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Effect of New Zealand Blackcurrant on Recovery from Eccentric Muscle Damage in Triathletes

Authors:
RESEARCH PROJECT IN SPORT AND EXERCISE SCIENCE (66-6713-00S) 1
Effect of New Zealand Blackcurrant on Recovery from Eccentric Muscle Damage in Triathletes
Liam Oliver (b50007971)
Supervisor: Dr Mayur Ranchordas
Keywords: blackcurrant, antioxidant, supplementation, recovery, triathlon
Manuscript Word Count (excluding references, tables, figures): 3685
RESEARCH PROJECT IN SPORT AND EXERCISE SCIENCE (66-6713-00S) 2
Abstract
Background: Triathletes require optimal recovery to combat increasing competition demands.
Antioxidants supplementation, using extracts such as pomegranate and cherry, is a potentially
efficacious recovery strategy given the reported health benefits. Little research has monitored recovery
with New Zealand blackcurrant (NZBC). This study aims to investigate the effect of NZBC on recovery
from eccentric muscle damage in triathletes.
Methods: Seven male and female triathletes completed a double-blind, randomised, placebo-controlled
parallel-design experiment. Participants undertook eight days of 600 mg supplementation of CurraNZ
(210 mg anthocyanins) or cornflour placebo. An eccentric quadricep damage protocol took place on
day five. Creatine kinase, soreness, flexibility, countermovement jump, and maximal voluntary
isometric contraction were assessed over 72 hours.
Results: A two-way mixed ANOVA (2x6) found no significant difference between groups for any of
the measures. Soreness displayed a moderate effect of NZBC at 72h (d = 0.73, r = 0.34). There was no
significant effect of time or condition on peak torque and average peak torque, nor was there any time-
condition effect.
Conclusions: There was no significant effect of NZBC supplementation on recovery in triathletes. A
moderate effect on soreness was observed 72h post-exercise. Research should investigate CurraNZ
using crossover designs with exploration of biomarkers associated with muscle damage.
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Effect of New Zealand Blackcurrant on Recovery from Eccentric Muscle Damage in Triathletes
Introduction
Triathlon is an outdoor endurance sport involving swimming, cycling, and running. Optimal recovery
is crucial for triathletes to manage increasing performance demands (Olcina et al., 2017). Muscle
damage and performance impairments are consequences of competition (Cosa et al., 2014). Efficacious
supplements and foods, such as pomegranate, cherry and blackcurrant, are researched for potential
recovery promotion with the lure of anti-inflammatory and antioxidant effects (Willems et al, 2015).
This introduction explores muscle damage, polyphenol supplementation, and blackcurrant extract
specifically.
Muscle Damage
Exercise-induced muscle damage (EIMD), particularly from unaccustomed, eccentric muscle action, is
associated with temporary impairments in force production, edema, and the accumulation of
intramuscular proteins (Sousa, Teixeira and Soares, 2014). This is a result of mechanical (tension-
related) and metabolic stress (such as free radical production) (Baird et al., 2012). The appearance of
biochemical markers related to EIMD increases with endurance and resistance exercise. Creatine kinase
(CK) peaks after 48-to-72 hours (Totsuka et al., 2002) and is regarded as an indirect marker of damage
and potential antecedent to muscle soreness (Baird et al., 2012). Delayed onset of muscle soreness
(DOMS) presents itself 24-to-72 hours after exercise and is alleviated after five-to-seven days
(Ranchordas et al., 2012). Localised tenderness is a transient symptom, alongside pain and muscle
stiffness (Lewis, Ruby, & Bush-Joseph, 2010).
Polyphenol Supplementation
Plant-based polyphenol ingestion and supplementation, such as from tart cherry and blackcurrant, bears
potential health benefits (Willems et al., 2015; Gopalan et al., 2012). These fruits contain anthocyanins;
a subcategory of flavonoids. Further subdivisions include compounds with cytoprotective qualities such
as cyanidin and delphinidin (Nam et al., 2016). Oxidative stress from exercise may be counteracted
or hindered - by these antioxidant properties (Peternelj & Coombes, 2011). Research on potential
recovery improvements is therefore warranted.
Tart cherry supplementation reduced muscle damage from marathon running after five days (Howatson
et al, 2010). This may be explained by higher total antioxidant capacities; suggesting five-day
supplementation was effective. Ingestion of polyphenol-rich drinks, using cherries and blueberries, has
previously reduced soreness (Beals et al., 2016) and enhanced recovery (Bowtell et al., 2011; Mcleay
et al., 2012). Although practically feasible, food-based antioxidant intake is overlooked. Studies should
compare the effects of adequate dietary intake and further supplementation, with anthocyanin intakes
matched and reported, to advance research.
