Research Review

Saunders MJ, et. al. Effects of a carbohydrate-protein beverage on cycling endurance and muscle damage. Med Sci Sports Exerc. (2004) 36(7):1233-8.

INTRODUCTION: The purpose of this study was to determine whether endurance cycling performance and postexercise muscle damage were altered when consuming a carbohydrate and protein beverage (CHO+P; 7.3% and 1.8% concentrations) versus a carbohydrate-only (CHO; 7.3%) beverage. METHODS: Fifteen male cyclists (mean (.-)VO(2peak) = 52.6 +/- 10.3 mL x kg x min) rode a cycle ergometer at 75% (.-)VO(2peak) to volitional exhaustion, followed 12 - 15 h later by a second ride to exhaustion at 85% (.-)VO(2peak). Subjects consumed 1.8 mL x kg BW of randomly assigned CHO or CHO+P beverage every 15 min of exercise, and 10 mL x kg BW immediately after exercise. Beverages were matched for carbohydrate content, resulting in 20% lower total caloric content per administration of CHO beverage. Subjects were blinded to treatment beverage and repeated the same protocol seven to 14 d later with the other beverage. RESULTS: In the first ride (75% (.-)VO(2peak)), subjects rode 29% longer (P < 0.05) when consuming the CHO+P beverage (106.3 +/- 45.2 min) than the CHO beverage (82.3 +/- 32.6 min). In the second ride (85% (.-)VO(2peak)), subjects performed 40% longer when consuming the CHO+P beverage (43.6 +/- 12.5 min) than when consuming the CHO beverage (31.2 +/- 8.7 min). Peak postexercise plasma CPK levels, indicative of muscle damage, were 83% lower after the CHO+P trial (216.3 +/- 122.0 U x L) than the CHO trial (1318.1 +/- 1935.6 U x L). There were no significant differences in exercising levels of (.-)VO(2), ventilation, heart rate, RPE, blood glucose, or blood lactate between treatments in either trial. CONCLUSION: A carbohydrate beverage with additional protein calories produced significant improvements in time to fatigue and reductions in muscle damage in endurance athletes. Further research is necessary to determine whether these effects were the result of higher total caloric content of the CHO+P beverage or due to specific protein-mediated mechanisms.

My comments: Although this is an older study (2004), I think it's interesting to follow up on last week's abstract about carbs/protein during resistance training. More importantly, nothing very interesting came up on Pubcrawler this week.

For years, endurance athletes have been concerned with two primary factors during training: carbohydrates and hydration. We might add issues related to mineral balance although that's really only a huge issue for extremely long-duration events.

However, with recent research indicating a potential benefit of protein with carbohydrates after endurance training, there has been some interest in whether or not protein consumed during endurance training can affect performance or recovery. Unlike resistance training, protein can contribute to energy production during endurance training, with the branched chain amino acids (BCAA) being utilized directly for energy; this occurs to a greater degree when muscle glycogen is or becomes depleted.

This study gave a carbohydrate protein solution during an exhaustive endurance ride with an additional drink given immediately after training. For a 70 kg athlete, the drink would have provided 37 grams of carbohydrate and 9 grams of protein (a 4:1 ratio of carbs:protein) per hour and this was sipped in 15 minute intervals during the ride; the post workout drink contained an additional 51 grams of carbs and 13 grams of protein. The other group got only the carbohydrates. This means that the carb/protein group got slightly more calories during the workout.

In the first ride, the cyclists rode to exhaustion at 75% of VO2 max, 12-15 hours later they completed a second ride to exhaustion at 85% VO2 max.

The researchers made a number of interesting observations. First was that the time to exhaustion was significantly longer in the carbs/protein group compared to the carb only group in both the first and second ride.

Of possibly more interest, levels of creatine phosphokinase (CPK), a marker of muscle damage was significantly higher in the carb only group compared to the carb/protein group at the end of the first ride. This suggests that one of the mechanisms by which the carb/protein drink worked was to reduce muscle damage during the first ride. Clearly this has important implications for endurance athletes involved in daily or near daily exhaustive exercise; consuming carbohydrate and protein during endurance training may limit muscle damage and improve recovery on a day to day basis.

Any endurance athletes reading this newsletter could readily duplicate this study by using a commercial sports drink such as Gatorade or Powerade and adding a small amount of whey protein to it. A carbohydrate intake of 30-60 grams of carbs per hour is about the maximum that the gut can handle and, at a 4:1 ratio, a protein intake of 8-15 grams of protein per hour is all that would be necessary. Commercial products such as Accelerade are also available but tend to be more expensive than the do it yourself version.

From personal experience, chocolate whey protein goes terribly in fruit punch Gatorade (it tastes like ass), but is tolerable in orange. An unflavored or vanilla whey powder would probably work better from a taste standpoint.

