mainly stolen from https://mensfitness.co.uk/workouts/build-bigger-arms-with-just-one-pair-of-dumbbells/
Arm Day

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Diamond Press Up
Weight:
Reps: 12
Rest: 60s
Sets: 3
- Assume a press-up position, holding your body in a straight line from your head to your heels.
- Bring your thumbs and index fingers together so that they form a diamond shape underneath your chest.
- Lower with control, keeping your elbows pointing back rather than to the sides.
- Press back up and repeat.

2. Concentration Curl
Weight:
Reps: 10
Rest: 60s
Sets: 3
- Sit down and rest your right elbow just inside your right knee.
- Rest your free hand on your opposite knee but don’t press down on it to aid the move.
- Keep your upper body still and curl the dumbbell up to your chest.
- Squeeze your bicep at the top of the move, then lower with control.

3. Triceps Kickback
Weight
Reps:10
Rest: 60
Sets: 3
- Bend forwards at the hips and keep your back in its natural arch
- Start with your elbows bent at 90 degrees.
- Straighten your arms behind you, while keeping your upper arms as still as possible.
- Keep your core braced throughout the move to maintain a neutral arch in your spine.

4. Hammer Curl
Weight
Reps:10
Rest: 60
Sets: 3
- Stand with your back straight, your shoulders back and your core braced.
- Grip the dumbbells with palms facing inwards and tuck your elbows into your sides.
- Curl the weight without rotating your wrists and make sure you keep your elbows tucked in.
- Avoid rocking back and forth to keep the tension in your biceps.

5. Zottman Curl
Weight
Reps:10
Rest: 60
Sets: 3
- Stand holding dumbbells by your sides, with palms facing forwards.
- As you lift the weight, keep your elbows tucked into your sides.
- At the top of the move, rotate your wrists and lower the dumbbells with reverse grip to shift the emphasis onto your forearms.