Strength Training, stretching

August 20, 2017

Warming Up Prior to Resistance Training: An Excerpt from “Strong & Sculpted”

Below is an excerpt from my book, Strong & Sculpted that discusses my current approach to warming up prior to resistance training. I neglected to include a chapter on the topic in my book, M.A.X. Muscle Plan so for those following this program, the same info applies.

Warm-Up
To prepare your body for the demands of intense exercise, you should warm up prior to your lifting session. The warm-up contains two basic components: a general warm-up and a specific warm-up. Here’s what you need to know about each component for a safe, effective workout.

General Warm-Up
The general warm-up is a brief bout of low-intensity, large muscle–group, aerobic-type exercise. The objective is to elevate your core temperature and increase blood flow, which in turn enhances the speed of nerve impulses, increases nutrient delivery to working muscles and the removal of waste by-products, and facilitates oxygen release from hemoglobin and myoglobin.

A direct correlation exists between muscle temperature and exercise performance: when a muscle is warm, it can achieve a better contraction. As a rule, the higher a muscle’s temperature is (within a safe physiological range), the better its contractility. And because better contractility translates into greater force production, you’ll ultimately achieve better muscular development.

What’s more, an elevated core temperature diminishes a joint’s resistance to flow (viscosity). This is accomplished via the uptake of synovial fluid, which is secreted from the synovial membrane to lubricate the joint. The net effect is an increase in range of motion and improved joint-related resiliency. Better yet, these factors combine to reduce the risk of a training-related injury.

Suffice it to say that the general warm-up is an important part of a workout.

Virtually any cardiorespiratory activity can be used for the general warm-up. Exercises on equipment such as stationary bikes, stair climbers, and treadmills are fine choices, as are most calisthenic-type exercises (e.g., jumping jacks, burpees). Choose whatever activity you desire as long as the basic objective is met.

The intensity for the general warm-up should be low. To estimate intensity of training, I like to use a rating of perceived exertion (RPE) scale. My preference is the category-ratio RPE scale, which grades perceived effort on a scale from 0 to 10 (0 is lying on your couch, and 10 is an all-out sprint). Aim for an RPE of around 5, which for most people is a moderate walk or slow jog. You can use the talk test as an intensity gauge. With this method, you base intensity on your ability to carry on a conversation; if you have to pause to take a breath while speaking a sentence, you’re working too hard.

Five to ten minutes is all you need for the general warm-up—just enough to break a light sweat. Your resources should not be taxed, nor should you feel tired or out of breath either during or after performance. If so, cut back on the intensity. Remember, the goal here is merely to warm your body tissues and accelerate blood flow—not to achieve cardiorespiratory benefits or reduce body fat.

Specific Warm-Up
The specific warm-up can be considered an extension of the general warm-up. By using exercises that are similar to the activities in the workout, the specific warm-up enhances neuromuscular efficiency for the exercise you are about to perform. In essence, your body gets to rehearse the movements before you perform them at a high level of intensity, translating into better performance during your working sets.

To optimize transfer of training, the exercises in the specific warm-up should mimic the movements in the workout as closely as possible. For example, if you are going to perform a bench press, the specific warm-up would ideally include light sets of bench presses. A viable alternative would be to perform push-ups because the movement pattern is similar to that of a bench press, although the specificity, and thus transfer, would not be as great as with light sets of the given movement. Always stop specific warm-up sets well short of fatigue. The object is not to fatigue your muscles, but rather to get a feel for the exercise so that you’re physically and mentally prepared for intense training.

The specific warm-up is particularly important when training in low-repetition ranges (~ five reps or fewer). I recommend at least a couple of specific warm-up sets per exercise during low-rep training. As a general rule, the first set should be performed at ~40 to 50 percent of 1RM; and the second set, at ~60 to 70 percent of 1RM. Six to eight reps is all you need in these sets—any more is superfluous and potentially counterproductive. Following the specific warm-up, you should be ready and able to plow into your working sets.

The need for specific warm-up sets in medium- to high-rep-range training remains questionable. I recently collaborated on a study that investigated the effects of a warm-up on the ability to carry out repetitions to failure at 80 percent of 1RM (a weight that allows performance of about eight reps) in the squat, bench press, and arm curl (Ribeiro et al., 2014). The verdict: Warming up showed no beneficial effects on the number of repetitions performed in medium- to high-rep-range training nor in a measure called the fatigue index, which is a formula that assesses the decline in the number of repetitions across the first and last sets of each exercise.

At face value these results suggest that warming up is pretty much useless prior to submaximal resistance training. Despite the currently held belief that a specific warm-up enhances exercise performance, no benefits were seen when compared to no warm-up at all. Intuitively, this seems to make sense given that the initial repetitions of a submaximal lifts are in effect their own specific warm-up, and increasing core temperature might be superfluous from a performance standpoint when multiple reps are performed.

