American Journal of Physiology-Endocrinology & Metabolism - 284, E76-E89, 2003
Acute response of net muscle protein balance reflects 24-h balance after exercise and amino acid ingestion
Kevin D. Tipton, Elisabet Borsheim, Steven E. Wolf, Arthur P. Sanford and Robert E. Wolfe
This team of researchers is well-known for their work with protein and amino acids. The intended outcome of this investigation was to determine if the acute combined anabolic effects of resistance exercise and essential amino acids (EAA) reflect the response over 24-hours.
Seven subjects underwent two 24-hour studies: 1) rest and 2) rest plus resistance exercise (eight sets of eight reps of knee extensions at 80% 1RM) and consumption of EAA (15 g pre-exercise and 15 g 1 hour post-exercise).
During the EAA supplementation protocol, amino acid concentrations were increased about 3.5-4 times and remained elevated for ~ 4 hours. Moreover, nitrogen balance was also elevated immediately following exercise with EAA supplementation.
Data from this study support the theory that bodybuilders have known (or at least practiced) for years; supplementation with amino acids (of course combined with resistance training) improves net muscle protein balance. Until more research is completed, I would recommend sticking with a quality pre- and post-workout drink, comprised of whey protein and some carbohydrates, as opposed to supplementing solely with amino acids.
Medicine & Science in Sports & Exercise, Volume 34, Number 11, 2002
Caffeine is ergogenic after supplementation of oral creatine monohydrate
Mike Doherty, Paul M. Smith, R. C. Richard Davidson, and Michael G. Hughes
Caffeine may elicit ergogenic benefits. Although a majority of the studies have tested caffeine's effects in endurance performance, some research protocols have also measured caffeine's effects on short-term high-intensity exercise. The purpose of this current study was to determine if supplementation with creatine monohydrate would negate the known ergogenic effects of caffeine, as one previous study had demonstrated.
Fourteen male subjects were tested on four different occasions. A preliminary test was first utilized to obtain a VO2 max (maximal oxygen uptake). Next, during the pretreatment period, all subjects were provided with creatine and underwent a loading regimen for 6-days (0.3 g/kg bodyweight taken at 4 regular intervals throughout the day) and completed a test at a running speed of 125% of their previously measured VO2 max.
Next, 12-24 hours after the completion of the creatine loading phase, subjects were provided with caffeine (5mg/kg) or placebo and completed the same abovementioned VO2 max test. The moral of the story is that this study demonstrated that acute ingestion of caffeine still has ergogenic benefits for short-term exercise regardless of previous creatine ingestion.
Journal of Strength and Conditioning Research, 16(4), 530-538, 2002
The Acute Effects of Heavy Loads on Jump Squat Performance: An Evaluation of the Complex and Contrast Methods of Power Development Grant M. Duthie, Warren B. Young, and David A. Aitken
The purpose of this study was to measure power performance in jump squats when using either complex or contrast training methods. The group of 11 women were involved in three randomly assigned training sessions consisting of 3 sets of both of the exercises mentioned below:
- jump squats before half squats (defined in this study as squatting until the thighs are parallel with the ground) or "traditional method"
- half squats before jump squats or, "complex method"
- alternating sets of half squats and jump squats or, "contrast method".
In this particular study, the half squat was used as the heavy load exercise and the jump squats were used as the lighter load exercise, as these were both exercise the subjects were accustomed to.
Let's cut to the chase. The investigators found that higher level strength athletes may benefit from the contrast training method (alternating heavy load and light load exercises), as the stronger athletes in this study (females with a 1RM squat > 135 kg) benefited most from this method of training.
Moreover, the complex method of training (heavy load prior to light load) resulted in a significant decrease in performance during the first set of the second exercise, which the authors concluded may impair power development overtime.
Medicine & Science in Sports & Exercise, Volume 34, Number 11, 1793-1800, 2002
Resistance and aerobic exercise have similar effects on 24-h nutrient oxidation
Edward L. Melanson, Teresa A. Sharp, Helen M. Seagle, William T. Donahoo, Gary K. Grunwald, John C. Peters, Jere T. Hamilton and James O. Hill
The primary aim of this study was to compare the effects of aerobic vs. anaerobic training on energy expenditure (EE) and substrate oxidation. It has been discussed ad nauseam whether cardiovascular exercise or weight lifting is better for weight loss; however, much of the discussions have been based on anecdotal evidence rather than actual research. In fact, just the other day I overheard an enlightening conversation between a "certified" personal trainer and his overweight client regarding the importance of completing high rep sets of leg lifts to "tone" the muscles of the legs. I digress.
This study tested 10 non-obese male subjects on four separate occasions using whole-room, indirect calorimetry. The first measurement was utilized to obtain a baseline EE. Next, in random order, 3 more EE measurements were completed over a 4-week period:
- an aerobic-exercise test (stationary bike at 70% VO2 max)
- resistance-exercise (4 sets of 10 different exercises at 70% of exercise-specific 1 RM)
- a non-exercise control day
During the bike session, subjects exercised for 49 ± 2 minutes and expended 546 ± 16 kcal. The 60-minute circuit training lifting regimen resulted in a 448 ± 21 kcal EE. Both exercise regimens had similar effects on substrate oxidation (there were no differences in fat oxidation over 24 hours, but there was an increase in the amount of carbohydrates oxidized).
Looking at the results from this study alone, we can infer that if the primary goal with an exercise program is weight loss (with no regard to the composition of that loss) there is a greater EE during aerobic exercise than a circuit type anaerobic exercise program.
So what have we learned today in the first installment of Research Roundup?
- EAA supplementation pre- and post-training enhances protein synthesis.
- Using the abovementioned contrast training method may enhance power development overtime in stronger athletes (although variety in your training program does wonders too).
- Leg lifts are important for toning our inner thighs.
- Aerobic exercise will utilize more energy in a shorter amount of time than a circuit-training anaerobic regimen.