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The work of Trombold et al. (2010) showed 600 mg pomegranate improved strength recovery from
elbow flexion after three days in a randomised crossover-design experiment. Further research may
reinforce the effectiveness of 600 mg supplementation for recovery. Ammar et al. (2016) discovered
pomegranate improved DOMS and CK recovery in weightlifting. Although the non-randomised design
opens the potential for bias, the study was robust, with detailed methods and nutritional data in
performance contexts. Contradicting literature has emerged, however, with bilberry juice consumption
having a possibly harmful effect on DOMS from pre- to post-race in a half-marathon (Lynn et al., 2018).
This highlights the possibility of blunted adaptations (Panza et al., 2015). Polyphenol-rich foods such
as cherry (Damar & Eksi, 2012) and blackcurrant (Kähkönen et al., 2003) vary in their antioxidant
contents. Each food therefore has potentially unique effects on exercise and health outcomes. Current
knowledge indicates potential recovery benefits from supplementation in sport. Investigation of
biological mechanisms, including total antioxidant capacities and endothelial nitric oxide (NO)
generation, is encouraged considering the documented increases of these markers with supplementation
(Leelayuwat, 2017; Martin et al., 2002), and force reductions associated with NO (Radák et al., 1999).
Blackcurrant Extract
Blackcurrant (Rubes nigrum L.) boasts high quantities of the cytoprotective compounds, cyanidin and
delphinidin (Gopalan et al., 2012). CurraNZ a popular supplement (see Table 1). One capsule contains
105 mg of anthocyanins (35-50% delphinidin-3-rutinoside, 20% delphinidin-3-glucoside 520%, 30-
45% cyanidin-3-rutinoside, 3-10% cyanidin-3-glucoside) (CurraNZ, Surrey, Health Currancy, CurraNZ
Ltd). Czank et al. (2013) suggested the half-life of anthocyanins is under 48 hours. The need for daily
supplementation with a minimum of 48-hour follow-up measures is therefore clear.
Preliminary data suggested blackcurrant extract may reduce muscle soreness following eccentric
exercise-induced muscle damage for 48 hours post-exercise, with a similar trend for CK at 72 and 96
hours (Coelho et al., 2017). Supplementation between 300 and 900 mg CurraNZ increased resting stroke
volume and cardiac output, and reductions in total peripheral resistance with dose-response effects
(Willems et al., 2016; Cook et al., 2016). Greater flow-mediated dilation (FMD) and peripheral blood
flow are potential mechanisms. Cook et al. (2015) observed significant increases in fat oxidation,
potentially via increased gene upregulation, as well as improved performance in trained cyclists.
Performance benefits have been observed in repeated cycling time trials (Murphy, Cook, & Willems,
2017) and running (Perkins et al., 2015; Godwin, Cook, & Willems, 2017). Peripheral fatigue may have
been reduced with NZBC through intracellular acidosis, counteracting ion imbalances during muscular
action. Measuring acute pain subjectively using visual analogue scales would offer a validity and
reliable method of strengthening the literature (Gallagher et al., 2002).
RESEARCH PROJECT IN SPORT AND EXERCISE SCIENCE (66-6713-00S) 5
Triathlon training and performance changes markers of oxidative stress significantly (Medina et al.,
2012). Markers of muscle damage become exacerbated leaving athletes susceptible to soreness,
inflammation, and reduced strength in response to EIMD (Wu et al., 2002). Many therefore compete in
the absence of full recovery (Olcina et al., 2017). Antioxidant supplementation shows promise in
rescuing recovery, yet this is overlooked in the CurraNZ literature. Considering the recovery promotion
seen elsewhere, blackcurrant may show similar findings.
This study examined the effects of eight-day New Zealand blackcurrant (NZBC) supplementation on
recovery from EIMD in triathletes. It was hypothesized NZBC would improve CK recovery and
soreness, and produce smaller reductions in isometric strength, flexibility, and jump performance as
opposed to placebo (PLA).
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Table 1. A summary of research using CurraNZ as a nutritional intervention.
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RESEARCH PROJECT IN SPORT AND EXERCISE SCIENCE (66-6713-00S) 8
Methods
Participants
Seven male and female (six males, one female) recreational triathletes (age: 24.3 ± 4.4 years; body
mass: 74.6 ± 9.8 kg; stature: 174.2 ± 8.3 cm) volunteered. Participant characteristics are seen in Table
2, with inclusion and exclusion criterion in Table 5. Participants were asked to avoid additional
nutritional supplementation throughout. Recruitment entailed emailing students and local triathlon
clubs. Social media websites, such as Twitter and Facebook, and word of mouth increased outreach.
