0.11 g/min; p < .01). Matcha green tea drinking can enhance exercise-induced fat oxidation in females. However, when regular brisk walking with 30-min bouts is being undertaken as part of a weight loss program, the metabolic effects of Matcha should not be overstated.

Anthocyanin supplements are receiving attention due to purported benefits to physiological, metabolic, and exercise responses in trained individuals. However, the efficacy of anthocyanin intake over multiple testing days is not known. We compared a placebo and two doses of anthocyanin-rich New Zealand blackcurrant (NZBC) extract (300 and 600 mg·day⁻¹) on plasma lactate, substrate oxidation, and 16.1 km time trial (TT) performance on three occasions over 7-days in a fed state (day 1 (D1), D4, and D7). Thirteen male cyclists participated in a randomized, crossover, placebo-controlled double-blind design. There was no difference in plasma lactate and substrate oxidation between conditions and between days. A time difference was observed between D1 (1701 ± 163 s) and D4 (1682 ± 162 s) for 600 mg (p = 0.05), with an increment in average speed (D1 = 34.3 ± 3.4 vs. D4 = 34.8 ± 3.4 km·h⁻¹, p = 0.04). However, there was no difference between the other days and between conditions. Overall, one week of intake of NZBC extract did not affect physiological and metabolic responses. Intake of 600 mg of NZBC extract showed inconsistent benefits in improving 16.1 km time trial performance over a week period in trained fed cyclists.

We examined effects of intake duration of anthocyanin-rich New Zealand blackcurrant (NZBC) extract on physiological and metabolic responses during moderate intensity walking. Healthy men (n = 16, age: 24 ± 6 years, body mass: 78 ± 16 kg, BMI: 24.7 ± 4.1 kg·m⁻², body fat: 15 ± 5%) volunteered. One metabolic equivalent (1-MET: 3.95 ± 0.64 ml·kg⁻¹·min⁻¹) was measured during supine rest. Responses during the 30-min walk (n = 3: 4-MET; n = 13: 5-MET) (speed: 5.7 ± 0.7 km·hr⁻¹) were measured at 7-10, 17-20 and 27-30 min and averaged over the time periods. For intake conditions (7-days and 14-days), two capsules of NZBC extract (600 mg containing 210 mg of anthocyanins) were taken with breakfast (14-day washout). The final two capsules were ingested 2-hr before the morning walk. Intake duration of NZBC extract had no effect on heart rate, minute ventilation, oxygen uptake, and carbon dioxide production. Fat oxidation was enhanced with 7- and 14-day intake by 11 ± 19% and 17 ± 26% (baseline: 0.36 ± 0.12, 7-day: 0.39 ± 0.13, 14-day: 0.41 ± 0.13 g·min⁻¹, p = 0.007). Only 14-day intake lowered RER (baseline: 0.852 ± 0.046, 7-day: 0.843 ± 0.045, 14-day: 0.837 ± 0.037, p = 0.019) and carbohydrate oxidation (baseline: 0.95 ± 0.40, 7-day: 0.91 ± 0.40, 14-day: 0.86 ± 0.33 g·min⁻¹, p = 0.032). Rating of perceived exertion was lower with 7-day and 14-day intake (baseline: 11.0 ± 2.3, 7-day: 10.5 ± 1.8, 14-day: 10.3 ± 2.1, p = 0.002). Longer intake duration (i.e. 14 days) of New Zealand blackcurrant extract seems to enhance fat oxidation more during a 30-min moderate intensity walk than 7 days intake. The intake duration of anthocyanin-rich New Zealand blackcurrant extract may be due to an enhanced bioavailability of anthocyanin-derived metabolites that alter the mechanisms for substrate oxidation during moderate intensity exercise.

New Zealand blackcurrant (NZBC) extract enhanced exercise-induced fat oxidation and 16.1 km cycling time trial (TT) in normobaric normoxia. The effect of NZBC extract on physiological and metabolic responses was examined during steady state cycling and a 16.1 km TT in normobaric hypoxia. This study used a randomized, double-blind, crossover design. Eleven healthy male cyclists (age: 38 ± 11 y, height: 179 ± 4 cm, body mass: 76 ± 8 kg, $\dot{V}$ O_2max: 47 ± 5 mL·kg⁻¹·min⁻¹, mean ± SD) ingested NZBC extract (600 mg·day⁻¹ CurraNZ® containing 210 mg anthocyanins) or a placebo (600 mg microcrystalline cellulose M102) for seven days (washout 14 days) and performed a steady state cycling test (3 × 10 min at 45%, 55% and 65% $\dot{V}$ O_2max) followed by a 16.1 km TT at a simulated altitude of ~2500 meters (~15% of O₂). Indirect calorimetry was used to measure substrate oxidation during steady state cycling. Intake of NZBC extract had no effect on blood glucose and lactate, heart rate, substrate oxidation, and respiratory exchange ratio during steady state cycling at 45%, 55% and 65% $\dot{V}$ O_2max, and on 16.1 km TT performance (placebo: 1685 ± 92 s, NZBC extract: 1685 ± 99 s, P = 0.97). Seven days intake of New Zealand blackcurrant extract does not change exercise-induced metabolic responses and 16.1 km cycling time trial performance for moderately endurance-trained men in normobaric hypoxia.

