BRAINSTEM INJURY FOLLOWING MAXIMAL WEIGHT LIFTING ATTEMPTS

Influence of the breathing pattern during resistance training on intraocular pressure

This study aimed to assess the effect of the breathing pattern during resistance training on intraocular pressure (IOP). Twenty physically active collegiate students (7 women and 13 men) performed sets of 10 repetitions against the 10-RM (repetition maximum) load during the back-squat and biceps-curl exercises following 3 different breathing patterns: (I) Valsalva: holding the breath during the entire repetition; (II) normal breathing: holding the breath and exhaling during the first and second phases of the repetition, respectively; and (III) modified breathing: inhaling and holding the breath during the first and second phases of the repetition, respectively. Rebound tonometry was used to measure IOP before exercise, after each of the 10 repetitions, and after 1 min of recovery. The breathing pattern significantly affected the changes in IOP values (p < 0.001, [Formula: see text] = 0.509) with the normal breathing pattern providing lower increases in IOP values compared to the Valsalva (p < 0.001, d = 1.47) and modified breathing (p < 0.001, d = 0.96). Higher IOP values were observed for the back-squat compared to the biceps-curl exercise (p = 0.003, [Formula: see text] = 0.384). A normal breathing pattern should be recommended to avoid abrupt increments in IOP during resistance training. These findings may be especially important for individuals at high risk for glaucoma onset or progression due to the necessity of maintaining stable IOP levels to avoid the progression of this disease. In future studies, the inclusion of glaucoma patients would allow to assess the generalizability of these findings.

The Valsalva maneuver: its effect on intra-abdominal pressure and safety issues during resistance exercise

During resistance exercise, a brief Valsalva maneuver (VM) is unavoidable when lifting heavy loads (>80% of maximal voluntary contraction) or when lifting lighter loads to failure. It has been proposed that the performance of the VM during resistance exercise increases the stability of the spine because of augmented intra-abdominal pressure (IAP). However, resistance trainers are often advised to avoid the VM during resistance exercise because of potential adverse vascular events. The aim of this review was to establish the effect of the VM on IAP and to evaluate if the VM during resistance exercise is a safe practice. Relevant databases were searched to examine the effect of the VM on: (a) IAP and (b) hemodynamics during resistance exercise and reported adverse events. The data show that the VM alone increases IAP and that the VM augment IAP during various resistance exercises. An incremental rise in IAP was observed as the lifting intensity and effort increased, with IAP tending to be lower compared with peak IAP from the VM alone. The VM was associated with an increase in blood pressure during resistance exercise, but the VM alone was associated with greater hemodynamic changes. In conclusion, the VM effectively increases IAP, which may assist with spine stability and trunk rigidity during resistance exercise. The health risks associated with the VM during resistance exercise remain unconfirmed.

The power athlete

A number of normal daily and athletic activities require isometric or static exercise. Sports such as weight lifting and other high-resistance activities are used by power athletes to gain strength and skeletal muscle bulk. Static exercise, the predominant activity used in power training, significantly increases blood pressure, heart rate, myocardial contractility, and cardiac output. These changes occur in response to central neural irradiation, called central command, as well as a reflex originating from statically contracting muscle. Studies have demonstrated that blood pressure appears to be the regulated variable, presumably because the increased pressure provides blood flow into muscles whose arterial inflow is reduced as a result of increases in intramuscular pressure created by contraction. Thus, static exercise is characterized by a pressure load on the heart and can be differentiated from the hemodynamic response to dynamic (isotonic) exercise, which involves a volume load to the heart. Physical training with static exercise (i.e., power training) leads to concentric cardiac (particularly left ventricular) hypertrophy, whereas training with dynamic exercise leads to eccentric hypertrophy. The magnitude of cardiac hypertrophy is much less in athletes training with static than dynamic exercise. Neither systolic nor diastolic function is altered by the hypertrophic process associated with static exercise training. Many of the energy requirements for static exercise, particularly during more severe levels of exercise, are met by anaerobic glycolysis because the contracting muscle becomes comes deprived of blood flow. Power athletes, training with repetitive static exercise, derive little benefit from an increase in oxygen transport capacity, so that maximal oxygen consumption is increased only minimally or not at all. Peripheral cardiovascular adaptations also can occur in response to training with static exercise. Although the studies are controversial, these adaptations include modest decreases in resting blood pressure, reduced increases in blood pressure and sympathetic nerve activity during a given workload, enhanced baroreflex function, increases in muscle capillary-to-fiber ratio, possible improvements in lipid and lipoprotein profiles, and increases in glucose and insulin responsiveness. Some of these adaptations can occur in cardiac or hypertensive patients with no concomitant cardiovascular complications. In both healthy individuals and those with cardiovascular disease, the manner in which resistance training is performed may dictate the extent to which these adjustments take place. Specifically, training that involves frequent repetitions of moderate weight (and hence contains dynamic components) seems to produce the most beneficial results.