Participants were asked to refrain from caffeine, exercise and alcohol 24 hours before the EIMD
protocol and for 72 hours after. Prior to participation, informed consent was obtained. The Sheffield
Hallam University Medical Questionnaire and Physical Activity Readiness Questionnaire were
completed by participants preceding involvement. The Sheffield Hallam University Ethics Committee
provided ethical approval.
Design and Procedures
This study employed a double-blind, randomised, placebo-controlled parallel design. Two groups were
assigned by simple randomisation using Microsoft Excel 2013. Creatine kinase, perceived soreness,
flexibility, and maximal voluntary isometric contraction were measured.
Supplementation
The treatment group (n = 3) received eight-day 600 milligram (mg) supplementation of CurraNZ
(Surrey, Health Currancy, CurraNZ Ltd). This involved ingestion of two 300 mg capsules (210 mg
anthocyanins) per day for five consecutive days prior to the protocol and for three days after. The
placebo group (n = 4) ingested two capsules of 300 mg cornflour in the same manner. Blinding success
was assessed by asking participants which condition they believed they were assigned.
Characteristic
NZBC
PLA
Demographics
Age (years)
25 ± 5
23.8 ± 3.8
Stature (cm)
171.8 ± 10.8
176 ± 5
Body mass (kg)
68.3 ± 11.5
79.3 ± 4.2
Dietary Intake
Calories (kcal)
1425 ±489
1169 ± 172
Carbohydrate (g)
165.7 ± 49.7
(2.4 ± 0.5)
133.5 ± 15.5
(1.7 ± 0.2)
Protein (g)
62.3 ± 26.5
(0.9 ± 0.3)
44.8 ± 5.9
(0.6 ± 0.1)
Fat (g)
57 ± 29.7
(0.8 ± 0.3)
48.5 ± 14.6
(0.6 ± 0.2)
Anthocyanins (mg)
33.9 ± 27.9
10 ± 16.6
Table 2. Participant characteristics and anthocyanin intake for each
group (mean ± SD).
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Procedures
Body mass (kg) and stature (cm) were measured using a Seca 285 measuring station (Seca GMBH,
Germany). The muscle damage (EIMD) protocol comprised ten sets of ten eccentric quadricep
contractions using isokinetic dynamometry (System 3 Pro, Biodex Medical Systems Inc., USA). The
non-dominant limb was involved. This was determined by asking participants which was their
‘dominant’ leg used for kicking. The leg was moved passively through a 70° range of motion for
contractions. One-minute of passive rest was provided between sets. A 90° angle was defined using the
natural hang of the leg. As conducted by Mcleay et al. (2012), seat adjustments aligned the femoral
epicondyle with the axis of rotation. The ankle was strapped five centimetres proximal to the medial
malleolus. The chest, hips, and legs were strapped to isolate the quadricep. Participants were asked to
provide voluntary maximum effort. A familiarisation session was conducted two-to-seven days prior to
the damage protocol, before eight-day supplementation was provided. Methods of daily reminders were
agreed upon and sent during the supplementation period, outlining the instructions. Figure 1 illustrates
the procedures. Measures were taken in the same order immediately before (0h-pre), after (0h-post),
and 24, 48, and 72 hours post-exercise. A pilot study determined the protocol produced marked
increases in CK and DOMS, with decreases in maximal voluntary isometric contraction (MVIC).
Participants undertook measures in the following order: creatine kinase (CK), perceived soreness
(DOMS), flexibility, countermovement jump, and MVIC. A Reflotron Photometer (Boehringer
Mannheim, Germany) measured CK (U/L) at 25° Celsius from fingertip capillary blood samples.
DOMS was measured as general soreness using a pen-and-paper visual analogue scale (VAS) from 0-
100 millimetres, defining 0 as “no pain” and 100 as “unbearable pain”. In each session, a standardised
dynamic warm-up (Opplert & Babault, 2017) was performed after CK and DOMS to avoid influences
in results and allow sufficient preparation for all other measures. This consisted of a three-minute cycle
at 50% perceived effort on a cycle ergometer (824E, Monark Exercise AB, Sweden) followed by ten
bodyweight squats, alternating lunges and alternating hamstring sweeps each. The sit-and-reach test
(Cranlea) assessed hamstring ROM with three attempts, interspersed by one-minute of rest. Three
countermovement jump attempts allowed the calculation of peak force (N), given the reductions in jump
performance following triathlon competition (Olcina et al., 2018), using a portable force plate (9286BA,
Kistler, Switzerland). Sampling frequency was set at 1000 Hz over six seconds. One-minute rest
intervals were given. Isokinetic dynamometry quantified MVIC at the non-dominant quadricep,
positioned at a 75° extension. Knee extensor strength is another variable impaired by triathlon
participation (Olcina et al., 2018). Equipment alignments simulated those in the EIMD protocol.
