Measuring upper body strength is common in high school, college and professional level sports. Arguments have been made for and against this practice, but that’s for another day. The prime movers in the bench press are the pectoralis major, triceps brachii, anterior deltoid and medial deltoid. However the medial deltoid acts more like a stabilizer than a prime mover. Just for the record, the deltoid is one muscle; Anterior, medial and posterior simply describe areas, they aren’t separate heads.

Two of many ways one can perform a bench press is with a free weight barbell or a smith machine. The free weight bench forces the lifter to balance while exerting force to lift the weight. This higher level of instability is essential for a lifter who wants to engage the stabilizing muscles while training. A smith machine guides the bar in a fixed path and requires almost no balance by the lifter. The almost total lack of instability is thought by many to allow for increased force production of the prime movers. If this were true, bodybuilders or powerlifters who want to concentrate on the development of the prime movers, would be able to accomplish this with the smith machine. More-over, a lifter involved in rehab, novice lifters and elderly lifters may find the smith machine fits there needs because of the lack of instability.

A study published in the Journal of Strength and Conditioning Research compared the muscle activation between the free weight bench and the smith machine. The purpose of the study was to compare the muscle activation of the pectoralis major, anterior deltoid and medial deltoid during both exercises.

14 experienced and 12 inexperienced subjects were used in the study. Testing took place in two visits one week apart from each other, each consisting of either smith machine or free weight benching. Electromyography was used during the concentric phase of each lift at a lower intensity (2 reps at 70% of 1 rep max) and higher intensity (2 reps at 90% of 1 rep max) to compare muscle activation.

The study found no difference in the activation of the pectoralis major and the anterior deltoid between exercises regardless of load or experience. If the lack of instability of the smith machine allows the lifter to create more force production in the prime movers compared to the free weight bench press, it was not supported in this study. The authors surmise this may be due to the unnatural bar path of the smith machine in contrast to the free weight bench. Also, activation of the medial deltoid was significantly greater during the free weight bench regardless of load and experience. The instability of the free weight bench causes a greater activation of the medial deltoid as a force producer and stabilizer.

(J Strength Cond Res 24(3): 779-784,2010)

From a practical standpoint, according to the findings of this study, the free weight bench press may lead to a greater requirement of stabilization of the glenohumeral joint (shoulder). Increased shoulder stabilization is not only important for athletes but anyone involved in weight training, which requires strength and stability about the glenohumeral joint.

Do the findings of this study suggest dropping the smith machine from your training program and concentrating on free weight bench pressing? Absolutely not. The best thing one can do in regards to exercise choice, is mix things up. There are many exercises one can use in order to build their chest and shoulders. Don’t get caught in a rut using the same exercise over and over.

there are many biological factors that are important for muscular hypertrophy like hormone levels, age, sex, muscle fiber type, diet, among others. These factors have been recognized as extremely important for the hypertrophic adaption to strength training. Many of these factors, however, are known to vary throughout the day. Can the daily differences in the above factors like hormone levels, affect the adaptive response to strength training? What time of day is the best time to train?

A study published in the Journal of Strength and Conditioning Research set out to examine the effects of time-of-day-specific strength training on muscle hypertrophy maximal strength in men. The training group underwent a 10 week preparatory training regimen. Afterwards, the subjects were randomized to either a morning training group or an afternoon training group. The groups trained for another 10 weeks with training times between 07:00 and 09:00 hours and 17:00 and 19:00 hours in the morning group and the afternoon group respectively. Cross-sectional areas and volume of the quadriceps femoris were obtained by magnetic resonance imaging at weeks 0, 10, and 20. Maximum voluntary isometric strength during unilateral knee extensions and the half squat one repetition maximum were tested at weeks 0, 10, and 20.

The entire 20-week training period resulted in significant increases in maximum voluntary contraction and 1RM in both training groups. In this study, the magnitude of muscular hypertrophy and strength did not statistically differ between the morning or afternoon group. However, this study was of short duration and like most research concerning physical improvement through exercise, there needs to be more subjects over longer periods of time.
(J Strength Cond Res 23(9):2451-2457)

Exercise induced endogenous hormone levels have been studied extensively. Researchers have examined how the different components of training including sets, repetitions, load and rest intervals affect serum levels of hormones such as testosterone, growth hormone and cortisol. Many studies have demonstrated there is an acute increase in serum levels of anabolic hormones after intense resistance exercise.

To be more specific, high intensity exercise coupled with short rest intervals that is performed with large muscle groups are associated with large rises in these hormones when compared to other training methods. Conversely, training small muscle groups like the biceps has been shown to have no effect on serum hormone levels. Because of the findings in many studies, training programs have been constructed to maximize the post-exercise rise in these hormones based on the assertion that exercise-induced increases in hormones like testosterone and GH will enhance muscle size and strength. But, considering the fact that these increases in hormone levels are very small and of short duration, will they produce muscular gains.

A study from the Kinesiology Dept. of McMaster University in Canada found that exercise induced hormone levels had no effect on muscle size or strength after 15 weeks of resistance training.

There is evidence that a minimal basal level of testosterone is required to support strength and hypertrophy gains, which are otherwise attenuated. Therefore, the hormone-sensitive processes that underpin muscle anabolism at hypo- and supra-physiological hormone levels are not being activated appreciably by exercise-induced increases in hormone availability or at least do not result in any measurable enhancement of strength or hypertrophy.

(J Appl Physiol 108(1); 2010)

Many strength and muscle building experts will say, the barbell back squat is much more effective at building size and strength. They argue free weight squats are a more natural movement and require much more stabilization and balance, which increases its effectiveness. However, the Smith machine is much easier to learn, especially for beginners, which many argue is safer. I contend that it depends upon the person’s build. If one has long legs and a shorter torso, they will have a very difficult time performing a squat correctly in order to get optimum stimulation for strength or growth. In this case and in others, they would benefit greatly from performing smith machine squats. But what does science have to say? Which is better for gaining strength?

Researchers from the University of Saskatchewan in Canada compared the free weight squat to the Smith machine using electromyography (EMG). The purpose of their study was to determine which exercise was better at stimulating the prime movers and stabilizers of the legs (e.g., tibialis anterior, gastrocnemius, vastus medialis, vastus lateralis and biceps femoris) and trunk (e.g., lumbar erector spinae and rectus abdominus). Six healthy participants performed 1 set of 8 repetitions using a weight they could lift 8 times, i.e., 8 rep maximum.

Contrary to our hypotheses, muscles of the legs (specifically the vastus medialis and biceps femoris) displayed greater EMG activity during the free weight squat compared to the Smith machine squat, whereas there were no differences between exercises for EMG activity of trunk stabilizers.

Researchers conclude that the free weight squat may be superior to the Smith machine squat for training the major muscle groups of the legs and possibly would result in greater strength development and hypertrophy of these muscle groups with long-term training.
Journal of Strength and Conditioning Research, 23(9), 2588-2591.

Some say the squat is the king of all leg exercises. They even go as far as saying that if you don?t squat, your chances of building big, strong legs are next to impossible. And there are others who even take it one step further, claiming the squat is the best overall exercise there is period, and no routine should be without one.

Yes, I agree that the squat is unquestionably a very productive exercise in that it works a large number of major muscle groups. More so than any other exercise, however, it is not essential to do the barbell squat in order to get muscular and strong legs. More-over, for some the pain caused by injuries or anatomy makes this exercise very uncomfortable and unproductive. For instance, those who have very long legs and short torsos have trouble doing squats due to bad bio-mechanics. Some people need alternatives, but, for this Exercise of the Month article I focus on how to perform the barbell squat properly and show how to change what muscles are emphasized.