It should be noted, however, that we found a slight advantage to performing a specific warm-up prior to the squat (although results did not rise to statistical significance); the specific warm-up prior to the biceps curl seemed to be somewhat detrimental. Thus, more complex movement patterns seem to benefit from the practice effect of a specific warm-up, although this would be of no value prior to simple exercises.

Taking the evidence into account, here’s my recommendation: When performing medium-rep-range work (8 to 12 reps per set), perform a specific warm-up prior to multijoint free weight exercises. One set at about 50 percent of 1RM is all you need to obtain any potential benefits.

Specific warm-up sets are not necessary when training with high reps (15+ reps per set). In this instance, because you’re already using light weights, the initial repetitions of each working set serve as rehearsal reps. What’s more, performance of warm-up sets is counterproductive to the goal of maximizing training density to bring about desired metabolic adaptations.

What About Stretching?
Static stretching is commonly included as part of a prelifting warm-up. This method of flexibility training involves moving a joint through its range of motion to the point where you feel slight discomfort, and then holding the position for a period of time (generally about 30 seconds). Most protocols involve performing several sets of static holds and then moving on to stretches for other muscles. It’s commonly believed that the addition of stretches to a warm-up further reduces injury risk while enhancing physical performance.

In recent years, however, the benefits of preexercise static stretching have come under scrutiny. A large body of research shows that the practice does not decrease injury risk (Thacker et al., 2004). Yes, improving flexibility can conceivably help in injury prevention. Tight muscles have been implicated as a cause of training-related injury, and improving flexibility can reduce this possibility. Because a stretching exercise improves range of motion, including it in an exercise program can enhance overall workout safety. However, the benefits are not specific to stretching prior to training. All that matters is achieving adequate range of motion to properly carry out exercise performance.

The most important consideration here is to make sure your muscles are warm before performing static stretches. This reduces joint viscosity, ensuring that muscles and connective tissue are sufficiently prepped to endure passive or active lengthening.

So you might be thinking, Why not include some basic stretches after the general warm-up? After all, your core temperature is elevated and joint viscosity is reduced. What’s the harm, right?

Interestingly, evidence shows that static stretching performed before a workout can have a detrimental impact on exercise performance. This is most applicable to activities requiring high force output, such as heavy resistance training. The primary theory proposed to account for these performance decrements is a decrease in musculotendinous stiffness. The musculotendinous unit (the muscle and its associated tendons) is responsible for generating force to carry out movement. Like an overstretched rubber band, the musculotendinous unit with increased laxity following stretching impairs force transmission. The upshot is a reduced capacity to lift a given load.

However, caution needs to be used when applying this research to a lifting session. First, most of the studies in question used excessive stretching protocols, in some cases upwards of 30 minutes stretching a single joint! Most preworkout stretching routines involve only a few minutes per joint, and it’s highly questionable whether such brief stretching bouts have any performance-related detriments. Moreover, the vast majority of research on the topic is specific to high- strength and high-power activities. Whether negative effects are associated when training with medium- to high-rep schemes remains speculative.

Given the uncertainty of evidence, you’re best off performing static stretches immediately after your workout. Your body is already warm from engaging in intense exercise, and it generally feels good to cool down by elongating muscles that have been repeatedly contracted. Some research even shows that postworkout stretching may alleviate delayed-onset muscle soreness (see the sidebar What Causes Muscle Soreness After a Workout?), although the extent of the reduction probably isn’t all that meaningful (Henschke & Lin, 2011).

If you want to include some flexibility work prior to lifting, consider dynamic stretches: slow, controlled movements taken through their full range of motion. Examples are arm swings, shoulder circles, high steps, and hip twists. Choose dynamic stretches that are specific to the joint actions being trained in your workout. Perform several sets for each dynamic stretch, attempting to move the body segment farther and farther in a comfortable range with each set.

Contrary to popular belief, you don’t necessarily have to include a stretching component in your regular routine for general health and wellness. Increased flexibility results in decreased joint stability. Being too flexible, therefore, actually increases injury risk. Thus, stretch only those joints that are tight, and avoid any additional flexibility exercise for those that already have adequate range of motion to carry out your required activities of daily living.

Moreover, it’s important to note that resistance training in itself actually improves flexibility. Provided that you train through a complete range of motion, multiset lifting protocols produce similar increases in flexibility to those seen with static stretching routines (Morton et al., 2011). In essence, resistance training is an active form of flexibility training whereby a muscle is contracted and then immediately lengthened. When performed on a regular basis, it can keep you mobile and limber. We can therefore put to rest the myth that lifting slows you down and binds you up!