Can you enhance exercise-induced fat oxidation with green tea drinking?

Green tea is associated with health benefits. Some studies showed enhanced exercise-induced fat oxidation with intake of capsulated green tea components, primarily with epigallocatechin-3-O-gallate, but that effect was never observed with drinking brewed green tea from unpowdered leaves. In 2013, Hodgson et al. published a review article on green tea intake and exercise-induced fat oxidation. This review will cover some of the green tea studies since 2013 with only one study on the effects of drinking green tea. A study in 2018 showed that drinking a few cups with normal amounts of powdered green tea leaves (i.e. Matcha) enhanced fat oxidation during brisk walking in females. Capsulated intake of green tea components but also regular drinking of normal amounts of Matcha have the potential to provide benefits for health and exercise

Anthocyanin-rich supplementation: emerging potential for sport and exercise nutrition

Intake of dietary supplements by athletes and recreationally active people is primarily aimed to enhance exercise performance, physical training adaptations and post-exercise recovery. The beneficial effects of the single ingredient supplements caffeine, nitrate, creatine, beta-alanine, and bicarbonate are recognized for specific exercise conditions. Evidence is emerging for the application in sport and exercise of the intake of multi-ingredient functional foods, e.g. cherries and berries. We present some observations from our studies on the effects of anthocyanin-rich New Zealand blackcurrant powder and extract that have implications for sport and exercise nutrition

New Zealand blackcurrant extract improves high-intensity intermittent running performance.

New Zealand blackcurrant (BC) intake showed reduced blood lactate during low and moderate intensity cycling and improved 16.1 km cycling time trial performance. We examined the effect of BC on high-intensity intermittent treadmill running and post-running lactate clearance. Thirteen active males (age: 25±4 yrs, stature: 1.82±0.07 m, body mass: 81±14 kg, V̇O2max: 56±4 mL∙kg-1∙min-1, velocity at V̇O2max: 17.6±0.8 km∙h-1, mean±SD) visited the laboratory three times. In the 1st visit, a ramp protocol (0.1 km∙h-1 every 5 sec) was completed to establish V̇O2max and velocity at V̇O2max, and subjects were familiarised with the protocols. In visits 2 and 3, subjects completed an high intensity intermittent running capability test which consisted of six 19 s high-intensity running bouts, each interspersed by 15 s of low-intensity running, followed by 1 minute of rest, this was repeated at increasing speeds, until exhaustion. Prior to visits 2 and 3, subjects consumed either New Zealand BC extract (300 mg∙day-1 CurraNZ™; containing 105 mg anthocyanin) or placebo (P) (300 mg∙day-1 microcrystalline cellulose M102) for 7 days in capsules (double blind, randomised, cross-over design, wash-out at least 14 days). Blood lactate was collected for 30 min post-exhaustion. Two-tailed paired t-tests were used and significance accepted at p< .05. BC increased total running distance by 10.6% (BC: 4282±833 m, P: 3871±622 m, p = .023, 10 out of 13 subjects improved), with the distance during the high-intensity running bouts by 10.8% (p= .024). Heart rate, rating of perceived exertion and oxygen uptake were not different between conditions for each stage. At exhaustion, lactate tended to be higher for BC (BC: 6.01±1.07 mmol∙L-1, P: 5.22±1.52 mmol∙L-1, p = .066, 9 out of 13 subjects). There was a trend towards improved lactate clearance following 15 min (BC: -2.89±0.51 mmol∙L-1, P: -2.46±0.39 mmol∙L-1, p = .07) and 30 minutes of passive recovery (BC: -4.12±0.73 mmol∙L-1, P: -3.66±1.01 mmol∙L-1, p = 0.11). It is concluded that New Zealand blackcurrant extract (CurraNZ™) may enhance performance in team sports characterised by high-intensity intermittent exercise as with BC intake greater distances were covered during high-intensity running, there was higher lactate tolerance, and increased lactate clearance after high-intensity exercise

Effects of Matcha green tea on heart rate variability and physiological and metabolic responses in young adult female

