Determining the Effect of Shoulder Flexion Angle on Latissimus Dorsi and Forearm Flexor Hypertrophy

The goal of this clinical trial is to learn the effect of training a muscle at a longer or shorter muscle length during resistance exercise in young and healthy adults. Participants will undergo two types of resistance training conditions that are randomly assigned to the left and right arm. The LATPULLDOWN (LPD) condition refers to performing an exercise that places the latissimus dorsi muscle at a long muscle length when the shoulder is elevated to 180° of shoulder flexion. The LATROW (LR) condition refers to performing an exercise that places the latissimus dorsi muscle at a shorter muscle length when the shoulder is elevated to 90° of shoulder flexion.

The main questions the trial aims to answer are:

1. Does resistance training the latissimus dorsi muscle at a long muscle length result in greater muscle growth than training at a shorter muscle length? 2. Does resistance training the latissmus dorsi muscle at long or short muscle lengths result in regional muscle growth differences of the latissimus dorsi?

We hypothesize that:

1. LAT PULLDOWN will induce greater hypertrophy compared to LAT ROW condition 2. LAT PULLDOWN will result in greater increases in 1RM compared to LATROW condition 3. LAT PULLDOWN and LAT ROW will result in angle specific differences in Isokinetic strength 4. LAT PULLDOWN will result in greater inferior Latissimus Dorsi hypertrophy 5. LAT ROW will result in greater superior Latissimus Dorsi hypertrophy

The investigators will compare the change in muscle volume and muscular strength between the LAT PULLDOWN and LAT ROW training conditions, which each participant will have the left and right arm randomly assigned to either exclusively LAT PULLDOWN or LAT ROW conditions.

Participants will:

* Resistance train the left and right arm with two separate conditions; LAT PULLDOWN and LAT ROW for 12 weeks, with the first and last weeks dedicated to only strength testing (Isotonic and Isokinetic) and measuring muscle volume via magnetic resonance imaging (MRI) * Visit the gym for resistance training 2 times per week * Visit the UBC MRI Research Facility in weeks 1 and 12 for MRI of muscle volume