Participants warmed up with one set of five isometric leg extension repetitions, beginning with 50%
effort and increasing to a final maximum effort, before one-minute of rest was allowed. The protocol
then began with maximal isometric contractions for three sets of five repetitions, separated by three
minutes of rest. Peak torque and average peak torque (Nm) were recorded.
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Dietary Standardisation
Participants continued and reported their habitual diet for the 48 hours before EIMD. Nutritics software
estimated dietary intake (Nutritics LTD., Dublin, Ireland). Participants were allowed water ad libitum
in each session. Individual and mean dietary anthocyanin contents were calculated with Phenol Explorer
(Neveu et al., 2010). This was defined as the consumption frequency of anthocyanin-containing foods
multiplied by the anthocyanin content for approximate portion sizes (Cook et al., 2017). Participants’
dietary intake is recorded in Table 2.
Figure 1. A visual summary of procedures.
Data Analysis
A priori power analysis considered a sample size of seven per group as necessary for high statistical
power (𝛽 = 0.80; 𝛼 = 0.05) based on research conducted by Trombold et al. (2010). A two-way
mixed ANOVA (2 x 6) assessed the effect of condition and time, respectively, and the time-condition
interaction for all measures (condition: NZBC or PLA; and time: 0h-pre, 0h-post, 24h, 48h, 72h) using
SPSS (Version 24, SPSS Inc., USA). A Shapiro-Wilk test confirmed normality. Statistical significance
was accepted as p < 0.05, with confidence intervals of 95%. Levene’s test analysed equality of variance.
Homogeneity of data was determined by Mauchley’s test of sphericity. Where sphericity was violated
(p < 0.05), the adjusted Greenhouse-Geisser value was reported. F values and degrees of freedom were
calculated, with effect sizes (r) and Cohen’s d reported. Effect sizes were established as: 0.2, 0.6, 1.2,
2.0 and 4.0 (small, moderate, large, very large, and extremely large, respectively) for standardised
differences in the means (Hopkins et al., 2009; Lakens, 2013). Means and standard deviations (SD)
were calculated in Microsoft Excel 2013.
MEASURES:
CREATINE KINASE
DOMS
FLEXIBILITY
COUNTERMOVEMENT JUMP
MVIC
RESEARCH PROJECT IN SPORT AND EXERCISE SCIENCE (66-6713-00S) 11
Results
Blinding was successful in two participants in the control group. Levene’s test showed no significant
variance in measures except for creatine kinase (CK) and average peak torque 48 hours post-exercise.
All measures met the assumptions of sphericity, except for these two measures.
Creatine Kinase
There was no significant effect of condition on CK between groups, F (1, 5) = .866, p = .395. There
was no time-condition effect for creatine kinase, F (4, 20) = .093, p = .984. Within-participant
differences showed CK did not increase significantly F (1.10, 5.47) = 4.25, p = .088, with the
Greenhouse-Geisser output used due to a violation of sphericity (p = .000).
Muscle Soreness
Condition had no significant effect on perceived muscle soreness (DOMS), F (1, 5) = 176, p = .692.
There was no time-condition effect, F (4, 20) = .093, p = .984. DOMS increased significantly within
participants over time F (4, 20) = 5.66, p = .003. There was no time-condition effect, F (4, 20) = .706,
p = .597. There may have been an effect in favour of NZBC (Figure 3) between groups at 72h (r = 0.34,
d = 0.73) yet interpretation is limited due to the small sample size and large variability (Table 9).
Flexibility
There was no significant effect of time, F (4, 20) = 2.00, p = .133, or time-condition, F (4, 20) = .884,
p = .491 on flexibility. Between participants, there was no significant difference, F (1, 5) = 1.15, p =
.333.
Peak Force
No significant effect was found of peak force within participants over time, F (4, 20) = 2.00, p = .133,
nor was there a time-condition effect F (4, 20) = .884, p = .491. Condition showed no significant effect
between groups F (1, 5) = 1.15, p = .333.
Figure 3. Mean (±SD) changes in perceived muscle soreness
(DOMS) 0h-pre, 0h-post, 24h, 48h, and 72h after an EIMD protocol.
