Cold Vs. Heat After Exercise-Is There a Clear Winner for Muscle Soreness.

Because of the differences in the exercise type, temperature, and timing of the use of cold and heat after exercise in different studies, there is no clear conclusion as to the efficacy of either modality on reducing delayed onset muscle soreness. One hundred subjects at similar fitness levels were examined. They accomplished leg squats for 15 minutes and heat and cold were applied after or 24 hours after exercise using ThermaCare heat or cold wraps. Measurements obtained were strength, the force to passively move the knee, analog visual pain scales, and blood myoglobin. Control subjects lost 24% strength after exercise. Subjects with heat or cold just after exercise only lost 4% strength (p < 0.01). For strength recovery, cold applied after 24 hours was better than heat at 24 hours. Heat or cold applied after exercise was significantly better to prevent elastic tissue damage (p < 0.01), whereas heat and cold immediately after exercise caused no loss in muscle myoglobin and heat or cold after 24 hours showed no less muscle damage from myoglobin than in control subjects. Myoglobin in the control and heat and cold 24-hour groups averaged 135.1% of the baseline data but averaged 106.1% of baseline in the immediate heat and cold groups. For reducing pain, control subjects showed a significant amount of pain the days after exercise. But cold immediately after exercise or 24 hours later was superior to heat in reducing pain. In conclusion, both cold and heat appear to be efficacious in reducing muscle damage after exercise.

Moist heat or dry heat for delayed onset muscle soreness.

BACKGROUND: Heat is commonly used in physical therapy following exercise induced delayed onset muscle soreness (DOMS). Most heat modalities used in a clinical setting for DOMS are only applied for 5 to 20 minutes. This minimal heat exposure causes little, if any, change in deep tissue temperature. For this reason, long duration dry chemical heat packs are used at home to slowly and safely warm tissue and reduce potential heat damage while reducing pain associated from DOMS. Clinically, it has been shown that moist heat penetrates deep tissue faster than dry heat. Therefore, in home use chemical moist heat may be more efficacious than dry heat to provide pain relief and reduce tissue damage following exercise DOMS. However, chemical moist heat only lasts for 2 hours compared to the 8 hours duration of chemical dry heat packs. The purpose of this study was to compare the beneficial effect of dry heat versus moist heat on 100 young subjects after exercise induce DOMS. METHODS: One hundred subjects exercised for 15 minutes accomplishing squats. Before and for 3 days after, strength, muscle soreness, tissue resistance, and the force to passively move the knee were recorded. Heat and moist heat were applied in different groups either immediately after exercise or 24 hours later. RESULTS: The research results of this study showed that immediate application of heat, either dry (8 hours application) or moist (2 hours application), had a similar preservation of quadriceps muscle strength and muscle activity. Results also revealed that the greatest pain reduction was shown after immediate application of moist heat. Never the less, immediate application of dry heat had a similar effect but to a lesser extent. CONCLUSION: It should be noted that moist heat had not only similar benefits of dry heat but in some cases enhanced benefits, and with only 25% of the time of application of the dry heat.

The effect of previous weight training and concurrent weight training on endurance for functional electrical stimulation cycle ergometry.

Forty-five paraplegic subjects participated in three series of experiments to examine the interrelationships between previous weight training, concurrent weight training and muscle strength and endurance during cycle ergometry elicited by functional electrical stimulation (FES). When subjects only underwent isokinetic weight training (series 1) three times per week on the quadriceps, hamstring and gluteus maximus groups for 12 weeks, strength increased linearly with time for all three muscle groups from an initial average of 17 N to 269 N at the end of training, a 15-fold increase. In the second series of experiments, different groups of subjects either underwent no strength training prior to cycle ergometry or underwent strength training of these same three muscle groups for 2 weeks, four weeks, or 6 weeks prior to cycle ergometry. Any strength training was effective in increasing endurance for cycle ergometry. However, the rate of increase in endurance during cycle ergometry with no prior strength training was only 5 min per week, whereas the rate of increase in cycle endurance during ergometry was 14.6, 25.0, and 33.3 min per week increase in endurance after strength training for 2.4 and 6 weeks, respectively. When weight training was accomplished during FES cycle ergometry (concurrently) in a third series of experiments, there was an additional increase in endurance during cycling if strength training was concurrently accomplished. With no weight training, endurance increased 23 min per week, whereas with concurrent weight training at three times per week, endurance increased during cycling by 41.6 min per week. The results of these experiments seem to show a clear advantage of weight training concurrently and before FES cycle ergometry. Results are given as mean (SD).

Toward the optimal waveform for electrical stimulation of human muscle.

Electrical stimulation of the quadriceps muscle was used to elicit 4-min isometric contractions at 10% of the maximal voluntary contraction (MVC) in four male and three female subjects. The effect of four waveforms, including Russian, interferential, sine, and square, on the mean stimulation current required to achieve the desired contraction force, subjective comfort, and physiological responses was studied. Interferential stimulation, even at full power, could not elicit a sustained contraction at 10% MVC. The contractions elicited by electrical stimulation utilizing the sine waveform required significantly less mean stimulation current to maintain the desired force of contraction with consistently lower verbal rating scale scores and greater increases in oxygen consumption than either the Russian or square waveform stimulations. Russian waveform stimulation produced a significantly greater rise in galvanic skin resistance than the sine or square waveform while the changes in respiratory quotient were similar between waveforms. The data support sine wave stimulation as working the best by producing the desired muscle tension with the least mean stimulation current and therefore, the least tissue trauma while providing the most subjective comfort.