Showing posts from 2014

Phosphatidylserine: Where's the Research?

Seeking the truth? Do not strive to prove, but to disprove. From my perspective, the increasing popularity of phosphatidylserine (PS) as an ergogenic aid is entertaining. When a new supplement hits the market with claims of improved performance, increased this, decreased that... The "gurus" want a piece of the action - they jump on the bandwagon; like they've known all along. Now they're giving dosing protocols, touting the supposed benefits of "the next big thing." PS is not a new supplement - you can find research on PS and exercise dating back to the 80's. It used to be obtained from bovine cortex (cow brains), but after the mad cow disease scare, it has more recently has been extracted from soy (Jager et al., 2007). If you rely on the gurus' supplement reviews or forums for your nutrition information, you may be on your way to the nearest supplement shop. But before we get carried away, I have a few thoughts and questions about PS:

Altitude Acclimation: Potential Application for Improved Exercise Economy

The "big three" determinants of endurance exercise performance are VO2max, pH threshold (sustainable pace) & exercise economy. We could also include anaerobic capacity and maximal speed/power as components that could determine the outcome of a sprint finish. The importance of running economy has been documented many times, and is often regarded as a strong predictor of performance, especially between individuals with similar VO2max values (Saunders et al. 2004; Daniels 1985). I've written on training for economy in the past. Training strategies such as hill sprints, resistance training, plyometrics or high intensity intervals have all shown improvements in economy.  In two studies, Saunders et al. (2004, 2009)  have also shown improvements in running economy following altitude acclimation. A study by Czuba et al. (2014) produced similar results in elite level biathletes and Latshang et al. in mountaineers (2013). Potential mechanisms? Stays at altitude are

Training for Endurance: Progressive Recruitment

I read  an article on VeloNews  a while back describing how many cycling races are won and lost in the final hour or minutes of racing. And this is generally true, it often comes down to who can sustain the highest power output in the final push to the finish after three, four, or five+ hours in the saddle. Rationally, it makes sense that being able to delay fatigue and enter that last hour of racing with a greater capacity for work will enable an athlete to finish faster. Many of this spring's one day classics have served prime examples - those that produce the greatest amount of power in the end will prevail. Take this years's  Milan-San Remo  for example: after 6 hours of riding, the race hits a series of small climbs before a sprint to the line. This year, it was Alexander Kristoff in the final sprint (after nearly 7 hours on the bike) who took the win - out-sprinting the likes of Mark Cavendish and Fabian Cancellara. When asked about the finish, Kristoff acknowledged that

Are we on a Quest for Mitochondria or a Quest for Maximized Performance?

What I don’t understand is when I see teams and athletes pursuing marginal gains and ignoring the basics and fundamentals of sound training. There is no sense pursuing the last 2% until you have taken care of the first 98%. -Vern Gambett a As science advances, we identify transcription factors and map cellular signalling pathways in clinical settings to potentially maximize muscles' oxidative capacities. While mitochondrial biogenesis and angiogenesis are undoubtedly important for improving a muscle fiber's resistance to fatigue, we have to ask - should these be the target or the byproduct of training? In other words, is it practical and worthwhile for athletes to manipulate their environments and diets in search of additional stress? What effect might this have on performance? An interesting review has been published recently: Link Here The review from Baar is focused on using the available molecular knowledge to potentially maximize the activity and number of PGC-1a t

Endurance Training: Running vs. Cycling

A lot of people ask me, "What's the biggest difference between training for running and training for cycling?" The simplest answer is that an athlete should have so much more opportunity to suffer on the bike. If a runner's training not limited by time, motivation, or illness; what is it limited by? It's fatigue and the ability to recover from previous workouts. If recovery was not a limiting factor, he could go out and run 3+ hours, or complete intervals at 5K race pace day after day without the fear of injury or exhaustion. What about the cyclist? Yes, fatigue is a real thing for the cyclist; but mechanically, cycling is very different from running. During cycling an athlete experiences very few eccentric muscle contractions. Meanwhile, the runner is constantly subjecting his quadriceps, hamstrings, hip and plantar flexors to impact forces and eccentric muscle contractions. These eccentric contractions cause muscle damage, in turn causing muscle sorenes

Uncoupling Proteins, Metabolism, Economy

What if I said, overweight people have the potential to be very good endurance athletes. Or you could say; very good endurance athletes are especially susceptible to becoming overweight when they're no longer training for competition. Well, this is largely rooted in speculation, but for curiosity's sake - stay with me. The theory is based on mitochondrial efficiency, or how well the electron transport chain can create and maintain a H+ concentration gradient across the inner mitochondrial membrane. This concentration gradient is used to drive ATPsynthase to generate ATP. If you had a leaky membrane and you were losing hydrogen ions, you'd be losing that gradient you worked so hard to create. Like trying to fill a bucket with a hole in the bottom, you'd have to turn up the water (substrate) to get it to fill up. Uncoupling proteins essentially act as holes in the mitochondrial membrane, allowing protons to pass through them without harnessing their potential energy

Concurrent Training: Training Order

I've expressed my opinion several times - separate the two when the goal is either strength or endurance But if you're into combining them into one workout, recent research ( link here ) indicates that performing strength training after endurance training results in the more favorable endocrine response than strength before endurance. Be careful with this information, as no performance measures were taken. While strength training after endurance training resulted in higher serum concentrations of  testosterone and IGFPB-3, it would be irrational to assume that this results in the greatest performance gains - and at what performance measures: strength vs cardiovascular endurance. At the end of the day, more work completed = more muscle damage and more energy expended.

