 |
| If you want to show off your "guns" cold water immersion (CWI) may be counterproductive in the short- and long-run. In the hours and days after the workout, you'll miss the swelling, over weeks you'll blunt 'ur gainz. |
This paper, alongside the latest research on the ergogenic effects of capsaicin supplements on short-medium distance running and the surprisingly position-depending inaccuracy of multi-frequency bioimpedance measurements of the body composition of collegiate football players, are the studies discussed in today's installment of "On Short Notice".
Read about exercise- and nutrition-related studies in the SuppVersity Short News
![]()
Alcohol, Microbes & International Chest Day![]()
Aug '15 Ex.Res. Upd.: Nitrate, Glycogen, and ...![]()
Pre-Exhaustion Exhausts Your Growth Potential![]()
HbA1c, Bone Health, BFR & More | Jan'17![]()
TeaCrine®, ALA, Tribulus, Cordy-ceps, Sesamin...![]()
The Latest Fiber & Microbiome Research
Alcohol, Microbes & International Chest Day
Aug '15 Ex.Res. Upd.: Nitrate, Glycogen, and ...
Pre-Exhaustion Exhausts Your Growth Potential
HbA1c, Bone Health, BFR & More | Jan'17
TeaCrine®, ALA, Tribulus, Cordy-ceps, Sesamin...
The Latest Fiber & Microbiome Research
- Cold water immersion (CWI) shuts off PWO inflammation in biceps muscle (Matos 2017) -- A recent study by Matos et al. 2017 highlights once more the potency of cold water immersion (CWI) as a useful acute treatment to prevent post-workout inflammation. A good thing if you have to compete again in the next 24h, but - as previous research showed - a double-edged sword when it comes to the adaptational processes to exercise, i.e. the "training effect", which is blunted when the regular inflammatory process is disturbed or inhibited.
In the corresponding experiment, the Portuguese scientists tried to verify the effects of CWI on muscle swelling by measuring the muscle thickness (MT) of their subjects' elbow flexors after a standardized resistance training protocol (RT).
Eleven males were submitted to an RT (see Figure 1), performed in two different weeks. In one of the weeks, subjects experienced a passive recovery. In the other, subjects were submitted to a CWI (20 min at 5-10°C). Ultrasound (US) images were taken pre-, post-, as well as 24h, 48h and 72h post-exercise, to evaluate the MT.![]()
Figure 1: Graphical illustration of the study design (Matos 2017).
The results were simple: CWI works and it does so pretty well. The muscle thickness of both exercise (RT) and control (CA) arm was significantly higher 48h and 72h post-exercise when subjects were submitted to a passive recovery compared with the CWI (p=0.029, p=0.028 and p=0.009, p=0.001, 48h, 72h, EA and CA, respectively). The swelling was not, however, blocked completely (the trained arm was still thicker than the untrained one).
Accordingly, the study at hand confirms the usefulness of CWI as a means to reduce muscle swelling and the associated potential performance impairments. It does yet also reinforce the idea that CWI may blunt the normal inflammatory response to resistance training which would, in turn, explain why previous studies observe a significant negative effect of repeated use of CWI on strength and size gains in response to a standardized resistance training regimen.![]()
Figure 2: Muscle swelling of the biceps before and after the test-workouts w/ CWI or passive recovery; percentages across the bars indicate the relative difference between CWI and no CWI trial (Matos 2017). - More evidence in favor of the performance-enhancing effects of capsaicin (de Freitas 2017) -- As a SuppVersity reader, you will know that capsaicin, which has long been marketed solely as a thermogenic fat burner, has recently been found to have ergogenic effects, as well. In a new study, de Freitas, Cholewa, Gobbo, de Oliveira, João, Lira, and Rossito investigated the acute effect of capsaicin supplementation on the performance, rate of perceived exertion and blood lactate concentrations during short duration running in physically active adults.
Ten physically active men (age= 23.5+/-1.9 yrs, weight= 78.3+/-12.4 kg, height= 177.9+/-5.9 cm) completed two randomized, double-blind trials: Capsaicin condition (12 mg) or a placebo condition. Forty-five minutes after supplement consumption, the participants performed a 1500 meter running time trial. Time (in seconds) was recorded. Blood lactate concentration was analyzed at rest, immediately post-exercise, post-5, 10 and 30 minutes during recovery and the rate of perceived exertion (RPE) was collected after exercise.
As you can see in Figure 3, "[t]he time was significantly (t= 3.316, p= 0.009) lower in the capsaicin (371.6 + 40.8 sec) compared to placebo (376.7 + 39 sec). RPE was significantly (t= 2.753, p= 0.022) less in the capsaicin (18.0 + 1.9) compared to the placebo (18.8 + 1.3).![]()
Figure 3: 1.5k Time trial performance and rate of perceived exertion in placebo vs capsaicin trial (de Freiatas 2017).
