PT on the Net Research

Female Response to Exercise and Supplementation


This article is dedicated to women. There is an abundance of resistance training research using athletic male subjects, yet much less exists using female athletes with respect to the effects of supplementation or exercise sequence on aerobic and strength performance. Do women experience the same ergogenic effects as men when using creatine supplementation? What is better to do first: aerobic activity or weight training? This article will address these questions and hope to teach us more about women… I mean during exercise.

STUDY 1

This five-week study focused on the effects of creatine supplementation on body composition and 1RM strength in 16 female collegiate lacrosse players. Seven subjects consumed 20 grams/day for the first week and then two grams/day for the remaining four weeks, while the remaining nine subjects consumed a placebo.

The Results

The researchers found that the creatine group demonstrated significantly greater strength improvements than the placebo group (6.2 kg vs 2.8 kg); however, these increases were only found in the upper body (bench press) and not the lower body (leg extension). Interestingly, body composition did not change as measured by underwater weighing, yet did decrease when measured by skinfolds. No, health issues due to creatine supplementation were observed and all blood and urine samples were normal. These results suggest that creatine supplementation increases upper body strength, but does not appear to influence lower body strength and are unclear on its effect on body composition.

Andre’s Notes

You must be wondering why there were improvements in the upper body, but not in the lower body? Well, the authors suggested that trained athletes already have near-maximal storage of muscle creatine (due to their sport) and thus may have less potential for improvement. But, if this were true, then why did the upper body show improvements? It could just be that since the athletes’ sport involves a lot of the leg work, that perhaps the leg creatine stores were already “topped-up” with creatine leaving very little room for improvement; however, the upper body musculature stores may not have been so saturated leaving a greater room for improvement. This theory is supported by another study that trained only one leg and not the other; the researchers observed greater creatine stores in the trained leg compared to the untrained leg.

So, what’s the deal for the contrasting body composition results? The researchers, although not certain, speculated that change in body water status (creatine tends to retain more water in the tissues) in the trained group, may have influenced the results. They suggested that the underwater weighing data may have been tainted, therefore, overestimated the body fat levels in the creatine group. So, the researchers concluded that the effect on creatine body composition is inconsistent.

That said, this information can be useful for those athletic females contemplating the taking of creatine monohydrate to improve their performance.

STUDY 2

Researchers compared the physiological responses of 19 recreationally active females (university students) during 11 weeks of resistance training (RT) and rowing. These responses included MaxVO2, 1RM, and Time to Exhaustion. The women were divided into three groups: lift-only (LO), lift-row (LR) and row-lift (RL). Subjects trained three times a week performing six leg exercises (leg press, squat, LX, LC, deadlift, heel raises) for two sets of 10 reps (1st two weeks), three set of 10 reps (3rd to 4th week), four sets of 10 reps (for rest of study); total time was 45 minutes. One minute recovery between sets at a slow speed per rep. Aerobic exercise consisted of rowing on a Concept II rower for 45 minutes at an intensity of 70 percent MaxVO2; with stroke rate increasing by 1stroke/min every week.

The Results

One repetition maximum lifts improved in all groups: LR = 27 percent, RL = 27 percent; LO = 26 percent; suggesting that the sequence or order of training approaches did not influence strength training adaptations. Changes in MaxVO2 increased significantly for the LO and LR groups, RL showed the least improvement: LO = 9.3 percent, LR = 8 percent, RL = 5.3 percent. The researchers believe that the reason why the RL group did so poorly was due to one subject’s MaxVO2 score had decreased instead of improving which threw-off the results for this group. Surprisingly, the lift-only group showed a 5.3 percent improvement in MaxVO2, which is unusual, but not unseen in other studies using circuit resistance training. This increase in the LO group was thought to be due to the short rest periods between sets, adding a stronger aerobic component to the resistance training. Time to exhaustion during rowing was not significantly different for all groups.

Andre’s Notes

This study suggests that there is no interference in strength development when combining resistance training before or after an aerobic activity. This is great information for instructors; they now have an article that they can refer to when answering the question “Should I weight train before or after my cardio.”

However, please keep in mind that several studies exist that have demonstrated how strength performance is compromised when performed after aerobic training.

So, now what? Well, your decision to weight train before or after aerobic training, will be largely based on your goals; if you want size and significant strength improvements, the research literature supports more the argument to perform aerobic activities after the weight training session, perhaps later in the day or on another day altogether. If your goal is to tone and firm up, then your choice will be based on the format you find more enjoyable, comfortable and motivating.

References:

  1. ACSM. The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness in healthy adults. Med Sci Sports Exerc. 22: p. 265-274. 1990.
  2. Bell G, Peterson S, Quinney H. and Wenger H. Sequencing of endurance and high-velocity strength training. Can J Sports Sci. 13: p. 214-219, 1988.
  3. Bell G, Peterson S, Wessel J, Bagnall K, and Quinney H. Adaptations to endurance and low-velocity resistance training performed in sequence. Can J Sports Sci. 16: p. 186-192, 1991a.
  4. Hickson R. Interference of strength development by simultaneously training for strength and endurance. J Appl Physiol 45: p. 255-63. 1980.