Today, we will be looking primarily at this article:
To examine the potential significance of the supplement Tart Cherry and its anti-inflammatory effects!
When we perform high-intensity strength training exercises, damage occurs in the form of inflammation and microtears to the structure of the muscle, just to name a couple. For athletes especially, one of the most common ways to remedy this is through the use of Non-Steroidal Anti-Inflammatory Drugs (more commonly known as NSAIDs). These include commonly known over-the-counter medications such as ibuprofen and acetaminophen. However, there has been some controversy associated with its use in this regard, as it has been shown to inhibit the processes of muscle protein synthesis, which is the primary driver for muscle growth, strength, and repair after intense exercise.
It was because of this very controversy that researchers began delving into alternative ways to remedy this damage. One of these alternatives include fruits that contain high amounts of phytochemicals, which has shown in some of the scientific literature to provide a significant anti-inflammatory effect. More specifically, the study we will examine today looks at Montmorency cherries, which have been used in general health studies to analyze its effects on the aforementioned anti-inflammatory effects associated with particular diseases such as cardiovascular disease and osteoarthritis.
After the touted positive effects of cherry supplementation in these studies were published, two resistance exercise-based studies came to the forefront. One study examined 8 days of supplementation with tart cherry while performing 2 sets of 20 repetitions of maximal elbow flexion, in other words, the maximum amount of weight the subject could handle on the lowering portion of a bicep curl. Compared to placebo, muscle pain and strength losses were reduced in the tart cherry group.
In the other study, it was shown that isometric (muscle contraction with no movement, such as a plank) muscle strength recovery was improved with tart cherry supplementation when compared to no supplementation whatsoever. The current study aims to utilize these previously used tart cherry supplementation protocols to determine if they were to receive similar results in the attenuation of muscle soreness, strength loss, and markers of muscle damage.
The Primary Study We’re Looking At…
The study took 23 healthy,resistance-trained males in a randomized, double-blind, and placebo-controlled study design. The term “resistance-trained” when referring to subjects can be quite ambiguous. The researchers’ in this study used this term to refer to the fact that the individuals had the ability to barbell back squat 1.5x their body weight on a Smith Machine and have performed regular, consistent squat exercise training for at least 6 months prior to the study.
All subjects completed a had blood drawn after a 10 hour fast both at 5-time points during the study. These blood draws measured markers of muscle damage, oxidative stress, and inflammation. After the first fasting blood draw, subjects were matched on several characteristics such as squat strength and body weight and were then placed into either the placebo group (rice flour) or the tart cherry (powdered tart cherry supplement) group. The individuals were told to take the supplement for a total of 10 days.
As for the subjects’ diets, they were instructed to record their food and fluid intake for 4 out of the first 7 days of the study. The researchers’ goal in this was to reflect the person’s normal dietary intake. Body composition measures were analyzed via DEXA (Dual X-Ray Absorptiometry) which included the analysis of fat-free mass and fat mass. As for the exercise protocol itself, subjects performed 10 sets of 10 repetitions at 70% of their 1-repetition maximum (1RM).
The researchers found that the perception of soreness from the subjects in the tart cherry (TC) tended to be significantly lower than the placebo group (P). This was noted in the vastus lateralis and medialis, which are more commonly known as the “outer and inner quad” muscles, respectively. This was noted 48 hours after the exercise session. Another interesting find by the researchers was that serum levels of cortisol (more commonly known as the “stress hormone”) were significantly lower in the TC group compared to the P group; increasing by 13% in the placebo group but only 8% in the tart cherry group after the exercise bout.
What is this study really telling us?
This study was the first of its kind to investigate the effects of Montmorency tart cherry on acute resistance training performance and recovery. Although this was the first of its kind to do this, this study did have some notable flaws that inhibited its ability to fully demonstrate the effects of tart cherry on resistance training performance.
The study only utilized one strength training session throughout the entire 10 days of supplementation. Research studies are conducted for various reasons, but one of them is so that the results can be practically applied to real life scenarios. From recreational exercisers to the Olympic athlete, any of these populations rarely train only once in a 10-day cycle. Future research on this topic should utilize multiple sessions per week, with 3 sessions being the absolute minimum.
The limitation that really stands out here is of the dietary tracking. Food and fluid intake were tracked for 3 weekdays and 1 weekend day throughout the first week of the supplementation protocol. Usually, studies with a higher amount of subjects will implement this type of protocol due to a lack of resources for more in-depth dietary adherence tracking or simply for simplicity due to the high amount of individuals participating. But in a study such as this one, with its low subject number of 23, a more through dietary strategy could have been implemented, with, at the very least, dietary tracking being required for all 10 days of the supplementation protocol. This would have provided us with a better understanding of how (if even) the subjects’ nutrition affected the outcome(s) of this study.
However, despite the study’s weaknesses, it does utilize various strengths in its protocol that other similar studies did not. The vast amount of markers of muscle soreness, performance, damage, and inflammation captured during the blood draws was quite immense compared to other studies on this topic. The blood panel conducted on each subject was able to provide more in-depth results and answers (although many were not significant) to the question of “What effects does tart cherry supplementation have on acute performance and recovery during high-intensity resistance training?”
The Grand Scheme of Things
The benefits of tart cherry supplementation on perceived muscle soreness falls in line with previously published literature, with one study reporting consumption of tart cherry juice was able to significantly reduce pain in the flexors of the elbow using a subjective visual analog scale to assess pain. However, not all of the literature agrees, as another study reported no significant difference in pain reduction after a vigorous single leg knee extension protocol.
The trend of reduced markers of muscle damage is supported in other studies as well, with one, in particular, showing significant reductions in a common muscle damage biomarker known as creatine kinase (CK), when compared to placebo.
Along with muscle damage, an inflammatory marker known as Interleukin 6 (IL-6) was notably reduced after a marathon running event. This was illustrated by a quicker recovery of knee extensor (quads) maximal strength as compared to placebo. However, when this marker was examined in a protocol that utilized a resistance training regime, the results were not so positive. There was absolutely no significant difference in the levels of IL-6 before and after the initiation of the supplementation protocol with tart cherry.
The Final Verdict
So at this very moment, it is unclear what effects that tart cherry supplementation has on resistance training, despite the number of studies that are available on it. Fortunately, however, the current literature provides a solid basis for future research in terms of methodologies and standardizations to use.