pH Threshold: More Useful than Lactate

Lets's imagine we have a race or time trial coming up. Maybe it's an 8K run, maybe it's 20K on the bike. But we expect the time trial to last 26-28 minutes. Now, what will be the physiological governors of our performance? We could create a long, long list or flow chart of factors that govern exercise performance. But in the simplest sense, it comes down to the maximum sustainable power (work/time) that an athlete can generate for the given race duration. The more power, the faster the time trial (less time) and vice versa.  So, what governs maximum sustainable power? Here again, a number of factors (VO2max, substrate availability, economy, a central governor?). Assuming these factors are consistent, what about lactate threshold? For years coaches and physiologists have been proclaiming lactate threshold to be the maximum sustainable pace or power for race distances of ~60:00. Assuming above this threshold, lactate accumulates exponentially and associated

The "Lactate Paradox"

Lower peak lactate levels at high altitudes Oxidative phosphyorlation is a consumer of NADH + H+. But at altitude or under hypoxic conditions, an individual's ability to utilize oxidative phosphorylation is negatively affected by the decreased availibility of O2. Consequently, NADH + H+ accumulates and acidosis occurs. H+ accumulation inhibits glycolysis. Inhibition of glycolysis = decreased pyruvate and lactate production. Further, at altitude respiration rate increases at rest. This increases blood pH. This increase in pH at rest causes bicarbonate to be excreted from the kidneys. Loss of bicarbonate reduces the athlete's ability to buffer H+. H+ accumulation ---> acidosis ---> inhibition of glycolysis ---> decreased lactate production. Again, could supplementation with beta-alanine limit acidosis, offset the lactate paradox, and maintain work capacity at altitude?

Quick Read: Muscle Damage and Running Economy

Interesting research concerning running economy and muscle damage from researchers (and runners) at Georgia State: Last year, a colleague and I tried to collect some pilot data assessing ankle jerk/patellar reflexes and running economy following a brutal eccentric workout (drop jumps and leg press). The reflex results were unclear and a broken treadmill threw a wrench into our running economy analysis... What implication(s) could this have for athletes? It would be wise to avoid muscle damage (downhill running, eccentric resistance training) in the 2-3 days before major competitions. Could cross training that elicits less muscle damage than running (cycling, elliptical, swimming) in the days immediately prior to a race increase running economy? Of course, if you have a race coming up that has a substantial amount of downhill, you may be able to attenuate some of the muscle damage that would be attained during the race by consistently

Snake Oil

I was at Rite Aid yesterday picking up a few items and I happened to walk down the "Sports Nutrition" aisle. One product in particular caught my eye, in part, due to its outrageous price tag. Alphatest from Muscletech is supposedly a "Super-Concentrated Performance and Testosterone Stimulant." The bottle makes the claims, "Anabolic, Anti-Catabolic, Performance." Well first off, if something is anabolic, by nature, it has to be "anti-catabolic." These supplements always make me wonder... Who comes up with this stuff? It's like they have a list of 10 key words that they have to choose from to put on the bottle. For demonstration purposes only, I took photos of the product (shown below). I certainly do not endorse MuscleTech, and I cannot acknowledge any conflicts of interest. Looking past the ridiculous name, claims, and price tag; what do we actually have in Alphatest? Here again, we have to look beyond the bombastic rhetoric

Run Training for the Multisport Athlete or Injury Prone Runner: Theory and Application

We've seen crossover fitness gains from cycling transfer to improved or maintained running performance in the past (White et al., 2003; Millet et al., 2003; Ruby et al., 1996; Etxebarria et al., 2013). So, I want to propose a method of training to maximize running performance for runners or multisport athletes who, for whatever reason, cannot handle high volumes of running. Most physiologists will agree that running performance is determined by the following three or four physiological factors: VO2max, lactate threshold, anaerobic capacity, and running economy (RE) (Midgley et al., 2007). Of course, psychology, motivation, and a central/peripheral governor may also play a role, but I want to focus solely on the trainable physiological factors. The Scenario:  An athlete is returning from a tibial stress fracture sustained during a high-mileage "base phase" in the month of December. This is the athlete's third tibial stress fracture in four years that can be attrib

Marathon Training Specificity: At What Cost?

Marathon training... it can quickly become a complex beast. Chose your running website of choice or do a quick search for training plans and you'll end up with all sorts of ideas and theories (including this one). I would venture to say that the common theme between the marathon training plans you'll find is higher volumes and relatively lower intensities when compared to a 5K or 10K program. But have you ever stopped to ask, "Why?" Why should an athlete need 20+ mile long runs and 80+ mile weeks? Why should an athlete complete 10 mile tempo runs instead of repeat 400s? Well, I like to ask questions... A couple of weeks ago, after helping give a class presentation on the dominance of East-African runners, one of my classmates made the comment that we, as "sports-scientists", tend to over-analyze th ings. She argued that instead of trying to figure out what makes some athletes better than others, we should just go back to the basics and focus on what

Beta-Alanine - Past and Future

Around 2009, I discovered the supplement beta-alanine and at that time I was intrigued by something that could potentially improve H+ buffering capacity and exercise performance. In the summer of 2011, I went to a symposium at the ACSM's annual meeting that discussed (as well as promoted PowerBar's) beta-alanine supplementation for performance enhancement. Below is a presentation I gave later that summer as an intern at Carmichael Training Systems. Since 2011, we've had more literature published and I'll try to discuss a few of those below the posted presentation as well as provide some food for thought and suggestions for future research. In short - beta-alanine supplementation has consistently shown that it increases carnosine in skeletal muscle and carnosine is understood to be an effective intracellular buffer. What's not clear is if that leads to increases in performance - but there is potential. Since the time of this presentation, we've had