A: Use of exercise balls for abdominal work, as well as other types of exercise, has grown tremendously over the last several years. Consequently, sport science research is starting to examine their efficacy. A recent project by Canadian researchers examining muscle use during several abdominal exercises indicates a curl-up on an exercise ball is quite an effective strength training exercise. The researchers examined upper and lower rectus abdominis use during six different ab exercises. They utilized electromyographic (EMG) techniques to look at upper (above the navel) and lower (below the navel) rectus abdominis use.
The six exercises included the normal curl-up, exercise ball curl-up, curl-up using an abdominal trainer (Ab trainer), leg lowering while lying flat on your back, exercise ball rollout and the reverse curl-up. While you're probably familiar with most of these exercises, you may not be familiar with the last two. The exercise ball rollout is performed kneeling on the floor with your forearms placed on the exercise ball. You roll the ball forward until you're in a fully extended position with your hips extended and your upper arms almost parallel to the floor. You then roll the ball back to the starting position. The reverse curl-up is performed lying flat on your back with your hips at a 90-degree angle and your legs extended toward the ceiling. You curl your hips toward your ribs, then allow your hips to return to the starting position where they are in contact with the floor.
All the exercises resulted in significant upper and lower rectus abdominis use. None showed a significant difference between use of the upper and lower rectus abdominis. The exercise ball curl-up resulted in significantly greater upper and lower abdominis use compared to all the other exercises. Additionally, the normal curl-up, exercise ball curl-up and abdominal trainer curl up showed significantly greater upper and lower abdominis activity than the reverse curl-up, the leg lowering exercise and the exercise ball rollout. Because all the exercises did elicit significant upper and lower abdominis use, they can all be used to successfully train your rectus abdominis. The results also indicate that the exercise ball curl-up is at least as effective, and in some cases even more effective, than several other common ab exercises. (J Strength Cond Res, 17:475-483, 2003)
Q: I used to do cycling or running for my cardiovascular training. Recently, I started to do the BODYPUMP workout instead. Will BODYPUMP training be enough cardio for me?
A: The BODYPUMP workout has become very popular for cardio training. Your question concerns the intensity of the workout and the number of calories metabolized during a typical session. New Zealand researchers recently published an article comparing a typical BODYPUMP training session to a cycling cardiovascular training session. They measured heart rate, oxygen consumption, calories burned and percent of calories burned from carbohydrates and fats.
People experienced at performing a BODYPUMP training session had an average heart rate of 135 beats per minute and burned an average of 411 calories during the BODYPUMP session. Additionally, approximately 17 percent of the calories burned came from fat and 83 percent came from carbohydrates. Oxygen consumption during the BODYPUMP session averaged 41 percent of the subjects' peak oxygen consumption. It's important to note that the typical minimal training intensity guideline to bring about cardiovascular fitness changes is 50 percent of peak oxygen consumption.
During an hour long cycling training session, the subjects burned on average 623 calories of which 27 percent came from fat and 73 came from carbohydrates. The authors concluded that a typical BODYPUMP session provides a low to moderate stimulus to improve aerobic fitness and that it should not be used as the only method of cardiovascular conditioning. They also concluded that a BODYPUMP session does result in significant caloric expenditure and probably provides other fitness benefits, such as local muscular endurance increases and maintenance of a healthy body composition. However, the cycling session did result in a greater caloric expenditure and a higher percent of calories burned coming from fat metabolism. So BODYPUMP training can be used as part of your cardiovascular training program, but you may want to consider alternating BODYPUMP training with other types of cardio training, such as cycling, running and rowing. (Fitn & Perf J, 2:113-121, 2003)
Q: I recently read an article about agonist-antagonist superset training. What do you think about this type of training?
A: During typical agonist-antagonist superset training, agonist and antagonist muscles are trained back to back with little or no rest between sets. Some lifters use this type of training extensively and claim it's of tremendous value to their total training program. Unfortunately, there's little sport science information concerning this type of training. A recent study from Marquette University did, however, look at some aspects of it. Two muscle groups that are sometimes trained using agonist-antagonist superset training are the hamstrings and quadriceps. These are the two muscle groups examined in this study. Torque development, muscle activity using EMG techniques and rate of force development of the quadriceps were looked at when the hamstrings were pre-fatigued and not pre-fatigued.
The researchers used isokinetic (constant velocity of movement) techniques for this study. The hamstrings were pre-fatigued by performing five maximal knee flexions at velocities of 60, 180 and 300 degrees per second. This means if the knee joint moves through 90 degrees during knee flexion, it would take 1.5, 0.5 and 0.3 seconds to perform each repetition at 60, 180 and 330 degrees per second, respectively. Pre-fatiguing the hamstrings resulted in significant decreases of the quadriceps' peak torque of 1.7 percent, peak power of 11 percent, and rate of force development of 6.4 percent compared to the non-pre-fatigued values. It was also noted that the greatest decreases in peak torque, power and rate of force development occurred at 60 degrees per second- a velocity representative of typical movement speeds during weight training.
The authors concluded that their results indicate agonist-antagonist superset training may not be the most effective weight training system because of the reduction in force, power and rate of force development subsequent to pre-fatiguing an antagonist muscle. They also note that the performance of the quadriceps was most affected at a velocity (60 degrees per second) representative of typical weight training movement speeds. Alternatively, pre-fatiguing the hamstrings had little effect on quadriceps performance at higher movement speeds (180 degrees per second). This raises a question about whether pre-fatiguing an antagonist muscle group would have any positive or negative effect on power-type training such as plyometrics. The decrease in quadriceps performance after pre-fatiguing the hamstrings is probably related to the 25 percent greater amount of hamstring EMG activity found during quadriceps use after pre-fatiguing the hamstrings. This means the hamstrings were more active during quadriceps use after the hamstrings were pre-fatigued.
The greater activity of the hamstrings results in generation of force by the hamstrings during quadriceps action. Because the quadriceps extends the knee and the hamstring flexes the knee, the quadriceps would have to develop more force to overcome the additional force developed by the hamstrings. The net result of this would be lower measurable force and power development by the quadriceps. So, despite the popularity of agonist-antagonist superset training, it may not be the best training method for strength development. However, agonist-antagonist superseting definitely needs to be researched more before a definitive answer concerning its effectiveness can be reached.
(J Strength Cond Res, 17:469-474, 2003)