0
10
20
30
40
50
60
70
Pre Post 24h 48h 72h
DOMS (0-100 mm)
Time Point
NZBC
PLA
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Maximal Voluntary Isometric Contraction
Time had no significant effect on peak torque within participants, F (4, 20) = 1.94, p = .984. There was
no time-condition interaction, F (4, 20) = 2.04, p = .128. Statistical analyses showed no significant
difference between conditions F (1, 5) = .911, p = .384 (Figure 4). There was no significant effect of
time on average peak torque, F (1.35, 6.77) = 1.12, p = .351. No time-conditions effects were observed
F (1.35, 6.77) = 2.56, p = .153. There was no significant difference between groups, F (1, 5) = .886, p
= .390 (Figure 5).
Figure 5. Mean (±SD) changes in average peak torque (N·m) 0h-pre,
0h-post, 24h, 48h, and 72h after an EIMD protocol.
100
120
140
160
180
200
220
240
Pre Post 24h 48h 72h
Average Peak Torque (N·m)
Time Point (h)
NZBC
PLA
100
120
140
160
180
200
220
240
Pre Post 24h 48h 72h
Peak Torque (N·m)
Time Point
NZBC
PLA
Figure 4. Mean (±SD) changes in peak torque (N·m) 0h-pre, 0h-post,
24h, 48h, and 72h after an EIMD protocol.
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Discussion
The purpose of this study was to examine the effect of New Zealand blackcurrant (NZBC)
supplementation on recovery from eccentric exercise-induced muscle damage in triathletes. There was
no significant effect of NZBC on any recovery indices. The hypothesis was not supported, therefore, in
that soreness was not significantly less reduced, CK recovery was not better accelerated, nor were
reductions in isometric strength, flexibility, and jump performance significantly improved with
blackcurrant supplementation. Given the small sample size, interpretations must be careful. There may
have been an effect of NZBC on perceived muscle soreness (DOMS) between groups at 72 hours post-
exercise, however. DOMS appeared to be increased within participants over time, suggesting the EIMD
protocol may have been associated with increased soreness. Anthocyanins from blackcurrant ingestion
yield poor bioavailability, with urinary excretions of 0.021 ± 0.003% for delphinidin and 0.009 ±
0.002% cyanidin (Jin et al., 2011). Blackcurrant has been shown to increase nitric oxide production,
which is associated with force production decrements and soreness (Radák et al., 1999), This is through
the activation of endothelial nitric oxide synthase (Edirisinghe et al., 2011), facilitating vasorelaxation.
Research should further explore peripheral fatigue and the roles of intracellular acidosis, vasorelaxation
and gene upregulation (Cook et al., 2015; Godwin et al., 2017). The results of the unaccustomed
eccentric damage protocol may have been influenced by the repeated bout effect’, a phenomenon
possibly linked to neural, mechanical and cellular adaptation (Lima & Denadai, 2015). The placebo
effect (Rawdon et al., 2012) offers plausible reasoning influences in results, attributed to the blinding
success in two participants in the control group.
The present study does not hold the power to consolidate recovery improvements found with NZBC
supplementation (Coelho et al., 2017). Although preliminary, the authors saw significantly reduced
muscle soreness with treatment for 48 hours post-exercise compared to placebo. This study extended to
96 hours of recovery with a similar eccentric protocol (elbow flexion). However, research must replicate
sport-specific contexts. With only preliminary data to critique, further detail is required for in-depth
analysis. Despite not withholding statistical significance, the present study alludes to soreness
alleviations in the first 48 hours of recovery with NZBC. There exists the possibility of responders and
non-responders, with individual data indicating recovery promotion in some but not others (Tables 6-
9). The ability to tolerate high training volumes predicts relative success in triathlon (Knechtle et al.,
2015). The potential benefits of blackcurrant supplementation on soreness over 48 hours should be
recognised, as this study shows glimpses of practical significance for recreational triathletes.
Attention should be paid to alternative supplements, also. Pomegranate improved 72-hour-recovery
from elbow flexion EIMD in a randomised crossover-design experiment (Trombold et al., 2010). Given
the accumulation of 600 mg dosages in the literature, this appears an effective dose. Strengthening this,
pomegranate improved DOMS and CK recovery from a weightlifting session (Ammar et al., 2016). As
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in this study, dietary standardisation in research must be more rigorous given the limitations of self-
reported diaries (Gemming et al., 2013). Despite being a placebo-controlled study, contradictory
research has surfaced, with bilberry juice showing possibly harmful effects on DOMS pre-to-post-
exercise, and likely harmful on C-reactive protein levels 48 hours after a half-marathon (Lynn et al.,
2018). Research ought to consider the use of magnitude-based inferences to make direct comparisons
with free spreadsheets available (Hopkins, 2006). Elsewhere, tart cherry and blueberry consumption
have been shown to rescue recovery (Howatson et al., 2010; Bowtell et al., 2011). These studies
measured CK and MVIC as muscle damage markers, also. Research should consider including rate of
force development as a measure of muscle damage, given it is more sensitive to EIMD (Peñailillo et
al., 2015). With widespread research on different antioxidants, and each having distinct benefits (Damar
& Eksi, 2012; Kähkönen et al., 2003), researchers must appreciate the value of exploring the benefits
of antioxidant intake through polyphenol-rich foods in addition to supplementation.
