Fitness Research Review
Frederick C. Hatfield II, MS, MFS, CSCS
Rest Time Between 1RM Attempts
Researchers from The University of Memphis and Lambuth University recently studied the effects of several different rest periods between 1RM squat attempts. Seventeen weight trained men in their early twenties performed a baseline 1RM in the squat before engaging in three different sessions involving two 1RM squats. They were given either 1, 3 or 5 minutes rest between attempts. During the 1 minute resting test, 13 of 17 subjects were able to repeat the 1RM. For the 3 minute resting test, 16 of 17 were able to repeat the 1RM. For the 5 minute resting test 15 of 17 were able to repeat the 1RM. A Cochran Q analysis revealed no significant differences between the rest times. The researchers concluded that 1 minute rest is sufficient recovery between 1 RM attempts.
Left unexplained was whether the lifters used supersuits or wrapped their knees before each attempt. Both of these items are known to take a lot of energy to put in place prior to lifting. Also, the heavier lifters (especially in the super-heavyweight division) tend to become severely short of breath following a maximum lift. These questions would be important before one could place any confidence in these research findings for use at powerlifting competitions. Non-significant differences aside, and judging on the basis of my own personal experience as a powerlifter, I'd opt for at least 3 minutes of rest. This is usable research. Powerlifting meet directors may well be able to use this research to justify shortening meets so they don't last until the late evening hours!
The Journal of Strength and Conditioning Research: Vol. 17, No. 4, pp. 634-637.
Aerobics and Strength Training
This study comes to us from the University of Victoria in Canada. Researchers were looking to determine how much rest is needed between aerobic training and strength training performance. Sixteen male subjects performed 4 sets of bench presses and leg presses (75% of 1RM) following aerobic training with different amounts of recovery time between exercise sessions (4, 8 and 24 hours). It was found that the number of leg press repetitions decreased when rest time was between 4 and 8 hours, but not 24 hours. No changes were found between rest times in the bench press.
It would've been interesting to see a study placing strength training before aerobic training. However, this research indicates that aerobics before strength training is not a good idea, especially if you are using the same muscles for both forms of exercise.
The Journal of Strength and Conditioning Research: Vol. 17, No. 4, pp. 638-644.
Olympic Weightlifters, Sedentary Subjects and Muscle Fiber Typing
Several researchers from around the country recently looked at the differences of muscle fiber characteristics between weightlifters and non weightlifters. Let's look at the muscle fiber breakdown between the two groups:
| Subject |
Type IIC Percent |
Type IIA Percent |
Type IIB Percent |
| Weightlifters |
0.4 |
50.5 |
1.7 |
| Non-weight trained |
2.4 |
26.9 |
21.0 |
Other things were looked at including capillary density and mysosin heavy chain content. But let's look at the fiber breakdown. Of course, the missing percentage of muscle fibers is type I fibers. Long-time readers of www.drsquat.com as well as ISSA personal trainers should be able to interpret what has happened and why there is such a large difference (as well as a smaller difference) between the group's type IIB and IIC fibers. Dr. Squat has long called type IIB fibers "Couch Potato" fibers because you get them by doing "nothing". Furthermore, the theory of "fiber fusion" indicates that type IIC fibers come about by "fusion" of satellite cells and type IIB fibers. These data do NOT disagree, and in fact supports that notion! Weightlifters simply do not spend enough time resting to develop type IIB fibers - nor should they during heavy training. This notion is not "new" in that former studies have also noted this phenomenon.
In short, ISSA was ahead of this research project by 15 years!
Something for you Sled Draggers
Researchers in Australia studied the affects of sled towing on sprint kinematics. Twenty men were tested while dragging a sled with loads of either 12.6 or 32.2% of their bodyweight. It was found that stride length was significantly reduced by 10 and 24% respectively. Stride frequency also decreased while ground contact time, angle of trunk lean, and hip flexion increased. Generally, running form was significantly affected at these loads.
In respect to this, I have to hand it to former University of Tennessee strength and conditioning coach, Bruno Pauletto. If you read the article, "Notes from the Legends of the Game Conference", he predicted that loads above 10% of the athletes bodyweight would affect running form. It would've been interesting if researchers lowered the towing load to under 10%. Sled towing has many benefits, but in terms of speed development, "more" is not better!
The Journal of Strength and Conditioning Research: Vol. 17, No. 4, pp. 760-767.
Soccer Schedules and Power Output
Researchers recently noted differences in maximal power output immediately following a collegiate female soccer game and 24 hours afterwards. It was found that the ability to exert maximal power was maintained during the game, but decreased 24 hours later. The significance of this study is that it supports the notion that sufficient rest is required after a game.
Mirrors In Gyms Give Bad Reflections
A Recent study suggests that mirrors in fitness centers are giving women a negative body image. The study was conducted at McMaster University in Hamilton, Ontario. It studied 58 sedentary women, who averaged an age of 21. Two bouts of exercise were performed on an exercise bike for 20 minutes. One bout was in front of a mirror, the other without a mirror. Before and after each bout of exercise, the women were asked a series of questions regarding their mood. It is reported that when the women could watch themselves in the mirror during exercise, they felt worse about themselves.
The researchers did not study men, but one of them speculated that men would have the same reaction, although probably to a lesser extent because they "tend to be less self-critical than women." The study also suggests that this trend may not be seen in more experienced individuals.
Food Pyramid To Undergo Reconstruction
One of the hot topics in the fitness industry today is the Department of Agriculture is considering changing it's dietary recommendations in 2005. Reports suggest that several factors will be taken into consideration, including the rising number of overweight and inactive Americans (the original food pyramid took it into consideration that Americans were healthy, active and not overweight). Also under consideration are factors such as gender, age and activity levels.
An interesting note to this story is that some nutritionists are already fretting over this. According to a recent story, there may be up to 12 different categories and nutritionists are worried that the guidelines may be too difficult for the average consumer to understand.
Hormone Therapy May Help Treat Obesity
British researchers are claiming that they have identified a hormone, which is less prevalent in obese people as opposed to their slimmer peers. It is being suggested that the hormone, PYY3-36, controls hunger. Obese people have one-third less of the hormone, which causes their appetite to increase. It is being suggested that increasing the amounts of PYY3-36 may help control the appetites of obese people.
Study Suggests PNF Stretching Is Better Than Static Stretching
Researchers from The University of Texas at Austin and The University of Louisville compared static stretching to Proprioceptive Neuromuscular Facilitation (PNF) to static stretching. Forty student athletes performed PNF with and without a prior bout of exercise. When using PNF techniques on their hamstrings, flexibility was increased while no increase was seen after static stretching.
Caffeine/Ephedrine's Effects On Muscular Endurance
While Ephedrine continues to be scrutinized in public opinion, a recent study in Medicine & Science in Sports & Exercise suggests that it does indeed have a positive effect on muscular endurance.
Thirteen subjects ingested either caffeine, ephedrine, a combination of both or a placebo before engaging in circuit weight training. The training sessions consisted of three supersets of leg presses and bench presses (80% and 70% respectively of their 1RM done to failure) with two minutes rest in-between. The results showed that when Caffeine and ephedrine were consumed, as well as ephedrine alone was consumed, the mean number of repetitions completed was significantly greater. There was no difference in the C+E group and the E group, suggesting caffeine didn't play a role in the increase.
This effect, however, was only seen in the first superset, but the researchers still contend that ephedrine has a positive effect in muscular endurance. It seems to me if muscular endurance was really enhanced, it would've been seen in the latter supersets, not the first.
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