Introduction: Compared to other green teas, higher intake of multiple phytochemicals is achieved with Matcha green tea consumption. Green tea consumption is known to have metabolic effects but is also consumed for supposed calming effects. The aim of the present study was to examine the effects of encapsulated Matcha green tea on heart rate variability metrics during supine rest, as well as on physiological and metabolic responses during both supine rest and moderate-intensity exercise. Methods: Healthy females (n=8, age: 22±3 yrs, body mass: 68±11 kg, height: 162±5 cm) volunteered. The study employed a placebo-controlled, randomised cross-over design. Time-domain heart rate variability metrics during supine rest (n=5) and physiological and metabolic responses using indirect calorimetry techniques during supine rest and 60-min of moderate-intensity (~ 4-METs) treadmill walking (speed: 4.4±0.5 km·h-1) were measured following 3 weeks of 3 g·day-1 of Matcha green tea or placebo. Results: During supine rest with Matcha green tea, all participants had lower heart rates by 13±7% (P=0.01, d= -1.45), higher mean beat-to-beat RR intervals by 16±9% (P=0.03, d=1.25), higher SDNN by 44±32% (P=0.01, d=0.76) and higher pNN50 by 139±139% (P<0.01, d=1.28). Matcha green tea had no effects on the physiological and metabolic responses during supine rest and moderate-intensity treadmill walking (e.g. respiratory exchange ratio, placebo: 0.78±0.04; Matcha: 0.78±0.03, P=0.87). Fat oxidation during supine rest was correlated (r=0.75, P<0.01) with the moderate-intensity walking induced fat oxidation. Conclusions: In young adult healthy females, Matcha green tea beneficially effects heart rate variability metrics during supine rest indicating an alteration in parasympathetic nervous activity and therefore suggestive of a relaxing effect. Matcha green tea did not change the metabolic responses during supine rest and exercise possibly due to the low respiratory exchange ratio in the female cohort. Future work should address the effectiveness of Matcha green tea during conditions of psychological stress

Running-induced metabolic and physiological responses using New Zealand blackcurrant extract in a male ultra-endurance runner: A case study

Physical training for ultra-endurance running provides physiological adaptations for exercise-induced substrate oxidation. We examined effects of New Zealand blackcurrant (NZBC) extract on running-induced metabolic and physiological responses in a male amateur ultra-endurance runner (age: 40 yrs, body mass: 65.9 kg, BMI: 23.1 kg·m-2, body fat: 14.7%, V ̇O2max: 55.3 mL·kg-1·min-1, resting heart rate: 45 beats·min-1, running history: 6 years, marathons: 20, ultra-marathons: 28, weekly training distance: ~80 km, weekly running time: ~ 9 hours). Indirect calorimetry was used and heart rate recorded at 15-min intervals during 120-min of treadmill running (speed: 10.5 km·h-1, 58%V ̇O2max) in an environmental chamber (temperature: ~26°C, relative humidity: ~70%) at baseline and following 7-days intake of NZBC extract (210 mg of anthocyanins·day-1) with constant monitoring of core temperature. The male runner had unlimited access to water and consumed a 100-kcal energy gel at 40- and 80-min during the 120-min run. There were no differences (mean of 8, 15-min measurements) for minute ventilation, oxygen uptake, carbon dioxide production and core temperature. With NZBC extract, the respiratory exchange ratio was 0.02 units lower, carbohydrate oxidation was 11% lower and fat oxidation was 23% higher (control: 0.39±0.08, NZBC extract: 0.48±0.12 g·min-1, P<0.01). Intake of the energy gel did not abolish the enhanced fat oxidation by NZBC extract. Seven days intake of New Zealand blackcurrant extract altered exercise-induced substrate oxidation in a male amateur ultra-endurance runner covering a half-marathon distance in 2 hours. More studies are required to address whether intake of New Zealand blackcurrant extract provides a nutritional ergogenic effect for ultra-endurance athletes to enhance exercise performance

Effects of New Zealand Blackcurrant Extract on Sequential Performance Testing in Male Rugby Union Players

Previous studies on performance effects by New Zealand blackcurrant (NZBC) extract used mainly a single exercise task. We examined the effects of NZBC extract in a battery of rugby un-ion–specific tests including speed, agility and strength testing. University male rugby union players (n = 13, age: 21 ± 2 years, height: 182 ± 6 cm, body mass: 87 ± 13 kg) completed two full familiarisations and two experimental visits in an indoor facility. The study had a double blind, placebo-controlled, randomised, crossover design. For the experimental visits, participants con-sumed NZBC extract (210 mg/day of anthocyanins for 7 days) or placebo with a 7-day wash-out. Testing order was the running-based anaerobic sprint test, the Illinois agility test, seated medi-cine ball (3 kg) throw, and handgrip strength. With NZBC extract, there may have been an effect for average sprint time to be faster by 1.7% (placebo: 5.947 ± 0.538 s, NZBC extract: 5.846 ± 0.571 s, d = −0.18 (trivial), p = 0.06). However, with NZBC extract there may have been reduced slowing of sprint 2 (d = −0.59 (moderate), p = 0.06) and reduced slowing for sprint 6 (d = −0.56 (moderate), p = 0.03). In the Illinois agility test, there may have also been an effect for the mean time to be faster by 1.6% (placebo: 18.46 ± 1.44 s, NZBC extract: 18.15 ± 1.22 s, d = −0.24 (small), p = 0.07). The correlation between the %change in average sprint time and %change in mean agility time was not significant (Pearson R2 = 0.0698, p = 0.383). There were no differences for the seated medicine ball throw distance (p = 0.106) and handgrip strength (p = 0.709). Intake of NZBC extract in rugby union players seems to improve tasks that require maximal speed and agility but not muscle strength. NZBC blackcurrant extract may be able to enhance exercise performance in team sports that require repeated movements with high intensity and horizontal change of body position without affecting muscle strength