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Wednesday, 21 April 2010

Climbing, training, questions & myths

Recently I have been reading up on specific training recommendations for climbing in order to prepare for the rock climbing season. There was some good advice but also some opinions that are not supported or that are contrary to the existing scientific evidence. The lack of scientific evidence does not necessarily mean that the recommended training does not work. It may well work and often very well especially for those that give the advice. However, certain types of training only work for some and in other cases the training might work but the explanation is wrong. Being an exercise physiologist I thought it would be good to comment on it. The following three questions interest myself and are relevant for climbing:

Question 1. I am following a training programme designed to increase climbing-specific strength but I don’t improve. What is the problem?
There is now evidence from solid studies showing that individuals respond very differently to endurance and strength training. For example, Monica Hubal and colleagues studied 342 women and 243 men that took part in the same 12 week, progressive strength training programme. They found that the size of the trained muscle changed from -2 to +59% and that strength changed from -32 to +149 (Hubal et al., 2005). The fact that one individual lost 1/3 of her/his strength despite training to increase strength suggests that there were some poorly controlled external factors but generally the message is that individuals will respond very differently to a strength training programme. So what's the lesson learned? Training recommendations designed to improve climbing-specific strength will only work very well for the MacLeods, quite well for Joe Average and not at all for the poor responders. Those that write training plans should point that out to the recipients.

Question 2. What training methods can I use to increase the percentage of fast/type II muscle fibres?
Rest is probably the best 'training' to get more fast muscle fibres. The reason is that all forms of exercise, including strength training, reduce the expression of the fastest type IIx fibres and increase the percentage of the slower, intermediate type IIa fibres (Andersen & Aagaard, 2000). The only thing that increases type IIx fibres is inactivity (Andersen & Aagaard, 2000) or accidentally denervation such as spinal cord injury (Biering-Sorensen et al., 2009). Thus the take home message is to train as little as necessary to increase strength and learn a movement if a high percentage of type IIx fibres is the key aim of a training programme. In other words, sprinters should not jog much. If a lot of training is necessary to increase glycolytic enzymes and mass then a tapering period (low volume) could help to let the percentage of type IIx fibres increase again.

Question 3. Can maximal neural activation only be achieved with near maximal contraction training (1 repetition strength training, hard bouldering, campus board)?

Strength depends on the size and composition of muscles and on the ability of the nervous system to activate the existing muscle. A high neural activation of muscle is important for athletes such as climbers and high jumpers because it means strength gain without increased weight/muscle mass. It is sometimes suggested that maximal neural activation can only be achieved with 1 repetition strength training, hard bouldering or campus boarding. This is probably not the case because near maximal neural activation can also be achieved with less intense contractions if they are repeated until failure or until one gets pumped, to use climbers language (Jungblut, 2009). So why is that? If a muscle generates a force say 50% of the maximum then initially only a limited of fibres need to be activated by the neural system to generate that force (= less than maximal neural activation). However, over time the PCR-ATP, and glycolytic system ‘fatigue’ in the contracting fibres (it would take pages to describe the exact mechanisms) and thus they lose force. In order to maintain the overall force, more neural activation is needed in order to recruit more fibres so that the fatigued and newly recruited fibres produce the 50% of the maximal force. At one stage all the fibres are that fatigued that we need maximal neural activation in order to recruit sufficient fibres to produce 50% of the maximal force and soon after we will be too fatigued to achieve 50% of the maximal force. This is the reason why a relatively easy crux move (requiring less than maximal force) high up on a pumpy route feels just as difficult and requires the same amount of teeth gritting than a brick hard move at the start of a boulder problem. Having said all of the above it is likely that near maximal contractions have benefits that exercise with less intense contractions to fatigue (and thus near maximal neural activation doesn’t have).

Reference List

Andersen JL & Aagaard P (2000). Myosin heavy chain IIX overshoot in human skeletal muscle. Muscle Nerve 23, 1095-1104.

Biering-Sorensen B, Kristensen IB, Kjaer M, & Biering-Sorensen F (2009). Muscle after spinal cord injury. Muscle Nerve 40, 499-519.

Hubal MJ, Gordish-Dressman H, Thompson PD, Price TB, Hoffman EP, Angelopoulos TJ, Gordon PM, Moyna NM, Pescatello LS, Visich PS, Zoeller RF, Seip RL, & Clarkson PM (2005). Variability in muscle size and strength gain after unilateral resistance training. Med Sci Sports Exerc 37, 964-972.

Jungblut S (2009). The correct interpretation of the size principle and its practical application to resistance training. Medicina Sportiva 13, 203-209.

1 comment:

Anonymous said...

Some interesting stuff. Keep it up Henning! Personally I can confirm that resting does the trick.