In view of the lack of effect on lactate levels, which increased over time for both conditions without significant differences between (p>0.05) and considering the short timeframe of the exercise intervention it is unlikely that this performance increase is a result of an increase in fat oxidation as it has been observed in mouse and man (Inoue 2007) in response to the ingestion of capsaicin before. - Multi-frequency bioelectrical impedance analysis (MfBIA) is not an accurate measure of body composition in collegiate football players (Raymond 2017) -- If you own a body fat scale, you will be aware that the absolute body fat values these devices calculate based on the resistance your body offers to the current that's running from your left to your right foot or vice-versa are not exactly reliable (I wish I was at the 5% body fat my scale tells me I had left ;-).
Accordingly, the conclusion that "MfBIA does not appear accurate in examining between-player body composition in college football players" (Raymond 2017) probably won't surprise you. The reason you may find Christiana Raymond's latest study still interesting is not that it shows the inefficacy of BIA measurements, anyway. Rather than that it allows us to draw some conclusions about whose values are going to be particularly messed up, because her study is the first to also examine the influence of player position (and thus built) on the agreement between multi-frequency bioelectrical impedance analysis (MfBIA) and dual X-ray absorptiometry (DXA) when assessing total and segmental percent body fat (BF%), fat mass (FM), and fat-free mass (FFM) in NCAA Division I collegiate football athletes.
For the study, forty-four male collegiate athletes (age=19+/-1 yrs; height=1.9+/-1.0 m; weight=106.4+/-18.8 kg) were recruited. Player positions included: offensive linemen (OL; n=7), tight ends (TE; n=4), wide receivers (WR; n=9), defensive linemen (DL; n=6), defensive backs (DB; n=8), linebackers (LB; n=6), and running backs (RB; n=4). Total and segmental body composition measured using MfBIA were compared with values obtained using DXA.![]()
Figure 4: It's not just the body fat percentage that differs according to a player's position. The average length of an NFL carreer also differs by position w/ wide receivers having the shortest and offensive lineman the longest careers (data from pro-football-reference.com, originally published in "The Wall Street Journal")
Compared to DXA, MfBIA underestimated BF% (3.0+/-3.8%), total FM (2.5+/-4.3 kg), arm FM (0.4+/-0.8 kg), arm FFM (1.4+/-0.9 kg), leg FM (2.8+/-2.0 kg), and leg FFM (5.4+/-2.4 kg) (all p<0.001; arm FM p=0.002) and overestimated total FFM (-2.4+/-4.5 kg) (p<0.001). Limits of agreement (LOAs) were: +/-7.39% (BF%), +/-8.50 kg (total FM), +/-1.50 kg (arm FM), +/-1.83 kg (arm FFM), +/-3.83 kg (leg FM), +/-4.62 kg (leg FFM), and +/-8.83 kg (total FFM).![]()
Figure 5: Difference of DXA - MfBIA-measured body composition by player position (Raymond 2017).
Beware: BIA systematically underestimates body fat and overestimates lean mass
In that there's yet also good news: There was no significant difference between devices for the health-relevant trunk FM (-0.3+/-3.0 kg; p = 0.565) and trunk FFM (0.4+/-2.4 kg; p=0.278), with LOAs of +/-5.92 kg and +/-4.69 kg, respectively.
Most importantly, however, the researchers found that the "player position significantly affected all between-device mean body composition measurement differences (adjusted p<0.05), with OL demonstrating the greatest effect on each variable" (Raymond 2017) - an observation the scientists from the University of Minnesota interpret in the previously cited way: "MfBIA does not appear accurate in examining between-player body composition in college football players" (Raymond 2017).
 |
| Choline Supplementation Accelerates Fat Loss During Crash Diet in Female Athletes: 2g Choline Double the Rate of Fat Loss in the Last Week Before the Competition | more |
As I've pointed out in relation to previous studies on the accuracy of body impedance analyses, this does not necessarily mean that you have to trash your body fat scale - you will still be able to track your progress, just ignore the absolute value and make sure you always measure well-hydrated and at the same time of the day | Comment!
- de Freitas, et al. "Acute Capsaicin Supplementation Improves 1500 M Running Time-Trial Performance And Rate Of Perceived Exertion In Physically Active Adults." Journal of Strength & Conditioning Research: Post Acceptance: November 06, 2017. doi: 10.1519/JSC.0000000000002329
- Inoue N, Matsunaga Y, Satoh H, Takahashi M. Enhanced energy expenditure and fat oxidation in humans with high BMI scores by the ingestion of novel and non-pungent capsaicin analogues (capsinoids). Bioscience, biotechnology, and biochemistry. 2007 Feb 23;71(2):380-9.
- Matos, Filipe; et al. "Effect Of Cold Water Immersion On Elbow Flexors Muscle Thickness After Resistance Training." Journal of Strength & Conditioning Research: Post Acceptance: November 06, 2017. doi: 10.1519/JSC.0000000000002322
- Raymond, Christiana J. M.S.; et al. "Total And Segmental Body Composition Examination In Collegiate Football Players Using Multifrequency Bia And Dxa." Journal of Strength & Conditioning Research: Post Acceptance: November 06, 2017. doi: 10.1519/JSC.0000000000002320