Heavy or Light Weights: Which Is Best?

heavy weights or light weight?

There is often a lot of confusion in weight training, with people thinking that high-rep low-weight training will tone your muscles and low-rep high-weight training will increase muscle mass, however, both of these are not particularly right.

We are going to put this straight so that you understand how to effectively train for the outcome that you intend.


What Is Considered A Light Weight And A Heavy Weight?

Weight is relative to the individual. The only way to measure whether a weight is heavy or light is to measure the individual’s ability to move the weight in a controlled manner, for a number of sets, or for specific time period. Going to failure these are the rep ranges that could be considered heavy, moderate, and light:


1-5 reps is considered heavy

6-15 reps is considered moderate

15+ reps is considered light


Benefits/Pitfalls of Light Weight & High-Reps


  • Builds muscle endurance
  • Builds slow twitch fibers (Type 1 – Red oxidative muscle fibers)
  • Low chance of injury
  • Allows for full control of a weight throughout the whole range-of-motion



  • Doesn’t build substantial strength or power
  • On its own, it’s not the most efficient/effective way to build muscle mass


Benefits/Pitfalls of Heavy Weight & Low-Reps


  • Builds strength and power
  • Builds fast twitch muscle fibers (Type 2b – Fast glycolytic fibers)
  • Strengthen ligaments
  • Improve the central nervous system



  • Lower control over weight
  • Higher chance of inflicting injury (muscle/ligament tears)
  • Increase chance of central nervous system burnout


What Are You Training For?

To Increase Muscle Tone – Many people believe that muscle tone is the result of high rep exercise causing firm muscles with higher definition level. This is not true. ‘Muscle tone’ is simply denser, larger muscle that has definition. This is achieved through the increase of muscle mass and the reduction of body fat to a point at where the muscle can protrude and show the definition (usually below 10% body fat in men).


To Increase Muscle Endurance – To increase the muscle endurance you should be aiming for high reps, thus a low weight must be lifted to maintain the volume of reps required to stimulate the muscle fibers associated with muscle endurance (red oxidative – Type 1)


To Increase Muscle Hypertrophy (Mass) – To increase muscle mass (hypertrophy) you should be aiming for high-intensity exercise at a moderate weight, and a rep range between 8-15 reps per set. However, this is not set in stone by all means. There is a number of training methods that aid in the development of muscle mass which fall outside of the moderate weight range (8-15 rep range).


To Increase Power/Strength – To increase muscular strength to its maximum capacity you have to continually overload your muscles with very heavy weights loads. Usually 1-3 reps is the parameters for powerlifting, where the focus is about stimulating the central nervous system to develop its neural pathway, and to increase the responsiveness of the nervous system to “fire” quicker in response to the stimulation inflicted upon it when an individual is exerting a high force, such as lifting an extreme weight load at speed.

Power is the amount of force you can exert in one go. So this type of training is focused more on the one rep max, whilst strength is the amount of weight load you can lift – they both essentially interlink.


What You Should Do…

For Muscle Endurance

If you are looking to develop muscle endurance then obviously light weight loads with high reps ranges are best suited. Try not to steer too far into high weight loads, however, as this will, in the long run, increase the Type 2 muscle fibers, which will increase your overall mass and this will reduce the muscle’s ability to endure stress for higher periods. Sticking to this training method would be suited for the endurance athletes and specific sporting situations and perhaps not for the individual that wants to get fitter for appearance/aesthetics.


For Muscle Mass

So you want to increase your mass? Mass training has always focused not on heavy or lightweight, but moderate weight loads, with moderate rep ranges (usually 8-15). This is what the majority of your training should be made up of – if building mass is what you are aiming for. However, sticking adherently to this will mean that you may not be training optimally for greater mass development. There are two cases that can be made for this:

  1. Heavy weight or strength training can make up an important part of your mass building regime. Arnold Schwarzenegger was adamant about including strength training into his regime every so often. How does this training help? It does two things; psychologically stacking on heavy weights and lifting them even for short rep ranges, will increase your confidence to lift and control a weight – when you bring the weight load down and increase the reps (for hypertrophy training). The second case is that by adding strength training into your regime you will obviously get stronger. To build mass your ultimate goal is to perpetually increase the weight that you lift over time. There are times when training in which you plateau, struggling to lift more weight while sticking to the moderate weight loads and moderate rep range. You must “shock your muscles”. Strength training will stimulate the Type 2B fibers. As your strength increases from strength training, your hypertrophy (mass) training will inherently improve, as you will be able to set the weight higher – breaking the boundaries.


  1. Utilizing lightweights has its benefits too. For the inexperienced, they may lack poor form and be unable to maximise and focus the contraction onto the intended muscle (it’s very common, even for the experienced). Lightweights are good to use because you can use them to critique your form. This technique allows you to flex and contract a muscle effectively, whilst also adapting/critiquing the motion of the exercise – so that form is perfected. Heavier weights often prevent you from feeling whether the target muscle is contracted optimally – as your mind is focused on pulling/pushing/lifting a weight from point A to point B.


Light weights with high reps can also be added to a training session, to stimulate a muscle/muscle group to its max. Best performed at the end of each session when your muscles are relatively fatigued. It allows you to push out a few more sets, adding to the total volume lifted during that session. It is also a technique to increase muscle pump (which has benefits in mass training).


For Muscle Strength/Power

Want to get stronger and develop power? Then the high weight loads are a must. This means that you will perform low reps per set – due to the high intensity of the exercise.

With strength and power training, you may not be focusing the tension on a specific muscle as you would in hypertrophy (mass) training – this is due to the lifter utilizing a higher number of muscles or muscle groups to perform the lift. The weight load gets displaced across the muscles quickly, unlike in mass training where there is a greater focus to maintain tension on a particular muscle or muscle group for a greater time period (Time Under Tension – TUT).

Remember though that this type of training isn’t optimal for mass building. It will build mass as your strength increases, due to the increase of Type 2B muscle fibers, but to increase mass significantly you need to promote the Type 2A fibers.


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