Can pressure overload cause sliding hiatal hernia? A case report and review of the literature

We describe a hiatal hernia of moderate size in a 31-year-old competitive bodybuilder to raise the question of whether such hernias are more likely in young elite resistance-trained athletes as a consequence of attempts to increase intra-abdominal pressure and thus decrease the strain on the lumbar spine.

Influence of breathing technique on arterial blood pressure during heavy weight lifting

Arterial hypertension occurring during heavy resistance exercise may be a risk factor for stroke in healthy young adults. Any training method that ameliorates the pressor effect of exercise should reduce the risk of stroke. The objective of this study was to observe the influence of breathing technique on arterial blood pressure (BP) generated during heavy, dynamic weight lifting. BP was recorded in 10 male athletes by radial artery catheterization. Each subject then performed double-leg press sets at 85% and 100% of maximum. Each exercise was performed twice, once with closed glottis Valsalva, and then with slow exhalation during concentric contraction. The mean BP at 100% maximum with Valsalva was 311/284. The highest pressure recorded in an individual was 370/360. With slow exhalation, the mean BP was 198/175 when the same 100% maximum was lifted (p < .005). A reduced pressor response was also noted at 85% maximal lifting with slow exhalation. Arterial hypertension produced during heavy weight lifting with Valsalva is extreme and may be dramatically reduced when the exercise is performed with an open glottis (without Valsalva). It is concluded that heavy resistance exercise is safer when performed while the subject breathes with an open glottis.

Exertional Headache

In brief Exertional headaches can occur brief dynamic efforts such as running and swimming. They can also stem from static exertion such as weight lifting. Described here are two patients who experienced headaches of sudden onset while waterskiing. The headaches recurred with other forms of exertion. Both patients had normal neurologic examinations and CT scans. After avoiding aggravating activities and taking nonsteroidal anti-Inflammatory medication as necessary, the patients' headaches gradually resolved.

Strength training in children and adolescents

Strength is the ability to exert muscular force against resistance. It is a fundamental requirement of most daily physical activities of children and of adults. Strength training is the use of progressive resistance exercise methods specifically to increase strength. Strength training for children and adolescents is not without risk. Proven medical concerns relate to back, shoulder, and other joint injuries and to hypertension and related diseases. However, the rate of injury is probably rather low, comparable to many youthful activities that are considered safe. Also, the incidence and severity of injury can probably be minimized by adherence to the guidelines presented. Children may be expected to become stronger with appropriate training. Increased strength can enhance their performance in those athletic activities in which strength, power, or speed are required. It may reduce the incidence and severity of overuse injury in sport. However, it cannot reasonably be expected to protect against serious, acute injury in sport.

Ascending aortic dissection in weight lifters with cystic medial degeneration

We report 4 cases of ascending aortic dissection in patients with long histories of weight lifting. In 2 of the patients, the initial symptoms of dissection developed while they were lifting weights. Two patients had a history of hypertension and 2 had previously used anabolic steroids. All 4 were successfully treated surgically. Histopathology showed aortic medial changes in all 4. We believe that the hemodynamic stresses of weight lifting, namely, a rapid increase in systemic arterial blood pressure without a decrease in total peripheral vascular resistance, in combination with aortic medial degeneration may have contributed to the development of the aortic dissection.