Strengths and Limitations
This study adds to the paucity of literature investigating the effects of CurraNZ on muscle damage
recovery. The methods were thorough, seemingly producing expected strength reductions and soreness.
Recovery measures were robust, spanning 72 hours. This is rarely seen in the blackcurrant literature
(Coelho et al., 2017), strengthening the meaningfulness of the data were high statistical power achieved.
Despite the limited practical relevance of the damage-inducing method, the measures taken were
relevant to triathlon given the associations of strength and power with endurance performance (Olcina
et al., 2018). Dietary standardisation considered the potential dietary influences on results.
The present study was an independent-measures, parallel design. Most CurraNZ studies use crossover
methods. Variation in the results of this study therefore reflect interindividual differences rather than
responses within individuals. Post-exercise dietary intake may have influenced results, particularly with
possible recovery improvements from carbohydrate, fluid, and protein intake (McCartney, Desbrow, &
Irwin, 2017). The issue of under-reporting with self-reported intake (Gemming et al., 2013) should be
acknowledged. Due to cost and convenience, the absence of additional inflammatory markers and other
measures such as RFD (Peñailillo et al., 2015) limits the strength of this experiment. The population
range left measures open to wide variability, such as inconsistencies in CK (Brancaccio, Maffulli, &
Limongelli, 2007). However, the population recruited considered the demographics of triathletes since
performance peaks at unpredictable stages of an athlete’s career (Knechtle et al., 2015). The chosen
analyses aimed to control the probability of type I error yet would have been more effective had the
study possessed high power (Christley, 2010) and utilised magnitude-based inferences (Hopkins, 2006).
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Practical Implications and Future Research
This will contribute to informing recovery practice in triathlon and endurance sport. In-house
experimentation with NZBC is encouraged. Athletes should be aware of potential impairments of
muscle damage on prolonged recovery (72 hours or more), with blackcurrant extract carrying the
potential to mitigate recovery impairments. Research should be strengthened through investigation of
antioxidant supplementation in competition and training. In blackcurrant-based studies, additional
biochemical markers, such as interleukin-6, antioxidant status and nitric oxide, are required to better
understand the mechanisms. The bioavailability and half-life of antioxidants should be considered to
identify potential time limits of supplementation. The effects of estimated dietary antioxidant intake
alongside or as opposed to supplementation should be explored, with attention paid to the matching
of intakes. Studying the effects of acute supplementation (1-3 days) on recovery could boast practically
meaningful results given the short turnover of competition and simultaneous increased recovery
demands of sport.
Conclusion
In conclusion, the present study does not carry sufficient power to provide statistically meaningful
results. However, the potentially positive impact of blackcurrant supplementation on recovery should
not be overlooked. The practical importance of enhanced recovery in triathletes should be recognised
given the association of training variables with performance, and the challenge of simultaneous
increases in performance demands (Knechtle et al., 2015; Olcina et al., 2017). Research should examine
recovery extending to 72 hours, with rigorous methods relevant to triathlon contexts.
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RESEARCH PROJECT IN SPORT AND EXERCISE SCIENCE (66-6713-00S) 22
Table 5. Inclusion and exclusion criteria for eligibility.
Inclusion Criteria
Exclusion Criteria
Aged 18-45
Refusal to complete PAR-Q
Free of cardiovascular and
respiratory disease
Withdrawal
Recreationally active in
running, cycling, and/or
swimming (at least two out
of three)
Failure to meet all inclusion
criteria
One triathlon event minimum
in previous 12 months
Displays health problems
following medical
questionnaires i.e. ‘yes’ to two
or more on PAR-Q
Six months free of injury that
has kept the individual out of
training for two weeks or
more
RESEARCH PROJECT IN SPORT AND EXERCISE SCIENCE (66-6713-00S) 23
Table 6. Mean values (± SD) for all measures and time points in each group.