We examined effects of intake duration of New Zealand blackcurrant (NZBC) extract on cardiovascular responses during supine rest and moderate-intensity walking. Recreationally active men (n = 15, age: 24 ± 6 yr, BMI: 24.7 ± 4.3 kg·m⁻²) volunteered in a randomized, cross-over design. One metabolic equivalent (1-MET) was measured (3.97 ± 0.66 mL·kg⁻¹·min⁻¹) and an incremental walking test was performed to individualize speed at 4 (n = 3) or 5 (n = 12) METs for the 30-min walk (5.7 ± 0.7 km·hr⁻¹). NZBC extract (210 mg of anthocyanins) was taken with breakfast for 7 and 14 days, with a 14-days washout. The final dose was ingested 2-hr before recording of the cardiovascular responses (Portapres Model-2). At rest, %changes at 7- and 14-days intake were observed for stroke volume (+6.8% (trend), p = 0.065; +8.5%, p = 0.012), cardiac output (+10.1%, p = 0.007; +8.5%, p = 0.013), total peripheral resistance (−12.0%, p = 0.004; −13.1%, p = 0.011), diastolic (−5.7%, p = 0.045; −9.7%, p = 0.015) and mean arterial pressure (−4.4%, p = 0.040; −7.2%, p = 0.029), but without intake duration effect. During walking, %changes at 7- and 14-days intake were observed for stroke volume (+7.7% (trend), p = 0.063; +9.9%, p = 0.006), cardiac output (+8.7%, p = 0.037; +10.1%, p = 0.007), diastolic blood pressure (−6.2%, p = 0.042; −10.6%, p = 0.001), and total peripheral resistance (−9.6%, p = 0.042; −13.5%, p = 0.005) but without intake duration effect. During walking, %changes at 14-days were observed only for mean arterial pressure (−6.4%, p = 0.018) and arterio-venous oxygen difference (−7.9%, p = 0.019). NZBC extract affects cardiovascular responses at rest and during moderate-intensity exercise with 7- and 14-day intake. Only during moderate-intensity exercise, a longer intake of NZBC extract was required for an effect on some cardiovascular responses.

Background/Objectives: Chronic intake for 7 to 14 days of anthocyanin-rich blackcurrant extract or powder has been shown to alter cardiorespiratory and metabolic responses during rest and moderate-intensity exercise. Whether the observed effects were due to the final intake on the day of testing is not known. We examined whether there were effects of an acute intake of blackcurrant extract on the cardiorespiratory and metabolic responses during supine rest and moderate-intensity treadmill walking. Methods: Healthy men (n = 15, age: 24 ± 6 years, body mass index: 24.4 ± 4.5 kg·m⁻²) volunteered in a randomized, cross-over designed exploratory study. Acute intake effects of blackcurrant extract (210 mg of anthocyanins) were compared to a control condition. Hemodynamic recordings and indirect calorimetry techniques were used to record physiological and metabolic responses during 10 min of supine rest and 30 min of moderate-intensity treadmill walking. Results: At rest, there may have been an effect for an increase in cardiac output (p = 0.088). Based on the smallest worthwhile change (i.e., 0.2 × the standard deviation in the control condition), eight participants were classified as responders with an increase in cardiac output of 13.5 ± 8.4% (range: 4.0 to 24.7%). For total peripheral resistance, a decrease was observed (p = 0.048, d = −0.40, small effect size), with nine participants classified as responders with a decrease of 17.5 ± 6.1% (range: −9.7 to −28.0%). No changes were observed for other cardiorespiratory and metabolic parameters during supine rest. During moderate-intensity exercise, only heart rate was lower by 2 beats·min⁻¹ for the cohort (d = −0.11, trivial effect size) with four participants considered responders when presenting a heart rate lower than the smallest worthwhile change of 3 beats·min⁻¹. Conclusions: An acute intake of a blackcurrant extract with 210 mg of anthocyanins may have had an effect on vascular regulation mechanisms affecting total peripheral resistance and cardiac output during rest in at least ~50% of the male participants. No acute effects were observed for metabolic responses during rest and exercise. Our findings regarding the metabolic effects are not consistent with previous chronic dosing studies suggesting that repeated daily intake with a dose of 210 mg of anthocyanins is needed to alter substrate oxidation at rest and during moderate-intensity exercise.