Researchers have previously suspected and shown in animal studies that women incur less muscle damage than males after strenuous exercise. This may be due to a natural defense mechanism or estrogen levels. However there is virtually no data on humans. One study showed that both men and women exhibited similar muscle damage, soreness patterns and recovery rates.
Subjects: 165 (83 female - 82 male) = Larger Power for the study
Protocol: Isokinetic lever arm with the subjects seated in a preacher bench apparatus to simulate heavy preacher curl eccentrics to evoke maximum muscle damage on the biceps and brachialis muscles.
Adverse effects: Subjects couldn't straighten their arms for 3 days post intervention
(common in un-trained individuals!)
Outcomes: Muscle soreness, maximal force production and resting joint angle of the elbow were used to assess recovery every 24hours up to 168 hrs after the bout of exercise.
Results: Peak soreness occurred at 48 hours after exercise and strength levels were still down 168 hrs (7 days) after the test. Isometric contraction was used as an assessment of muscle damage, and does appear to be a more reliable indirect indicator than blood creatine kinase (CK) levels.
Conclusions: men and women recover at equal rates and women do not experience less muscle damage than men.
Ref: Response of males and females to high-force eccentric exercise. J.of Sports Sci.18:229-236,2000.
Low Carb? No good
Research out of Denmark has shown extreme diets may have a detrimental impact on immune function. They suggest that going too low in the carbohydrate department may reduce immunity.
Design: 20 untrained men on 1. (high carbohydrate (65%) low fat (20%)) or 2.(high fat (62%) low carb (17%)diet)
Training: Both groups same intensities and equal adaptations (VO2 max increases). All efforts were taken to keep protein levels constant (around 20%).
Outcomes: immunological tests were carried out before and after the varied intensity training program. Immune function was shown to be compromised in the higher fat/low carb group. Natural killer cell (NK Cells) function that is part of the natural immune response to invading organisms was reduced in the low carbohydrates/ high fat group.
Key points: No reference to the dietary origins of fat ingested were noted and this is important. Data on this aspect of nutrition and exercise performance is lacking. These results however do suggest if carbs are dropped too low for a prolonged time frame (in this case 7 weeks), some aspects of immune function do suffer. This may lead to an increased susceptibility to illness or infection.
Ref: Training and natural immunity: effects of diets rich in fat or carbohydrate. Euro Jour Appl Physiol. Pp.82:98-102, 2000.
As you may all know, I am very pro -carbs... woot.
