Training Variables that drive different weight selection
First note the INTENSITY listed in the exercise notes. It will be written as "RPE" or "RIR" which stand for "rate of perceived exertion" or "repetitions in reserve". Most of our workouts list INTENSITY as "RPE" and are on a scale from 1-10. During a warm-up block, the RPE will usually be 5-6 out of 10. This means you can perform the number of repetitions listed and the last repetition will feel 'moderate' and you would likely be able to perform roughly another 25% of what you completed. For example, if you completed 10 repetitions of an exercise and when you finished, you felt like you could perform another 2-3 repetitions with good form.
The key is knowing when your form is starting to fail.
If the RPE is 10/10, the last repetition should be extremely hard, but you can maintain proper form throughout the movement.
If you do find an exercise that uses RIR, the concept is very similar. If the RIR is '0', this is equivalent to an RPE of 10/10.
It will take some experimenting to find the correct weight to achieve the target RPE or RIR and if the weight you initially select is too hard or too easy, it is OK to do less or more then the recommended repetitions.
Don't forget to use the HISTORY button
to see what you did the last time you performed the exercise. Check out this article to see how to view the history of what you lifted for an exercise in your previous session.
Here is a video that is also helpful in learning How to Select the Proper Weight.
Dumbbell weight guide for strength training
Here is a helpful chart for those new to strength training to know what range of dumbbells to grab when learning to strength train:
Light Weights (5-10 lbs)
You should be able to comfortably perform 6-8 lateral shoulder raises with lighter weights. These are ideal for accessory exercises and warm-ups.
Medium Weights (10-30 lbs)
You should feel comfortable pushing this weight over your head but start to tire around 15 repetitions. This range is versatile for a variety of exercises.
Heavy Weights (20-60 lbs)
You should tire around 15 repetitions for a goblet squat using this weight. These are your heavy hitters for building power and strength.