Strength Training and “aerobic conditioning” during the off-season
Professionalcycling.info is a strong advocate of endurance strength training over the traditional heavy lifting programs used by most cyclists. An off-season plan that includes an endurance lifting program and circuit training produces dramatic results for many of our riders every season by building maximal aerobic capacity and muscular endurance.
Circuit training is a popular form of general fitness training that is extremely valuable as a maintenance program for aerobic conditioning muscular strength during off-season strength training. The off-season challenge for the endurance athlete is to sustain a minimal level of aerobic conditioning while taking on the rigorous and demanding routines of strength training.
Lifting heavy weights tears down large amounts of muscle tissue and requires longer periods of recovery time to rebuild the muscle before it can be trained again. This can make aerobic endurance training difficult to fit into the weekly schedule.
Using circuit training before and after the strength training phase will help maintain good levels of aerobic conditioning during the off-season and provide quality transition training into and out of the gym. This article will discuss the research that has examined the physiological benefits of aerobic circuit training. Most of the useful research and published papers on the subject date back to the 1970’s and 1980″s. The reason for this is that once a general consensus has been reached regarding the effects of a particular type of training there is not much need to re-research the topic and this is a fairly simple, straight forward form of exercise that does not require much additional study. Aerobic circuit training remains a staple component of training programs across a wide spectrum of sports and athlete training and so it is worth a little time reviewing the highlights to gain a better understanding.
The type of circuit training involves 10-12 standard “push-pull” weight-training exercises that recruit an equal number of upper and lower body muscle groups. One complete “circuit” combines these exercises into a brisk paced, non-stop routine alternating between upper and lower body exercises. The athlete will spend roughly 25-30 seconds at each exercise “station” completing 15-20 reps. The only rest taken between stations is the time it takes to get to the next exercise and set up the resistance. A typical circuit training session will include 3-4 full circuits. Allowing for about 45 sec per exercise a full circuit of 12 exercises will take about will 10-12 minutes and is followed by 10 minutes recovery.
The specific resistance settings for each exercise are about 65-70 % of 10RM (personal 10 rep maximum capacity). There is no “maximal lifting” or “work to failure” and the focus is on aerobic conditioning. The sustained and repeated aerobic level intensity is the key to success. Circuit training can be used for 3-4 weeks as a “preparation” for resistance training with heavier weights or as a general conditioning program for 3-4 at the end of a strength training phase before returning to full time training on the bike.
Circuit training is an effective way to maintain aerobic conditioning while taking a much needed break from sport specific training in the off season. A 1981 study of circuit training protocols by Gettman and Pollock suggest that 8-12 weeks of the kind of circuit session described above resulted in up to 5% improvement in Vo2max. This is significantly less than the improvements gained from sport specific training methods but it does provide maintanence level conditioning during an off-season strength or cross training phase. Comparatively, research has shown that cycling at around 75% of max heart rate for 30-45 minutes, three times a week for 8-12 weeks can improve Vo2max by as much as 20% in untrained subjects. For the endurance athlete this translates into retention of vital aerobic fitness.
During a typical circuit training session heart rates should reach an average of around 80% of max and oxygen consumption will reach about 40-50 % of Vo2max. These are considered the minimum levels for improving aerobic fitness conditioning. The rest between stations (exercises) is very important to the success of the workout. Rest intervals of 60 sec between stations produce minimal improvement in Vo2max so keeping the rest periods short is important to the aerobic-training stimulus of the workout. This is accomplished by alternating between upper and lower body exercises. While the arms are recovering the legs are working and the prescribed heart rate is maintained throughout the workout. Energy consumption has been shown to average about 6-9 kcal//min depending on bodyweight. This makes circuit training a very useful form of low to moderate level aerobic training that is useful for transition and cross training during the off-season.
It is interesting to note that improvements in Vo2 from circuit training are more pronounced with untrained subjects that with trained athletes. This is consistent with the principle of progression, which states, “As fitness increases, overall load and intensity must also increase to stimulate adaptation and improvement.” It suggests that for the better conditioned athlete a higher intensity of aerobic effort is needed for further improvement. Some research has taken this idea further in studying the effects of sport specific aerobic training and circuit training for maintaining fitness.
During a separate, 24-week study in 1982, Gettman et al, reported that after eight weeks of circuit training a group of trained athletes improved their Vo2max by 3%. The same group then completed eight weeks of sport specific training and posted an average increase in Vo2 max of 8%. This supports the widely accepted notion that sport specific aerobic training is more effective that circuit training. During the next 8 weeks half the group returning to sport specific training while half went back to circuit training. At the end, both groups had maintained all of the Vo2max improvements gained from the original sports specific training. This strongly supports the notion that circuit training is a useful way for athletes to stay in shape while from sport specific training during the off-season or injury rehabilitation.