Exercise of the Month

Deadlift variations Part 1

RDL, SLDL and conventional DL compared

Due to the amount of information I want to cover regarding deadlifts, I'm going to divide this month's exercise of the month into two parts. This month I want to compare and contrast a conventional clean-style deadlift (DL), the stiff-legged deadlift (SLDL) and the Romanian deadlift (RDL). There seems to be some ongoing confusion on some boards regarding the differences between these movements and the RDL and SLDL are often incorrectly equated.

Next month I'll go into more detail regarding technique for both clean style and sumo style deadlifts, since there's a lot to cover.

First let's look at the differences between the RDL and SLDL since they tend to be readily confused. Both movements start from the top with the bar held with straight arms and the torso upright. A double overhand, mixed, or hook grip can be used, straps are also a possibility.

From that point on, the similarities end. In the SLDL, the bar moves out in front of the body (the legs generally stay locked and the hips don't move) and the bar is generally brought quite low, usually to the instep of the shoes; this usually necessitates standing on a high platform so that the plates don't hit the ground. The back will be very rounded at the bottom of the movement. Lifting the bar is simply a reversal of the lowering, the low back unrounds as the lifter's torso comes back to the upright position.

In contrast, with the RDL the back remains flat or slightly arched, the knees are typically bent slightly (about 10-20 degrees) and the hips move backwards with the shins staying more or less vertical, the weight should be back on the heels.

A side by side comparison of the bottom position of the SLDL (left) and RDL (right) appears below.

SLDL bottom position

RDL bottom position

In the RDL bar is only lowered as low as the lifter can go without rounding the low-back, for most people this usually puts the bar just below the kneecap; I've seen the very occasional person with freak hamstring flexibility go lower and keep their back flat. Extremely inflexible lifters will stop higher and the RDL can actually be used as an excellent hamstring stretch (with just the bar or a small amount of weight). The upper back should be set and locked during the entire movement with the lats flexed (this will improve low back stability) and the shoulder blades pulled back, the bar should basically slide down the legs and over the knee. As the bar is lifted, it slides back up over the knee and then back up the thighs.

The below two pictures show a proper depth RDL (left) with the lifter having gone a little bit too low (right). Note how there is flexion in the lower back area with no change in hip position.

RDL bottom position

RDL too low

An easy way to avoid rounding the low back is to keep the head up (and neutral to your torso, don't hyperextend your neck) with the movement done in front of a mirror. If you can still see yourself in the mirror, your head is up and your low back shouldn't be rounded; if you can't see yourself anymore, you've dropped your head and have rounded either your upper or lower back or both. If you feel the tension come off of your hamstrings and into your low back, you've probably rounded your back as well.

For the most part, I'm not a big fan of the SLDL except as a light stretching or warmup exercise. The problem is this: as the low back rounds, the low back muscles (spinal extensors) become inactive due to an inhibitory reflex; this throws all of the stress onto the ligaments of the spine. As well, spinal flexion under load can be damaging to spinal disks in the long-run, increasing the risk of disk herniation. While I know many have done heavy SLDL's over the years, I can't recommend this based on what we know about spinal health.

Basically, I think that the RDL is the superior movement here. Olympic lifters use it as an assistance exercise (to mimick the second pull) and it can be done with either a clean or snatch grip, athletes and powerlifters use it to strengthen the posterior chain, and bodybuilders can use it to hammer their hamstrings. Basically, I think it's safer (from the standpoint of spinal health) and a more effective movement in the long-term.

Ok, next up is the normal DL which I'm only going to present briefly to compare it to the previous two movements. Unlike the previous two movements, the DL starts from the floor and involves movement at the knee, hip and even slightly at the ankle. This gets the quads, glutes and hamstrings all involved, in addition to working the low back and upper back. The lifter breaks the bar off the floor by using the lower body muscles and, initially, the torso should stay at the same angle. As the bar comes over the knees, the lifter starts to extend at the hip and straighten up, this is what's happening in the picture on the right; the bar has cleared the knees and the lifter is starting to extend at the hip to stand up with it.

The movement finishes (right picture) with the lifter standing up completely with the bar, having extended the hip completely and straightened the knees; the torso is upright with the shoulders pulled back.

Again, I'm not going to get into a full technique discussion for the conventional DL this month, you'll have to hang around 4 weeks until next month for that. Hopefully, this brief overview has given you an understanding of the primary differences between the RDL, SLDL and conventional DL.

DL Start

DL Finish

DL Middle

Questions and Answers

Q: Hi, I've been using a cyclical ketogenic diet for a few years now. When I increase calories in the form of fat in an effort to build mass, I do go up in strength and size but my gut follows. It gets to the point where I am too fat that I cut down on my fat intake and I start shrinking - muscle, fat and strength. At the point I do this, often I have plateaued anyway. To put the mass back on I have to do it all over again.

I'll give you an example workout routine i follow-

Mon- chest/back/abs

Tue - 20 mins cardio in form of heavy bag training, skipping

Wed - legs

Thu - off

Fri- arms/abs/shoulders

Sat - 20min cardio in form of sprints/jog

What am i doing wrong?

