The supplement industry is abound with products aimed at increasing your body’s “fat burning” with the idea of improving fat loss. Often these fat burners are marketed as magic fat loss pills. Their “proprietary ingredient” list is chalk full of fancy sounding things from exotic plants that speed fat loss. Recently, some scientists investigated one of the “fat-loss” products to see if it improved fat oxidation, mood state, and some other interesting measures in an exercise trial.
Did the magic pill produce magic results?
Acute effectiveness of a “fat-loss” product on substrate utilization, perception of hunger, mood state and rate of perceived exertion at rest and during exercise
12 healthy, recreationally active adults (5 F, 7 M) with a mean BF of 21.3%. They were extensively screened for confounding factors (cardiovascular issues, supplements, etc.). They completed a 3-day 24 hour food diary (didn’t say what method was used).
The experiement consisted of 3 sessions.
- First session: Participants conducted a ramp protocol on a cycle ergometer to measure VO2 peak and assessed training level of max fat oxidation (FATMAX).
- Second and Third/Final Session: participants came in and conducted 30 minutes of cycling at their FATMAX level after either consuming a placebo or SHRED*.
During the protocol gas analysis was conducted and indirect calorimetry was used to assess fat and CHO oxidation levels between the two treatments at three time points: 1) Pre 1: 150 minutes before exercise, Pre 2: Immediately before exercise, Pre 3: Post exercise.
Also during the exercise protocol both heart rate (polar heart rate monitor) and perceived exertion (RPE, Borg RPE scale) were measured every 3 minutes during the tests.
After each of the two session (placebo or SHRED) they rested for 150 minutes. Resting HR, BP were taken, perception of hunger was taken every 30 minutes.
Additionally, mood state was assessed just after the ingestion (150 min before exercise), immediately pre and post exercise.
In this experiment the participants were given either SHRED or a placebo.
Here is how SHRED and placebo are described by the authors,
“During the second and third visits, after assessment of body composition, participants were randomized to ingest 1.5 g (3 × capsules) of either a multiingredient supplement (SHRED), (Shred-Matrix®, MusclePharm Corporation, USA), or a placebo (PL) containing maltodextrin and hemp protein powder, presented in similar-appearance capsules to SHRED. Three capsules with similar coatings of either SHRED or PL were placed within an empty water cup and taken in the same way with a 240 ml of water. The SHRED capsules contained Green Tea Extract, Yerba Maté, Guarana Seed Extract, Anhydrous caffeine, Saw palmetto, Fo-Ti, Eleuthero root, Cayenne Pepper, and Yohimbine HCI. The thermogenic ingredients per capsule included approximately 70 mg of green tea leaf, 50 mg caffeine anhydrase, and 100 mg of Guarana seed extract. The exact content and other ingredients are in a proprietary blend.”
Now there are some conjectures I would like to make here. The first is that the placebo contained ~1.5 grams of maltodextrin and hemp protein powder, which is essentially akin to taking nothing. 1.5 grams of a carb/protein mixtures is likely not going to have a meaningful effect.
The second is their choice of placebo. If I were to conduct a study to determine if my “fat loss” supplement were beneficial above and beyond conventional means I would have included an additional group where I dosed my placebo with equal amounts of caffeine as it is well documented that caffeine can exert lipolytic effects.
When participants took SHRED there was no significant effect on condition (SHRED or placebo) on pre or post workout fat oxidation. Their was a significant increased from Pre 1 to Pre 2, from Pre 2 to Post, and from Pre 1 to Post for SHRED. There was a significant increase in fat oxidation from Pre 1 to Post and from Pre 2 to Post in the placebo, but not Pre 1 to Pre 2.
SHRED did indeed reduce perceived exertion by roughly .5-1.0 points out of a 6-20 point scaled.
SHRED did not have any influence on heart rate. This result is counter to what we typically see with caffeine ingestion prior to exercise.
There was one time point (~30 minutes) where participants were more satiated. However the difference was extremely small (0.33 on a 10 point scale). It is likely it did not have a meaningful effect on hunger.
The authors open their discussion with the following statement.
“The present study is the first to demonstrate an acute effectiveness of a multi-ingredient supplement, SHRED-Matrix for exercise-related metabolic outcomes. Findings include an enhanced FAO during exercise combined with an enhanced perceived exertion and improved side-effects associated with satiety, often reported with weight-loss supplements”.
I find the first sentence a bit of a stretch. Yes, this SHRED product increased fat oxidation from Pre 1 to Pre 2 while placebo did not, but there was still no difference between the groups at any time point. I urge more caution in interpreting this data, such a broad statement on a small piece of data is likely inaccurate.
I find the second sentence entirely innacurate. They report ZERO data for fat oxidation (FAO) during exercise for the placebo and SHRED trials.
Now it is indeed likely that SHRED increases acute fat oxidation in small amounts above placebo (although the P values are not significant the way the data appears suggests it is possible). But given the well documented lipolytic effects of caffeine it is hard to know whether the other ingredients in SHRED make it superior to caffeine. We need a head-to-head comparison with equal amounts of caffeine.
Additionally we need to remember that acute increases in fat oxidation do not necessarily increase fat loss. In the event that future studies verify SHRED as an acute increaser of fat oxidation we still need long term studies before we know if it yields better body composition
What was clear in the data was that SHRED had some improvements in perceived exertion during exercise. So it might help with the fatigue aspect of training.
The Wrap Up.
SHRED does not appear to convey any robust, magical fat burning properties. Caffeine from coffee or caffeine pills is likely to give you the same marginal benefit of increased acute fat oxidation and reduced fatigue that might be present in the current study at a fraction of the cost.