Studies have also shown that blood lactate levels increase dramatically during circuit training, suggesting an anaerobic component to the training. This is consistent with the increased muscle cell recruitment associated with resistance training and the required anaerobic glycolysis needed to fuel the muscles for contraction. This suggests that circuit training, for trained athletes, may be as beneficial in developing anaerobic muscular endurance as aerobic fitness because of the adaptation of tolerance and buffering of elevated lactic acid.
The endurance lifting program we use clearly benefits from this adaptation with the high sets and reps routine of sub maximal resistance training. The program builds strength and muscular endurance at very high aerobic levels as an alternative to traditional power lifting weight routines. As a compliment to sport specific training, circuit training could also be useful as an alternative form of anaerobic conditioning training, combining high-intensity anaerobic bouts of weight-training exercises with low-intensity aerobic recovery periods.
Since energy metabolism happens in muscle cells, circuit training is an effective method for increasing energy metabolism by increasing lean body mass. The resistance work involved in circuit training encourages muscle mass development and increases lean body mass (% of lean muscle) over traditional, sports specific aerobic training. Traditional aerobic training decreases total body weight by burning excess body fat but does little to increase muscle mass. In a sport like cycling, muscle atrophy will occur over time as the body adapts to the specific strength needs on the bike and retains the optimal amount of muscle need for the work. This explains the need for off-season strength training and “rebuilding” lost muscle mass for serious endurance riders.
It becomes easier to maintain the lower body fat percentage or reduce body fat even further when the increase in muscle mass increases metabolism and raises the basal metabolic rate and overall daily calorie expenditure. The real benefit for the endurance rider is that increased muscle lean muscle increases aerobic energy metabolism and promotes more efficient use of oxygen and fatty acids for fuel. This is a very attractive long range conditioning strategy that doubles as a very effective method of weight management during the off-season.
The consensus of past research demonstrates that circuit training can make moderate improvements in aerobic fitness but what happens when some other workout protocols are tried that have increased aerobic activity as part of the routine?
Again, Gettman et al (1992) compared the effect of two types of circuit training on Vo2 max. Session A was a typical weight circuit using 30 sec work bouts at 40% of 1 RM with 15 sec rest between stations. Session B was the same circuit routine but 30 sec of jogging inserted between each station instead of rest to increase the total aerobic workload. The session “A” group improved V02max by 12% while session B group improved it by 18%. Both groups reduced body fat and increased strength at similar levels.
The effect of extra aerobic activity during circuit training and the increase in aerobic conditioning was also shown by Mosher, et al (1994). This study used a circuit session comprising 3 mins of non-resistance aerobic activity at 75% of max heart rate, followed by a five-station weight circuit at 40-50% of l RM. This routine was repeated five times with minimal rest between and the session lasted 45 minutes. The researchers found that after 12 weeks that subjects improved Vo2max by 18%, which is similar to the gains produced by traditional, sports specific aerobic programs. In the group, body fat was reduced by 3% and strength increased by 20%.
These two studies suggest that adding additional aerobic workload between the weight-training exercises produces better aerobic fitness. This kind of aerobic circuit training can be almost as good as traditional aerobic methods for building and maintaining aerobic conditioning. However, these two studies only used average-to-moderately fit subjects with no experience in training. It is possible that fitness gains may not be so great for the trained or elite level athlete. For a competitive cyclist, this type of aggressive circuit training could be a good substitute for traditional aerobic training during off-season strength as a challenging cross training activity.
So, what does all this mean to you, the cyclist wanting to improve you performance? To start with, maintenance of aerobic fitness is vital to your year round preparation. I like to give my riders a break from the demands of training on the bike and circuit training, and other forms of cross training are great for that. As we have seen, different types of circuit training workouts produce a wide range of positive results.
Circuit training exercises, using moderate resistances for around 30 seconds with short rests produces modest aerobic fitness gains, moderate strength gains, a reduction in body fat and increase in lean body mass increase. Circuits with longer rests have no aerobic benefit but do increase lean body mass and strength.
Circuit training with higher resistance can be seen as method of interval training with high lactate levels and are good for anaerobic conditioning. Aerobics circuits with additional aerobic workload inserted between exercise stations have added aerobic value but this adaptation is not as effective for elite athletes. The expansion of this idea is the Performance Sports Endurance Lifting Program, which has produced substantial gains in power and endurance for trained athletes.
Circuit training may be best for beginners and those of average fitness looking to tone up and get in shape but is also an effective form of cross training and preparation for heavier lifting that helps eliminate common weight room injuries. Athletes can use circuit training early in the off-season as basic strength and conditioning work, or as an alternative anaerobic interval training method to help maintain aerobic fitness.