|Welcome to today’s installment of “on short notice”|
You may remember from the SuppVersity news on Facebook that the use of cobalt supplements can indeed (as it has long been touted and doubted) have similar effects as EPO (Hoffmeister 2018). Yet while the study by Hoffmeister et al. showed that the VO2max correlated significantly with the 2% increase in Hemoglobin in response to the ingestion of 5 mg of ionized Co2+ for 3 weeks, an acute performance-enhancing effect was neither tested nor observed in the German study.
That’s in contrast to autologous (=your own) blood infusions. A simple injection of only ~135 ml of red blood cells that were previously isolated from 450 ml of your own blood 2h before training or competition will improve your endurance performance by 5%, … according to the latest study from the University of Copenhagen (Bejder 2018).
And if you’re rather into lifting weights than cycling, running, or triathlons, today’s research update also discusses the results of a recent small-scale study by Malovany et al. (2018), which puts a(t least a preliminary) number on the usefulness of escalating post-workout protein intakes from high to very high. Sounds interesting? Well, then let’s start with the “blood doping” study by Bejder, et al.
- Instant (2h post) 5% performance boost in athletes w/ 135 ml of red blood cells (#RBCs) from a single 450 ml phlebotomy (Bejder 2018) — While you all will have heard about “blood doping” and the infusion of autologous (=their own) blood and/or isolated red blood cells (#RBCs) in cyclists and other endurance athletes, I bet that you will be as surprised as I was that a single injection of 135 ml of red blood cells (#RBC) from a rather small amount of your own blood (450 ml) will improve your endurance performance by 5% – and that only 2h after you injected the RBCs.
- Study type: Randomized, double-blind, placebo-controlled crossover study
- Comparison: placebo = sham phlebotomized vs. blood transfusion-trial
- Subjects: N=9 (=small scale) young men w/ >1year resistance training (all major muscle groups | training at least twice a week) experience who didn’t do more than 30 minutes “cardio” per exercise session and were able to life 0.7x and 2.3x their bodyweight on the bench press & leg press, respectively; no supplement use, general health, you know it…
- Outcomes: Hb, Hct, RBC, and Ret% 1wk before phlebotomy, 3 days before transfusion, 2 h post 135 ml transfusion and 3 days post 135+235 ml transfusion
- Performance tests: (1)Two 650kcal time-trial three days and 2h after receiving either ~50% (135 ml) of the RBCs or a sham transfusion on subsequent days + (2) One 4×30 s all-out cycling sprint interspersed by 4 min of recovery was performed six days before and three days after a second autologous blood transfusion (235 ml).
- What the scientists found was that the subjects’ mean power in the time trial (TT) to was increased in time trials from before to after transfusion (P<0.05) in BT (213±35 vs. 223±38 W; mean±SD) but not in PLA (223±42 vs. 224±46 W | see Figure 1, left).
Figure 1: Mean power in the TT and during the 4x30s sprints in the active and placebo trial (Bejder 2018).
For the four 30 s sprint bouts that were performed not 2h, but three days later no effect was observed [BT (639±35 vs. 644±26 W) and PLA (638±43 vs. 639±25 W) | see Figure 1, right].
+ + + The “protein ceiling” study + + +
- Optimal post-workout protein intake for max. protein synthesis over 8h in resistance-trained women is 1.5-2.0g/kg – More will just be burned as fuel (Malovany 2018) — For men we’ve known this all along: There’s a threshold value not to how much protein we can in- and digest in one serving, but rather to the amount of protein that can be used to fuel skeletal muscle protein synthesis after workouts (Humayun 2007; Jäger 2017). And while they certainly have to be considered preliminary due to the small sample size of N=9, Malovany et al.’s (2018) latest study shows that a similar threshold exists for female resistance trainees, too.
- Study type: randomized sequential study of the effect of different amounts of PWO protein ranging from deficient to excess (0.2-2.90 g/kg)
- Subjects: N = 8 healthy females w/ regular menstrual cycles, who perform whole-body resistance exercise regularly, had trained each major muscle group (i.e., chest, back, and legs) at least twice per week consistently for at least one year prior to recruitment, didn’t do more than 30 min of continuous endurance training per exercise session, and whose 1RM on the bench press and leg press of 0.7 and 2.3 × bodyweight, respectively.
- Outcomes: steady state whole body phenylalanine rate of appearance (Ra), oxidation (Ox; the reciprocal of protein synthesis, PS) and net protein balance protein synthesis measured via minimally-invasive indicator amino acid oxidation (IAAO) technique (protein synthesis) and urinary Urea: Creatinine ratio (protein oxidation), respectively
- Exercise standardization: 2d prior to each metabolic trial, all participants were required to complete a prescribed but self-monitored whole-body resistance exercise session – the workout was identical to the workout they would do on the test day, i.e. i) barbell bench press, lat pulldown superset; ii) standing overhead barbell press and seated cable row superset; iii) leg press; and iv) leg extension; each exercise was performed at 75% 1RM for 4 sets of 8-10 repetitions with ~90s rest intervals between sets
- Dietary standardization: 2-d adaptation diet containing 1.2 g/kg/d of protein during the 2-d controlled training period prior to each metabolic trial
- Testing days: ingestion of liquid carbohydrate beverage (1 g/kg as a 1:1 ratio of maltodextrin: Gatorade® Endurance) 1h before std. workout (see exercise standardization); each participant completed 6-7 metabolic trials (n = 50 for total trials completed) during the luteal phase, which was defined as the second half of the menstrual cycle.
- Supplementation: 8x hourly meals providing a randomized test protein intake (0.2-2.9 g/kg) as crystalline amino acids, modeled after egg protein, with constant phenylalanine (30.5 mg/kg) and excess tyrosine (40.0 mg/kg)
- As you can see in Figure 2 (left), the scientists observed a ceiling effect for the protein synthesis with protein intakes >1.5g/kg body weight – the horizontal nature of the linear trend for the values clearly indicates this.
The rate of protein oxidation, which was estimated via the urinary Urea: Creatinine ratio, on the other hand, increased linearly with increasing protein intakes (Figure 2, right) – without a threshold effect, i.e. the more protein, the more is going to be oxidized (see bottom line for discussion of what would happen w/ bolus vs. 8×1/h ingestion).
- Bejder, J. “Time Trial Performance Is Sensitive to Low-Volume Autologous Blood Transfusion.” Medicine & Science in Sports & Exercise: November 6, 2018 – Volume Publish Ahead of Print
- Hoffmeister, Torben, et al. “Effects of 3 weeks of oral low-dose Cobalt on hemoglobin mass and aerobic performance.” Frontiers in physiology 9 (2018).
- Humayun, Mohammad A., et al. “Reevaluation of the protein requirement in young men with the indicator amino acid oxidation technique–.” The American journal of clinical nutrition 86.4 (2007): 995-1002.
- Jäger, Ralf, et al. “International society of sports nutrition position stand: protein and exercise.” Journal of the International Society of Sports Nutrition 14.1 (2017): 20.
- Malowany, Julia M., et al. “Protein to Maximize Whole-Body Anabolism in Resistance-trained Females after Exercise.” Medicine & Science in Sports & Exercise (2018).