Note: This is part two, click here for part one.
I am fortunate that as part of my job as a scientist, I get to travel all around the country presenting research and listening to colleagues from around the world discuss theirs. This week I'm going to bring to you some of the work I heard recently at a conference I attended.
Thermogenics are always popular. Dr. Arciero presented the results of his groups study comparing green tea, caffeine, and ephedrine combinations on resting energy expenditure, fat oxidation, heart rate and blood pressure. They compared the effectiveness of 200mg caffeine, 270mg of catechin polyphenols from green tea extract, caffeine-green tea (200mg and 270mg, respectively), and caffeine-ephedrine (40mg and 12mg, respectively).
In this small study with 10 subjects, the researchers found that the caffeine-only group had a small, but significant increase in thermogenesis whereas none of the other groups showed any significant favorable effect on thermogenesis or any of the other outcome parameters.
Xenadrine RFA-1was the next product under the microscope, as researchers from Adelphi University compared this popular thermogenic to caffeine and plain ol' food by measuring resting metabolic rate (RMR.
In this double-blind, crossover study, researchers tested each of the nine subjects by giving them food only, food plus Xenadrine RFA-1 (670 mg ephedrine), or food plus caffeine (600mg caffeine) and measuring RMR. Their results demonstrate that there were no significant benefits to any of the purported thermogenic agents, when given in the recommended dosage.
From this study, it looks like the thermic effect of food is comparable to two popular products used to increase RMR and therefore, lose body fat. This study is in contrast to the previous one which showed a significant increase in thermogenesis from consuming the caffeine alone; potentially, the food in this study may have inhibited the uptake and absorption of the caffeine, therefore decreasing its full thermogenic properties, but that is just speculation.
Dr. Vukovich presented another study comparing the effects of caffeine and ephedrine on resting heart rate, blood pressure, and energy expenditure in eight healthy males. Subjects consumed either a placebo or 150 mg of caffeine and 20 mg of ephedrine, after a 12 hour food fast and 48 hour caffeine fast.
Participants were moderate caffeine users (150 to 300 mg/day), therefore reducing the confounding factor of introducing a "foreign" substance to their bodies. Following supplementation, heart rate, blood pressure, and energy expenditure were significantly higher than that of the placebo group.
Anectodally, users swear by these products; however, one cannot negate these important findings - elevated heart rate and blood pressure, compounded with the same effect from intense exercise, could potentially result in negative side effects.
Contrary to the anecdotal information many of us hear on a daily basis, here's some legit evidence demonstrating that interval training may be more beneficial than steady state training, if your goal is overall weight and fat loss. Researchers divided 15 obese female subjects into either a steady-state group or an interval training group.
| Implementing various compound lifts (those that utilize more than one muscle) are excellent for burning body fat and adding lean muscle.
These exercises burn more calories and stimulate specific hormones that may be beneficial in body composition changes. In essence, they provide the "biggest bang for the buck" in training.
Both groups were monitored so they had the same mean intensity, duration, and caloric expenditure (300 kcals) during each workout.
This group found that interval training, independent of workload, significantly improved caloric expenditure at a given RER value and, therefore, absolute fat utilization as well.
To reiterate the point from my last article and what's been said on this site for years, sprinting instead of jogging at a steady pace is ideal for optimal fat loss and total caloric expenditure.
They used 55 untrained male and female subjects and randomized them into one of three training protocols: group 1 performed one set of eight exercises, group 2 performed three sets of the same eight exercises, and the third group performed one set of 24 exercises (intended to introduce variety, as well as high volume).
All exercises were performed for 8-12 RM and the training protocols lasted for 24 weeks. Not surprisingly, each group improved in each of the parameters assessed (remember they were untrained). Aside from a potential advantage in the multiple set group in bench press strength, the researchers concluded that there were no clear advantages over one program to another in previously untrained subjects.
Ever wonder how maximal power and force are affected over the course of a competitive collegiate football game? Me neither. But this study, or those of similar ilk, may effect an athletes overall performance so from that standpoint it peaked my interest.
The purpose was to examine the changes in force power production in the leg extensors over four quarters of a collegiate football game. The subjects were either players or non-players, but all were part of the team and participated in the various aspects of the team activities (aside from the game itself, in the case of the non-players).
Subjects were tested for jump performance (via the squat jump and countermovement jump) immediately prior to the game and at the completion of each quarter. The results showed that there was a significantly higher force and power output in players, compared to non-players.
The initial warm-up period is obviously transient, as the increases in force and power did not carry over in the non-players, as they did with the players who were active the entire game. What this means for you and I, is hop under the squat rack cold and you will probably be limited in the amount of iron you can push.
Scientists from Australia presented their work comparing a whey isolate vs. casein through resistance training on strength, body comp, and plasma glutamine.
Thirteen subjects were given either 100% whey isolate or casein protein (1.5 gm/kg body weight/day) and were simultaneously under the careful eye of researchers, who supervised each workout three days/week.
Interestingly, this group found that the 100% whey isolate was more effective at increasing muscle mass (~ 5 kg over 10 weeks) vs. the casein group who gained < 1 kg over the same time period. The whey group was also more effective at increasing strength and decreasing fat mass compared to the casein group.
Both proteins seemed to prevent the typical decrease in plasma glutamine levels that are common with exercise. With the simple addition of protein, these results surprise me; however, it is what it is and all research should be taken with a grain of salt.
In a study out of Shriners Hospital in Texas, researchers assessed the affects of essential amino acids (AA) and muscle protein recovery from resistance training exercise. This same group has published their data demonstrating the benefits of 6 gm of AA in addition to 35 gm of sucrose on muscle protein synthesis; however, the effect of AA alone remains elusive.
Subjects performed a resistance training bout consisting of 10 sets of 10 reps of leg press and 8 sets of 8 reps of leg extension (not sure how they came up with this particular protocol, but that's why it's their study and not mine). Each subject then received 0.087 gm of essential AA/kg body weight. They learned that this supplement stimulated muscle protein synthesis following exercise and arterial EAA concentrations increased several-fold following drink consumption (16).
In my humble opinion, it would be interesting to compare the EAA head to head with another group who consumes the same amount of EAA, along with 35 gm of sucrose.
I hope you found these research studies to be as useful and exciting as I did. Each time I attend a conference, you can be sure to find the summary of the more pertinent findings right here on this very website.
Note: This is part two, click here for part one.