Variable
NZBC
PLA
0h Pre
0h Post
24h 48h
72h
0h
Pre
0h Post
24h 48h
72h
Creatine
Kinase (U/L)
52.4 ± 23.2
56.3
±19.6
109.8
±62.2
68.6 ±30.3
40.3
±11.7
67.7 ± 8.0
67.5
±11.2
129.4
±76.0
76.0
±37.0
68.0 ±26.5
Soreness (0-
100)
4.3 ±4.5
38.7
±20.8
28.0
±34.1
21.0 ±21.5
21.0
±22.7
5.3 ±4.6
26.3
±17.2
24.0
±16.5
25.3
±19.0
8.8 ±6.6
Flexibility
(cm)
17.7 ±11.0
15.5
±11.0
14.6
±10.0
14.7 ±11.2
17.0
±14.0
23.8 ±6.7
23.7
±7.7
23.3
±7.3
22.4
±7.0
23.3 ±6.9
Peak Force
(N)
1678.5 ±570.8
1440
±352.8
1793.6
±513.0
1829.9
±529.3
1814.7
±582.7
1770.6
±343.5
1772.6
±375.9
1805.6
±268.
2
1854.6
±413.7
2049.7
±456.5
Peak Torque
(Nm)
181.8 ± 32.2
179.6 ±
47.7
175.2
± 46.0
180.2 ±
59.2
183.0
± 63.5
230.4 ± 19.2
202.1 ±
17.7
208.7
± 33.4
196.3 ±
19.5
191.3 ± 31.6
Average Peak
Torque (N∙m)
157.5 ± 28.5
158.1 ±
45.3
156.2
± 48.2
161.8
±56.9
165.8
± 56.8
204.9 ± 25.4
182.7 ±
18.7
184.9
± 18.9
176.6 ±
17.0
165.6 ± 22.8
RESEARCH PROJECT IN SPORT AND EXERCISE SCIENCE (66-6713-00S) 24
Table 7. Individual changes in average peak torque (N·m) as absolute values over time for each participant.
*NZBC, New Zealand blackcurrant (treatment group)
Table 8. Within-participant changes in peak torque (N·m) as absolute values over time.
*NZBC, New Zealand blackcurrant (treatment group)
Condition /
Participant
0h PRE
0h POST
24h
48h
72h
Placebo
Participant 1
221.4
199.9
214.2
162.4
135.1
Participant 2
223.7
193.0
199.6
200.6
188.3
Participant 3
205.5
180.5
183.8
176.3
176.3
Participant 4
168.8
157.4
158.5
167.1
162.8
NZBC*
Participant 1
125.5
105.9
100.5
96.3
100.3
Participant 2
166.9
186.4
185.7
198.9
196.0
Participant 3
180.2
182.0
182.3
190.3
201.1
Condition /
Participant
0h PRE
0h POST
24h
48h
72h
Placebo
Participant 1
247.4
213.7
197.7
182.1
161.4
Participant 2
244.1
215.7
251.2
221.6
229.7
Participant 3
223.7
201.7
197.8
201.5
204.1
Participant 4
206.3
177.3
171.5
179.9
169.8
NZBC*
Participant 1
144.8
124.9
122.6
111.8
109.8
Participant 2
202.9
209.6
207.8
215.0
216.6
Participant 3
197.8
204.5
195.3
213.7
222.6
RESEARCH PROJECT IN SPORT AND EXERCISE SCIENCE (66-6713-00S) 25
Table 9. Individual changes in perceived muscle soreness (DOMS, 0-100 mm) over time in each group.
