With studies about the effects of “cumulative” or “continuous” cardio on body composition and health, a (re-)evaluation of post-strength-training cardio and its effects on your gains, and an investigation into the tendon weakening effects of CrossFit workouts, this installment of the SuppVersity short news has (hopefully) science news from the latest issue of the Scandinavian Journal of Medicine and Science in Sport that are of interest for you… and if it hasn’t, check out the SuppVersity Facebook News and subscribe to @SuppVersity on Twitter and/or Instagram.
Spread or grind – What’s better for your heart? Study compares continuous to intermittent accumulating cardio exercise (same daily volume, but either as 1×30-60 min or 3×10-20 min) and finds … “It depends” (Costa-Pereira 2017)
I have to admit: we’re talking about a rodent study, here, but it is indeed likely that humans would see a similarly different response to accumulating exercise vs. continuous exercise. If that’s indeed the case, you should
- split your training up to minimize body weight and fat gain, as well as inhibit visceral adipocyte hypertrophy, or,
- do a single longer cardio session to improving systolic blood pressure, LDL/HDL cholesterol, and serum triglyceride.
No matter what you choose, by the way, both endurance training protocols will increase heart function, decrease lipid peroxidation, and increase the intracellular Hsp72 content in the heart… well, at least if our supposition holds and the effects in humans are identical.
Conflicting evidence on “cardio interference” — HIITing it after your strength training workouts won’t mess with your gains latest study shows (Tsitkanou 2017).
As a regular SuppVersity reader, you will know that previous studies have (alternatingly) suggested that doing cardio after your workouts will/will not impair your gains. With the publication of Tsitkanou’s latest study, we’re back to the “will not impair your gains” side of things… at least for HIIT cycling that’s after a leg workout.
Figure 1: Cross Section Area (CSA) of each fiber type (I, IIA, IIX) before and after 8 weeks of resistance training only (RE, a), and resistance plus aerobic training (REC, b). *P < 0.05, **P < 0.01, §P < 0.001 difference between before and after training; the changes in muscle strength didn’t show treatment differences, either (Tsitkanou 2017).
If you scrutinize the data in Figure 1, you will even realize that the HIIT-cycling prompted extra increases in aerobic capacity and muscle capillarization. A benefit you probably won’t want to miss considering the fact that it doesn’t seem to come at the expense of decreased strength and size gains in response to a standardized leg workout with 4×6 reps to failure on the inclined leg press (45° angle) and the half-squat (knee angle 90°) Smith machine.
Eventually, more studies (and meta-analyses) will have to be conducted, though, to find potentially confounding variables which determine whether “cardio impairs your gains” or not… as of now, I have seen enough evidence to speculate, though that HIIT – here 10 sets of 60-s duration on a stationary bicycle with 100% of maximal aerobic power – may not be as much of a problem as longer duration medium intensity steady-state cardio.
CrossFit thickens your tendons — “A significant increase in the thickness of the patellar and Achilles tendons was found in response to strenuous, highly intense CrossFit exercises” (Fisker 2017)
Now you may be asking yourself: Wait a minute, is that a good or a bad thing? Well, the answer is obvious. It’s a bad thing, or as Fisker et al. explain: “[C]hronically overloaded tendons will thicken and increase the risk of tendinopathy.” The results of the scientists ultrasonography of the patella, Achilles, and plantaris tendons of 34 healthy subjects may thus provide reasons to worry for anyone following a similar CrossFit workout consisting of five rounds of five weighted front squats at 50 kg (males)/30 kg (females); 10 box jumps (jumping onto and down from a 60 cm (males)/50 cm (females) box), and 15 double unders (two rotations of a jump rope per jump).
Figure 2: Patellar, Achilles, and plantaris tendon thickness (mm) before and after workouts (Fisker 2017).
Despite being statistically significant, the observed changes in patella tendon (11%) and, even more so, the small increases in Achilles tendon thickness (2%) are everything but convincing evidence that CrossFitting entails a general risk of tendinopathy.
It is just as Fisker et al. write: “Further studies investigating the duration of these acute changes are needed as well as studies investigating the effects of intense overload, taking into account gender, age, race, skill level and physical fitness” (Fisker 2017). Plus: We should not forget that there was no “regular strength training” control… I bet there’ll be similar increases w/ any form of heavy lifting, which, in turn, begs the question: is that really a problem?
That’s it already? Well, sort of. There’s one study left in the latest issue of the Scandinavian Journal of Medicine & Science in Sports; a study that has its main (and somewhat disappointing) result in the title, already: “Chronic lactate supplementation does not improve blood buffering capacity and repeated high-intensity exercise” (Oliveira 2017).
Why do I even mention this study, then?
Well, the study had a bicarbonate group, as well … and guess what: Unlike lactate, which had no effect on either pH or performance, the provision of sodium bicarbonate (NaHCO3) triggered a 2.9% performance increase in overall total mechanic workload (P = 0.02) during standardized Wingate tests (four bouts) and an even more pronounced 5.9% performance increase in the 3rd+4th bouts (P = 0001)
Costa-Pereira, L. V., Melo, D. S., Santos, C. S., Mendes, B. F., Esteves, E. A., Lacerda, A. C. R., de Miranda, J. L., Rocha-Vieira, E., Gripp, F., Amorim, F. T., Magalhães, F. C. and Dias-Peixoto, M. F. (2017), Distinct beneficial effects of continuous vs accumulated exercise training on cardiovascular risk factors in Wistar rats. Scand J Med Sci Sports, 27: 1384–1394. doi:10.1111/sms.12737.
Fisker, F. Y., Kildegaard, S., Thygesen, M., Grosen, K. and Pfeiffer-Jensen, M. (2017), Acute tendon changes in intense CrossFit workout: an observational cohort study. Scand J Med Sci Sports, 27: 1258–1262. doi:10.1111/sms.12781
Oliveira, L. F., de Salles Painelli, V., Nemezio, K., Gonçalves, L. S., Yamaguchi, G., Saunders, B., Gualano, B. and Artioli, G. G. (2017), Chronic lactate supplementation does not improve blood buffering capacity and repeated high-intensity exercise. Scand J Med Sci Sports, 27: 1231–1239. doi:10.1111/sms.12792
Tsitkanou, S., Spengos, K., Stasinaki, A.-N., Zaras, N., Bogdanis, G., Papadimas, G. and Terzis, G. (2017), Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy. Scand J Med Sci Sports, 27: 1317–1327. doi:10.1111/sms.12751