A: I don't like your workout very much, I think naturals should train a bodypart a minimum of once every 5 days; a bodypart frequency of 2X/week (or even 3X/week in the case of something like Hypertrophy Specific Training) may be better.

On my forum I have a generic bulking routine, upper/lower split with each hit 2X/week that has worked well for some. Bryan Haycock's Hypertrophy Specific Training (HST) has worked extremely well for many people, it has trainees hitting each bodypart 3X/week. Finally there is DoggCrapp training (do a Yahoo search, he doesn't have a site) which hits everything hard once every 5th day, it has generated size gains in a tremendous amount of people.

Training each bodypart 1X/week just doesn't seem to work the best for natural lifters.

Also, not everyone responds well to CKD's. You may want to try a moderate carb diet instead, both for gaining and dieting

Q: Are there any advantages to lifting heavy 2-3 times a week, while training for a marathon?

A: I think so, yes although I'd set a limit on lifting to twice per week, full body. This could be a very basic routine, something like a leg exercise (squat or leg press), pushing exercise (flat or incline bench or shoulder press), a pulling exercise (rows, pulldowns) and some tinkering (core, calf work). Warmups to a handful (1-2) sets of 6-8 repetitions would be about right and will maintain strength quite nicely without cutting too far into your recovery. IF you wanted to follow that up with a single high repetition set (20-25 reps done fairly slowly) to improve local muscular endurance, that might not hurt. This shouldn't take more than about 30-40 minutes in the weight room.

There is some research suggesting that heavy strength training can improve endurance performance, especially for less than elite performers. I think weight training is also useful for injury prevention.

One big issue is that of how to sequence the weight training in with you're running. I'd recommend doing the weights on a running day (after running of course) preferably before a day off. You wouldn't want to lift on, say, the night before your long run. You might lift something like Tue/Fri or Tue/Saturday and try to make Wed and Sun days completely off. Any equivalent spacing of the workouts would work fine.

I think that lifting 3X/week during marathon training would be overkill and would detract from your running training.

Q: Question do you still believe in the ketogenic ratio for getting into ketosis?I am having trouble showing ketones any tips? Sorry to bother you again but can drinking 2 gal of water per day dilute your urine so you don't show ketones?

Ok, one at a time.

In my first book, I talked about something called the ketogenic ratio (KR) which is an equation/concept used in the planning of ketogenic diets for epilepsy patients. The equation basically gives you the potential ketone producing potential of a given meal depending on the relative ketogenic or anti-ketogenic effect of protein (partially ketogenic, partially anti-ketogenic), carbohydrate (100% anti-ketogenic) and fat (mostly ketogenic) in a given meal. For epilepsy patients, this appears to be crucial to the success of the diet since high levels of ketones seem to be very important to controlled epilepsy.

However, invariably when people tried to apply the KR to fat loss diets, one of two things happened: either protein intake ended up being too low, or fat intake (and hence caloric intake) ended up being too high. Neither was optimal from either a fat loss or protein sparing standpoint.

Additionally, there isn't convincing evidence that ketosis is that crucial for the benefits of the diet, assuming protein intake is sufficient in the first place. This is especially true if protein is adequate (meaning 1-1.5 g/lb lean body mass) in the first place. Yes, ketones may (or may not) blunt appetite but even this is inconsistent and debatable at this point.

I don't think the KR or even ketosis is that important to the success (or failure for that matter) of a low-carbohydrate diet. In my Ultimate Diet 2.0 I made this very explicit in a section called "What about ketosis."

Which brings me to the second set of questions. For background, note that low-carb dieters have often used a product called Ketostix which change color to indicate the concentration of ketones in the urine. The problem is that urinary ketones are, at best, an indirect indicator of the concentrations of ketones in the bloodstream (which is the true definition of whether or not you're in ketosis). No, you can't put a drop of blood on the Ketostix (I tried). Now, if there are ketones in your urine, you certainly have them in your bloodstream. But the absence of ketones in your urine doesn't mean that you're not in ketosis (which, as above, doesn't really matter anyhow) because a variety of things can influence whether or not ketones are present in sufficient quantities in the urine to change the sticks colors. You might not be making enough ketones to excrete a lot of them (this happens in lean people, especially if they are very active), lots of water can dilute your urine and the ketone concentration, some other variables can impact on whether or not you show ketones on the ketostix.

At the end of the day, I don't think focusing on ketosis (or the lack thereof) is worthwhile: you can show plenty of ketones by gorging on dietary fat (especially MCT) but you won't be losing fat that way. And you can lose plenty of fat and never show a single ketone. I have seen too many dieters focusing on the Ketostix instead of what's important: relative amounts of fat and lean body mass lost. Focus on the latter, if you're losing fat and maintaining LBM, your diet (low-carbohydrate or otherwise) is working, whether you are in ketosis or not.