*NZBC, New Zealand blackcurrant (treatment group)
Condition /
Participant
0h PRE
0h POST
24h
48h
72h
Placebo
Participant 1
0
43
32
46
10
Participant 2
6
37
37
27
16
Participant 3
11
5
0
0
0
Participant 4
4
20
27
28
9
NZBC*
Participant 1
4
62
66
43
45
Participant 2
0
32
0
0
0
Participant 3
9
22
18
20
18
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New Zealand blackcurrant (NZBC) extract increased 16.1 km cycling time trial performance. The aim of the present study was to examine the effect of NZBC extract on 2 × 4 km time trial performance. Ten male cyclists (age: 30 ± 12 years, body mass: 74 ± 9 kg, height: 179 ± 7 cm, body fat: 11 ± 3%, (V̇) O2max: 55 ± 7 mL•kg−1•min−1, mean ± SD) volunteered. Participants were familiarized with the time trials. Participants consumed capsulated NZBC extract (300 mg∙day−1 CurraNZ™; containing 105 mg anthocyanin) or placebo for seven days (double blind, randomised, cross-over design, wash-out at least seven days) before 2 × 4 km time trials (10 min active self-paced recovery between trials) (SRM ergometer, SRM International, Germany). Heart rate was recorded and blood lactate sampled immediately after each trial and 8 min into recovery between the trials. Times over comparable one km distances in each 4 km time trial were similar. No effect was observed for the time to complete the first (placebo: 380 ± 28 s, NZBC: 377 ± 27 s) and second 4 km of cycling (placebo: 391 ± 32 s, NZBC: 387 ± 30 s), within both groups the second 4 km times slower by 11 ± 8 s and 11 ± 9 s for placebo and NZBC, respectively. However, the total time of the two 4 km cycling trials was 0.82% faster with NZBC extract (placebo: 771 ± 60 s, NZBC 764 ± 56 s, p = 0.034) with seven participants having faster total times. There was no effect of NZBC on heart rate and lactate values at identical time points. New Zealand blackcurrant extract seems to be beneficial in repeated short-distance cycling time trials for overall performance
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Background The effects of a multi-ingredient performance supplement (MIPS) on markers of inflammation and muscle damage, perceived soreness and lower limb performance are unknown in endurance-trained female athletes. The purpose of this study was to determine the impact of MIPS (NO-Shotgun®) pre-loaded 4 weeks prior to a single-bout of downhill running (DHR) on hsC-Reactive Protein (hsCRP), interleukin (IL)-6, creatine kinase (CK), muscle soreness, lower limb circumferences and performance. Method Trained female runners (n = 8; 29 ± 5.9 years) (VO2max: ≥ 50 ml-1.kg-1.min-1, midfollicular phase (7-11 days post-menses) were randomly assigned in a double-blind manner into two groups: MIPS (n = 4) ingested one serving of NO Shotgun daily for 28 days prior to DHR and 30 min prior to all post-testing visits; Control (CON) (n = 4) consumed an isocaloric maltodextrin placebo in an identical manner to MIPS. hsCRP, IL-6, CK, perceived soreness, limb circumferences, and performance measures (flexibility, squat jump peak power) were tested on 5 occasions; immediately before (PRE), immediately post-DHR, 24, 48 and 72 h post-DHR. ResultsThere were main effects of time for CK (p = 0.05), pain pressure threshold (right tibialis anterior (p = 0.010), right biceps femoris (p = 0.01), and left iliotibial band (ITB) (p = 0.05) across all time points), and maximum squat jump power (p = 0.04). Compared with 24 h post-DHR, maximum squat jump power was significantly lower at 48 h post-DHR (p = 0.05). Lower body perceived soreness was significantly increased at 24 h (p = 0.02) and baseline to 48 h (p = 0.02) post DHR. IL-6 peaked immediately post-DHR (p = 0.03) and hsCRP peaked at 24 h post-DHR (p = 0.06). Calculation of effect sizes indicated a moderate attenuation of hsCRP in MIPS at 72 h post-DHR. Conclusions Consumption of MIPS for 4 weeks prior to a single bout of DHR attenuated inflammation three days post, but did not affect perceived soreness and muscle damage markers in endurance trained female runners following a single bout of DHR.
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Eccentric exercise and unaccustomed overload exercise were shown to cause muscle damage and soreness (DOMS). The phenomenon is still not completely understood. Many mechanisms are responsible for the soreness, including oxidative stress, inflammation, and mechanical stress disruption. DOMS reduces force production leading to reduced physical performances, e.g., endurance and strengthening performances. Among many modalities preventing and treating the DOMS, antioxidant and antinociceptic supplements are increasingly used for health promotion and sport competition. This chapter provided update of the information of these supplements for those purposes.
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tion was to assess the effect of a tart cherry beverage (TCB) on delayed onset muscle soreness (DOMS). METHODS: Participants underwent assessment of the quadriceps for pain, muscle tenderness, thigh girth, flexibility, strength, and markers of muscle inflammation and damage at baseline, immediately following, and 24 h, 48 h, 96 h, and one week post-eccentric fatigue protocol while consuming TCB (N = 15) or placebo (N = 14). Two-way mixed ANOVA assessed the effects of time, group, and interaction for all variables except pain, which was assessed using Wilcoxon rank sum tests (p < 0.05). RESULTS: No significant main effect of group and no significant interaction was demonstrated between group and time, but a significant main effect of time was revealed for thigh girth, tenderness, flexibility, and strength (p < 0.001-0.003). For pain, change over time from baseline to post-fatigue was higher in the TCB group (p= 0.008). No statistically significant main effect of time, group, or interaction effect between time and group was demonstrated for cytokine data. CONCLUSION: Results from this study provide important insights to methodological issues that will guide future studies using TCB including, dose of anthocyanins, muscle groups to study, fatigue protocols to use and length of supplementation.